Vol. 51 No. 1 Winter 2017 Colorado Birds Vol 51/CB_2017... · lower 48 states and Alaska. Serious...

Vol. 51 No. 1 Winter 2017

The Colorado Field Ornithologists’ Quarterly

Colorado Birds

Colorado's 500th SpeciesBarn Owl Nest BoxesPop Quiz: Green Specula

2 Colorado Birds Winter 2017 Vol. 51 No. 1

Colorado Field OrnithologistsPO Box 929, Indian Hills, Colorado 80454

cfobirds.org

Colorado Birds (USPS 0446-190) (ISSN 1094-0030) is published quarterly by the Col-orado Field Ornithologists, P.O. Box 929, Indian Hills, CO 80454. Subscriptions are obtained through annual membership dues. Nonprofit postage paid at Louisville, CO. POSTMASTER: Send address changes to Colorado Birds, P.O. Box 929, Indian Hills, CO 80454.

Officers and Directors of Colorado Field Ornithologists: Dates indicate end of cur-rent term. An asterisk indicates eligibility for re-election. Terms expire at the annual convention. Officers: President: Doug Faulkner, Arvada, 2017*, [email protected]; Vice Presi-dent: David Gillilan, Littleton, 2017*, [email protected]; Secretary: Chris Owens, Longmont, 2017*, [email protected]; Treasurer: Michael Kiessig, Indian Hills, 2017*, [email protected]

Directors: Christy Carello, Golden, 2019; Amber Carver, Littleton, 2018*; Lisa Ed-wards, Palmer Lake, 2017; Ted Floyd, Lafayette, 2017; Gloria Nikolai, Colorado Springs, 2018*; Christian Nunes, Longmont, 2019

Colorado Bird Records Committee: Dates indicate end of current term. An asterisk indicates eligibility to serve another term. Terms expire 12/31.

Chair: Mark Peterson, Colorado Springs, 2018*, [email protected]

Committee Members: John Drummond, Colorado Springs, 2016; Peter Gent, Boul-der, 2017*; Tony Leukering, Largo, Florida, 2018; Dan Maynard, Denver, 2017*; Bill Schmoker, Longmont, 2016; Kathy Mihm Dunning, Denver, 2018*

Past Committee Member: Bill Maynard Colorado Birds Quarterly:

Editor: Scott W. Gillihan, [email protected]

Staff: Christy Carello, science editor, [email protected]; Debbie Marshall, design and layout, [email protected]

Annual Membership Dues (renewable quarterly): General $25; Youth (under 18) $12; Institution $30. Membership dues entitle members to a subscription to Colorado Birds, which is published quarterly. Back issues/extra copies may be ordered for $7.50. Send requests for extra copies/back issues, change of address and membership renewals to [email protected]. Contributions are tax deductible to the extent allowed by law.

COPYRIGHT © 2017 by Colorado Field Ornithologists. Reproduction of articles is permitted only under consent from the publisher. Works by U.S. and Canadian governments are not copyrighted.

The Colorado Field Ornithologists’ Quarterly Vol. 51 No. 1 Winter 2017

PRESIDENT’S MESSAGE .......................................... 4Doug Faulkner

CFO BOARD MEETING MINUTES ............................ 6Chris Owens

SAMUEL WASHINGTON WOODHOUSE .................... 9Bob Righter

FIRST COLORADO RECORDOF COUCH'S KINGBIRD..........................................13Dave Leatherman

THE EFFECTS OF FLOODING ON THE AVIANCOMMUNITY OF CHATFIELD STATE PARK ...........20Francis Commerçon

NEWS FROM THE FIELD: SUMMER 2016 ..............30David Dowell

THE HUNGRY BIRD ...............................................38Dave Leatherman

COMMON POORWILL .............................................44Jonathan Gendzier and Jonathan Poe

BARN OWLS ............................................................45Scott Rashid

IN THE SCOPE ........................................................51Tony LeukeringCouch’s King-

bird in Lamar on 19 April 2016. Photo by David Leatherman


PRESIDENT’S MESSAGE

Doug Faulkner

By the time you read this 2017 will have started and the doldrums of Colorado’s short days (i.e., less birding opportunity) will be wearing on us. We’ll be keeping tabs on Cobirds regarding the whereabouts of rosy-finches and various gulls and anxiously waiting to hear of the year’s first Cinnamon Teal, the avian harbinger of spring in Colo-

rado. The new year is also a time of anticipation for birders for another reason—at least the ones that rou-tinely keep a year list—a time for a fresh start. Even the first House Sparrow is relevant, although the species can be largely ignored the remaining 364 days of the year.

I do keep a year list and have since 1993, the first year I started birding seriously. This spreadsheet is rather simple with species listed in the rows and years for the columns. The numbers are modest, averaging 324.8 species per year within the lower 48 states and Alaska. Serious Colorado listers can achieve that just in the state, let alone adding in out-of-state travel for business or to visit relatives. While look-ing at this spreadsheet recently I noticed one curious pattern—my yearly totals made a dramatic jump in 1996, stayed respectable through 2005, then dipped to a level of some blushing during the past 10 years.

I’m talking in the 260–270 species range for the past decade when I was used to reaching 400.

Turns out, the initial surge coincides with my first birding adven-tures away from Indiana in 1996 when I worked for the then–Colo-rado Bird Observatory, then in Louisiana, Mississippi, and Texas later that year. For the ten-year span of 1996–2005, birding was my pas-sion. Day in and day out. To work and from work. During work. Dur-ing my wedding. It was that way until about the time my first-born turned one year old in 2005. Suddenly listing became a luxury and not a self-imposed mandate. As my two children have grown and family and work responsibilities have increased, time to go birding has not only dwindled but I find that listing does not have that all-

Colorado Birds Winter 2017 Vol. 51 No. 1 5

consuming draw it did ten years ago when I chased every reported rarity I could or went looking for my own.

Sure, each spring I tell myself to get out during warbler migration, in the summer to visit the eastern playas and reservoirs for shorebirds, and in the fall to try to catch up on what I missed by not going out in the spring and summer. But it never seems to work that way. Instead I spend time doing homework or playing catch—even when there is a rare bird only 15 miles away that ten years ago I would have dropped everything to go see.

Nonetheless, I’m still excited at the prospect of the new year list. Maybe this year my kids will take an interest in birding and we can build memories of chasing rare birds or enduring epic road trips or just visiting the local park with binoculars in hand. And if they don’t, that’s okay. I’ll still tell myself to go birding during peak migration and maybe I will. If I do, I hope to see you out there too (and please don’t forget to tell me about any rarity that’s within, say, 5 miles).

Photo Editor NeededIf you are knowledgeable about Colorado’s birds, have experience with digital photos (including the skills and software to do basic editing: crop-ping, resizing, etc.), and have a few hours to spare for each quarterly issue, please consider volunteering as the Colorado Birds Photo Editor. If you are interested, please contact Scott Gillihan, Editor ([email protected]).


CFO BOARD MEETING MINUTES

10 September 2016Pikes Peak Community CollegeColorado Springs, Colorado

Chris Owens

President Doug Faulkner called the meeting to order at 11:39 a.m. after a pre-meeting birding outing. The sighting of the meeting was a long-tailed weasel in front of the building where the meeting was taking place. Other officers present included Vice President David Gillilan, Secretary Chris Owens, and Treasurer Michael Kiessig; di-rectors present were Amber Carver, Lisa Edwards, Gloria Nikolai, and Christian Nunes. Directors Christy Carello, Ted Floyd, Scott Gillihan, and Mark Peterson sent their regrets.

To begin the meeting, the continu-ing board members warmly welcomed two new board members, Gloria Niko-lai and Amber Carver.

Secretary’s report: Owens’ min-utes from the 7 May 2016 annual meeting were approved.

Treasurer’s report: Michael Kies-sig had previously submitted his report electronically to the board members.

The board discussed the costs of holding a convention in Steamboat Springs in 2017, compared to the 2016 convention in Lamar. Expected costs will be higher while revenue from registration fees are difficult to predict. Revenue from the 2016 con-vention was about the same as the 2015 convention, despite higher at-tendance in 2016, in part due to more free registrations for field trip leaders. But costs were lower, given both lower facility charges and a generous dona-tion that covered most of the cost of the welcome picnic, resulting in an

overall profit from the Lamar conven-tion.

Board members approved a modest increase in compensation of $100.00/journal issue for the editor of Colo-rado Birds. Such compensation will be made retroactive to journal issue 50.2, the April 2016 issue.

Following the death of Ron Ryder, CFO received a request to donate to the scholarship fund being established at Colorado State University in Dr. Ryder’s name. The scholarship will be in perpetuity and awarded to students studying birds. The general consensus of the board was that Dr. Ryder was in-strumental in moving Colorado bird-ing and field ornithology forward, es-pecially through CFO, and the board voted to make a donation of $2,000.

2016 Steamboat Convention Planning: Roles and Responsibili-ties: Board members agreed that the convention will be held 1–5 June 2017.


David Gillilan has done some up-front work meeting with representa-tives of various venues in Steamboat Springs. The board approved a tenta-tive venue recommended by David realizing finalization dependent upon additional information currently be-ing prepared for CFO by the chosen venue. A discussion regarding fees for the 2017convention will be held af-ter complete expense information has been received.

President Faulkner appointed Da-vid Gillilan and Lisa Edwards to over-see the convention planning. David and Lisa announced that CFO mem-ber Linda Lee had volunteered to help with event planning logistics, and the board expressed its pleasure to have her on the 2017 convention team. The board expects to name other CFO board members and volunteers to handle additional logistics for the Steamboat convention as planning proceeds.

Succession for Board of Directors positions: Board members are aware that all four officer positions and two non-officer board positions will need to be voted on at the 2017 annual meeting in Steamboat Springs. While some of these positions are likely to be filled by existing board members, one officer (Doug) and two board members (Lisa and Ted) will be reaching term limits set forth in CFO’s bylaws. The Board reviewed the qualifications ex-pected of board members and set up a process for recruiting and vetting can-didates for the board positions. The board will review progress and discuss further appointments and elected po-

sitions at the board’s next quarterly meeting.

In addition, the board members had an initial discussion about amend-ing the bylaws to make the lengths of board members’ terms as equal as pos-sible.

Doug Faulkner appointed Amber Carver the new Chairperson of the Awards and Nominations committee. Chris Owens, outgoing Chairperson, will assist Amber in the transition.

The board discussed other non-official positions necessary for the smooth functioning of the organiza-tion and that may require specialized knowledge and expertise. Board mem-bers will be looking for possible candi-dates for these committees.

Committee ReportsColorado Birds Editor Scott Gilli-

han had previously submitted a report on the progress of the Fall edition of the journal publication to each mem-ber of the board. The urgent need is to fill the position of Photo Editor. With-out a competent volunteer the photo numbers in subsequent editions will be limited.

Chairperson Lisa Edwards sent the membership report to each board member. Lisa is also responsible for the distribution of the journal and is, therefore, taking on the responsibility for the archived copies. The board ap-proved Lisa’s recommendation to sep-arate the archives into two different locations for security from loss due to any catastrophe that may be possible.

Publicity Chairperson Ted Floyd


has continued supplying and posting information for distribution to CFO’s listserv, website, and social media ven-ues.

Projects and Scholarships Chair-person Christy Carello will be submit-ting information to the board when applications are submitted closer to the deadlines. The board discussed how the established deadlines have an impact on the budget and the deci-sions we make concerning what proj-ects to fund.

Christian Nunes, Chairperson for Social Media, reported on CFO social media communications. Facebook has proven to be a very popular format, with 1,656 members. It is running well and is accessed often.

The Awards and Nominations committee has no report at this time since the responsibilities transferred to a new chairperson at this meeting.

Doug Faulkner reported that quar-terly field trips led by Bill Kaempfer, Ted Floyd, and Nick Komar went very well.

Colorado Bird Records Commit-tee: Chairperson Mark Peterson sent a report that the committee is making good progress reviewing backlogged reports records through 2014 are now caught up and the records for 2015 will be finished soon.. The committee has at the same time been keeping up with the current year’s submissions.

The next CFO Board of Directors meeting will be held on 3 December 2016 at the Denver Museum of Na-ture and Science at 11:00 a.m.

President Faulkner adjourned the meeting at 5:15 p.m.

Respectfully submitted,Chris OwensSecretary to the Board of Directors


Samuel Washington Woodhouse (1821–1904)Bob Righter

Samuel Woodhouse was born in Philadelphia, Pennsylvania. At an early age he decided to become a farmer and began his new en-terprise in Chester County, Pennsylvania. After working the fields for a while, he became more and more fascinated with the birds that were flitting around in between the furrows than he was in plowing the fields. To feed his fascination, he learned taxi-dermy in his spare time, becoming quite skilled at it. He quit farming and one day found himself nosing around Sansom and Twelfth Streets in Phila-delphia where the Academy of Natu-ral Sciences was housed. Here he got to meet and mingle with some of the great ornithologists of the day—John K. Townsend, Thomas Nuttall, Wil-liam Gambel, and John Cassin, among others. That did it, he was hooked, but he also realized shuffling bird skins around in specimen trays was not going to pay a living wage, so he enrolled in medical school and in 1847 graduated from the University of Pennsylvania as a physician. Now he had the tools to make him an attractive candidate for one of the Pacific Railroad Surveys, where he could hone his skills as an naturalist during his travels.

With the recent invention of the steam engine, Congress in the early 1850s became serious about settling on a new Pacific Rail-road route from the Mississippi River to the Pacific Ocean. Three broad westerly routes were up for consideration: a northern route, a middle route, and a southern route. To determine which of these routes would be the most practical and economical, surveys were sent along each to ascertain which had the best potential for the laying of railroad tracks. Colonel John James Abert of the Topographical Engineers (Note 1) asked the Philadelphia Academy of Natural Sciences if they could recommend any physicians willing to also be naturalists that for a boundary survey into Indian Territory. Shortly after, Woodhouse reported to Washington, D.C., and traveled west


in early summer of 1849 to Santa Fe, New Mexico. From there the expedition would start, under the command of First Lieutenant Lo-renzo Sitgreaves (Note 2). Woodhouse was about to experience new adventures he would never forget.

The route to Santa Fe included a stopover in San Antonio, Texas. On 25 April 1851, on prairies near San Antonio, Woodhouse col-lected a sparrow he thought was a Savannah Sparrow. Later, upon his return to Philadelphia, Woodhouse named the new sparrow Cas-sin’s Sparrow, in honor of John Cassin, the noted ornithologist at the Academy of Natural Sciences.

At a location about 200 miles west of San Antonio, near the San Pedro River, on the road to El Paso, in some cedars, Woodhouse col-lected two male vireos that later became the type specimens for the Black-capped Vireo.

On 15 August 1851 the expedition began. Stigreaves’ orders were to explore the area from the Zuni River to the Little Colorado River in northwestern New Mexico and northern Arizona, and finish in southern California. The route would travel through ancient pueblos of the Anasazi, for example Canyon de Chelly and Chaco Canyon, which feature some of the most picturesque canyons and stunning sandstone formations in the West. The area was also known to be a spiritual center for the Navajo Nations. At the time this area was one the least-known parts of the United States. Just before heading west from the Zuni River on 1 September, something on the ground caught Woodhouse’s eye. He bent down to investigate and instanta-neously the fangs of a rattlesnake punctured the skin of his hand. The pain was so intense that he lost the ability to fully use his hand for months. As bad luck would have it, several weeks later as the expedi-tion was approaching the Colorado River, Woodhouse, while sitting near a campfire enjoying the early morning sun, was shot through the leg with an arrow from the bow of a Yavapai Indian brave. Even though Woodhouse was physically compromised, it did not stop him from exploring and collecting natural history items.

As the expedition passed by Inscription Rock, New Mexico, currently within the boundaries of El Morro National Monument, Woodhouse noted some dark and white–colored swifts flying around the rock formation, entering crevices within the rocks. Not having full use of his arm he was unable to collect one of these fast-flying swifts; however, he made meticulous notes describing in detail every-thing about the swifts, which eventually led to his being credited as the original collector (Note 3).

During the second week of October, while the expedition was near the San Francisco Mountains near present day Flagstaff, Arizona, in


and amongst the pinyon-juniper trees, Woodhouse collected a new jay, which became known at the time as Woodhouse’s Jay. In 1995, due to a taxonomic reshuffle, Woodhouse’s Jay was demoted to a sub-species of the Western Scrub-Jay. In July 2016, after careful revision of the “scrub-jay” taxonomic complex by the American Ornitholo-gists’ Union, the jay became known as Woodhouse’s Scrub-Jay.

When the expedition came to the Grand Canyon in early Octo-ber, Stigreaves peered over the edge and quickly summarized there would be no way of crossing a canyon that big and wide and decided the most efficient route west would be to follow the southern eastern edge of the Colorado River. During this leg they were relentlessly attacked by the Yampai, Mohave, and Yuma Indian tribes, and food and water were becoming critically scarce. They finally stumbled into Yuma, Arizona, on 30 November1851, crossed the river and trekked their way to San Diego, California.

Returning from California via Nicaragua to the Philadelphia Academy of Natural Sciences, Woodhouse wrote up the report on the birds and mammals encountered during the expedition. The re-port is contained in Sitgrieves’s Report of the Zuni River Expedition. Woodhouse tried to retire but got caught up in the Civil War. When expeditions and wars finally settled down in 1872, he married and had two children. He died in Philadelphia on 23 October 1904 after living a long and rich life. (See Note 4.)

Note 1Colonel John James Abert was recognized by having the Abert’s

squirrel named in his honor.

Note 2Sitgreaves is remembered today by having a National Forest and

a 9,388-foot peak south of the Grand Canyon named in his honor.

Note 3Upon receiving the specimen of Woodhouse’s black and white

swift, Spencer Baird of the Smithsonian Museum correctly did not accept Woodhouse’s notes as confirmation of a new species because the documentation lacked a specimen. Later in 1854 a specimen of the White-throated Swift was collected by naturalists Caleb Kenne-rly and Baldwin Mollhausen, about 300 miles farther west from In-scription Rock. A specimen they collected became the type specimen for the White-throated Swift. In 1872, while camping at Inscription Rock, Elliot Coues collected some White-throated Swifts. Remem-bering Woodhouse’s original written description of the swifts, Coues


changed the type location of Molhausen and Kennerly’s swift and in-stead credited Woodhouse with the swift’s original discovery and its type location, Inscription Rock. Coues was one of the three founding members of the American Ornithologists’ Union as well as author of many definitive books about bird identification and distribution. Among his peers he held considerable sway in how things should or should not be.

Note 4Mammals and other birds named by Woodhouse include the des-

ert pocket mouse, Ord’s kangaroo rat, fulvous pocket gopher, Abert’s Towhee, and the “Gray-headed Junco,” which is now a common sub-species of the Dark-eyed Junco. This form is the commonest junco in the mountains of Colorado during the summer.

LITERATURE CITEDCoues, E. 1874. Birds of the Northwest. Government Printing Office, Washington, DC.Fischer, D. L. 2001. Early Southwest Ornithologists 1528–1900. University of Arizona

Press, Tucson.Goetzmann, W. H., and G. Williams. 1992. The Atlas of North American Exploration.

University of Oklahoma Press, Norman.Hume, E. E. 1942. Ornithologists of the United States Army Medical Corps. Johns Hop-

kins University Press, Baltimore, MD.https://en.wikipedia.org/wiki/Pacific_Railroad_Surveyshttps://en.wikipedia.org/wiki/Yavapai

Bob Righter, [email protected]


First Colorado Record of Couch’s Kingbird (Tyrannus couchii)Dave Leatherman

BackgroundOn 19 April 2016 I met Dick Filby’s sleepy-eyed grouse tour group

in Lamar, Colorado, at 9:50 a.m. for their civilized-hour-of-the-day visit to the Community College Woods. After finding whatever we could (a couple of “northerners”—cardinal and parula—were the highlights), I had intended to drive 4+ hours north to my residence in Fort Collins. However, a report of rare shorebirds at Lake Hol-brook easily influenced a postponement of this return to the Front Range for one more day. While waiting for my friend Janeal Thomp-son’s return from early-morning business and a try for the shorebirds, I decided to visit Riverside Cemetery off Maple Street in northern Lamar (Prowers County). That proved to be a lucky choice.

Observation Details and Bird DescriptionUpon my arrival at the cemetery around 11 a.m., the main me-

morial area was relatively devoid of small passerines, particularly migrants. I decided to check the weedy, sparsely wooded fence line that runs north–south from the northwestern corner of the cemetery north a hundred meters or so to the Lamar Canal.

This narrow interface between an open alfalfa field to the east and a vacant strip abutting an industrial park to the west has produced interesting birds in the past such as Red-headed Woodpecker, Win-ter Wren, Nashville Warbler, White-throated Sparrow, Swamp Spar-row, Harris’s Sparrow, and Field Sparrow. Scattered trees in this area include plains cottonwood (Populus deltoides), Siberian elm (Ulmus pumila), and Rocky Mountain juniper (Juniperus occidentalis). In the waste areas and along the fence line, key non-woody plants include giant ragweed (Ambrosia trifida var. trifida), horsetail milkweed (As-clepius subverticillata), pigweed (Amaranthus sp.), and wild sunflower (Helianthus annuus). From a bird feeding standpoint, these two sets of plants are complemented by the cultivated alfalfa (Medicago sativa). The Lamar Canal and an associated minor irrigation ditch/ditch bank that runs south and east along the north edge of the cemetery support a thriving population of wetland-habitat life capable of withstanding poor water quality. Associated life forms of potential value to birds are Physa snails; freshwater clams; leopard frogs; rubyspot damselfly and other odonates such as blue-eyed darner, common green darner,


variegated meadowhawk, common bluet species, and others; field crickets (abundant), many grasshopper species, many other insects; and other arthropods.

Just south of the canal I had a small female oriole working its way northward. Analysis of quickly snapped photos showed it to be an Orchard Oriole (Icterus spurius), perhaps one of the earliest on record for Colorado. Still excited by this bird, my attention was soon di-verted to a yellow-bellied kingbird, also flying northward. I assumed it was an early Western Kingbird (Tyrannus verticalis), but because it was my first kingbird of any kind in Colorado in 2016, I kept observ-ing it. As it landed in a juniper along the canal, I noticed the tail was solid brown and the outer rectrices were not white. Switching scru-tiny to the head, it showed as mostly gray with a subdued mask. This was nothing like the expected other common yellow-bellied kingbird without a white outer tail in Colorado, namely Cassin’s (T. vocifer-ans), which has a dark head and strongly contrasting whitish throat. My interest soared, as it now became apparent this kingbird might be a Tropical/Couch’s type, neither of which had been recorded previ-ously in Colorado.

What to do? Try for photographs or carefully observe the bird? I tried to slowly move closer while doing both.

The yellow hue of the breast and belly was bright lemon yellow, extending almost up to the throat. This hue changed depending on light conditions, being predominately yellow in good light, greenish yellow in poor light. As stated, the upper breast was strikingly not gray, as in most all Westerns. The head was rounded and gray with a slightly darker “mask” extending from the base of the bill through the eye to the rear of the head. The all-black bill was a bit longer than a typical Western and thicker at its base. The upper mandible (cul-men) was curved, and its tip was slightly hooked (not visible from a distance). The throat, malar, and auricular areas below the mask were light gray (much paler than the crown, but not bright white). The yellow-green of the upper breast extended around the side of the neck toward the back. The back was gray with a tinge of green, but was neither bright green nor as green as a typical Tropical/Couch’s. The scapulars and wing coverts were gray-brown, with the secondar-ies and primaries being mostly medium brown with white edges. The bird had broken wingbars but they were not at all conspicuous. The tail was slightly notched, mostly blackish underneath with all rectri-ces showing pale tips. I could not tell if this paleness was due to an actual difference in color from the rest of the feathers or just wear. The legs were dark gray-black.

The bird only made a few short, single-syllable vocalizations,


Fig. 1. Couch’s Kingbird in juniper along Lamar Canal/Colonia Avenue east of Main Street in Lamar on 19 April 2016, showing extent of yel-low on upper breast, greenish-gray back, brown wings, and lack of white outer tail feathers. Photo by David Leatherman

Fig. 2. This photo emphasizes bright yellow-green underparts, lack of white in outer rectrices, pale facial mask, and thick base of bill. Photo by David Leatherman

Fig. 3. Couch’s Kingbird—highly cropped view of head showing rounded crown; big bill with curved culmen, hooked upper mandible tip, longish length (compared with Western Kingbird), and thick base; pale mask; yel-low underparts extending up to the throat and somewhat wrapping over shoulder to side of mantle; gray back with hint of green, but not as green as most Couch’s Kingbirds. Photo by David Leatherman


which to my ear were a simple kip or kit, not unlike a common utter-ance of Western Kingbird. While hardly seeming important at the time, taking note of these calls was helpful to the ultimate identifica-tion.

As for behavior, when not flying this kingbird seemed very restless and only stayed on any one perch for a short period. I only saw it land in perhaps four of the planted, large, berry-laden Rocky Mountain ju-nipers. I did not see it eat any fruit, which many large flycatchers are known to do on migration, but I did get poor looks at it quickly con-suming a large dragonfly, most likely a common green darner (Anax junius).

About 10 minutes into this encounter, the bird flew to a big juni-per on the north side of the Lamar Canal. Still wanting better looks and photographs, I, too, crossed a truck road over to the paved street on that side (Colonia Avenue). For whatever reason (it did not ap-pear to be my approach), the bird flew back toward junipers on the south side of the ditch, behind one of them, and I never saw it again. This was all very exciting, to be sure, but certainly not satisfying. My estimation of how long the entire episode lasted is only 15 minutes.

I met Janeal at her Lamar home and we pored over field guides and online images of all North American yellow-bellied kingbirds. It seemed clear the Lamar bird was a Tropical/Couch’s, with Couch’s best fitting my memory and photos. We returned to the site in early afternoon but unfortunately did not refind the kingbird.

Summary of Record AnalysisThe most important field marks to both the Colorado Bird Records

Committee members and the outside reviewers from Texas in ac-cepting/favoring, respectively, an identification of Tropical/Couch’s Kingbird and not a Western were: bill shape and size (slightly lon-ger); extent of yellow on the upper breast (and corresponding lack of gray in this area); tail color (brown with an absence of white outer rectrices) and shape (slight notch). Clinchers to almost all reviewers in terms of it being Couch’s and not Tropical were: upper mandible curvature and wide bill base; shallow vs. deep depth of tail notch; and the description of vocalizations (simple kip). I was bothered some-what by the lack of strong green tones in the back, but experienced reviewers indicated that this bird, while not as green-backed as is typical, was within the range of Couch’s.

Even in parts of the southern range of Couch’s where it occurs commonly with Tropical, hybrids are virtually unknown. Thus, re-viewers felt the prospect of this bird being a Tropical × Couch’s as highly unlikely. Crosses with Western and Tropical/Couch’s birds are


not common but more likely than Tropical × Couch’s. One Texas reviewer remarked that this bird did not exhibit characteristics sug-gestive of having Western Kingbird genes.

In areas where Couch’s is known to exhibit migratory movements, it shows up a few weeks earlier than Western, consistent with the Colorado bird being a bit earlier than we typically start seeing West-erns show up in the southern part of the state (Brush 1999).

Historical Background and Discussionof Extralimital US Records

Couch’s Kingbird was first discovered by Lieutenant Darius N. Couch near San Diego, Nuevo Leon, Mexico, in 1853. It was for-mally described in 1859 as a distinct species, only to be reclassified 15 years later as a subspecies of Tropical Kingbird (T. melancholicus) (Baird 1859, Coues 1873). Many decades later, a study by Smith of kingbird vocalizations and behavior led to its reclassification as a valid species (Coues 1873, Smith 1966, Traylor 1979).

The Couch’s Kingbird range extends from Texas south along the eastern coastal plain of Mexico, including all of the Yucatan Pen-insula, south to northern Guatemala and southern Belize (Conant 1968, Brush 1999). Like many southern species under the influence of climate change, its range appears to be expanding northward. Cur-rently, the available eBird map shows it as expected in the United States in southern Texas roughly below a line from Houston north-west to Austin southwest to Del Rio (Brush 1999).

This same eBird map shows outlying records in Massachusetts, New York, Pennsylvania, Michigan, Florida, Alabama, Mississippi, Louisiana, Arkansas, Nebraska, New Mexico, Arizona, Nevada, and California. In the eBird database, the closest extralimital occurrences to Lamar and their respective dates of occurrence are: Boone’s Draw near Portales, New Mexico, on 21 May 2016 (320 miles); Tahoka Lake, Texas, on 29 September 2016 (366 miles); Close City, Texas, on 22 September 2016 (373 miles); Valley, Nebraska, northwest of Omaha on 25 July 2015 (514 miles); Fontenelle Forest, Nebraska, south of Omaha on 9 May 2015 (522 miles); Doña Ana, New Mex-ico, on 14 October 2011 (602 miles); and Cliff, New Mexico, on14 March 1998 (650 miles). If one draws a mild arc from the sightings in eastern Nebraska (which may well represent the same individual) to the northeastern New Mexico site, southeastern Colorado falls roughly in line with that degree of northwesterly extension (eBird 2016).

Expanding on the last paragraph a bit, while mostly resident within its range, some migratory movements by Couch’s Kingbirds


occur near the edges. As such, it seems plausible, if not likely, that a northward spring migrant on a vector moving up the eastern flank of Mexico could end up in southeastern Colorado assisted by wind and a somewhat flawed internal “braking” system. Note the early and/or unusual co-occurrence in the Lamar area just before and after the Couch’s Kingbird of other species normally residing or wintering to the south and east of Colorado such as Orchard Oriole, Northern Pa-rula, Hudsonian Godwit, Glossy Ibis, Little Blue Heron, and Brown Pelican. Devotees of chaos theory would say, “Maybe not.” Who knows about such things?

Because much of its existence since initial discovery in the mid-1800s has been spent in relative and invalid obscurity as a subspe-cies of the more widespread Tropical Kingbird, not many specifics are known about its biology (Brush 1999). Since many flycatchers, especially the larger tyrant species, are known to feed on odonates, it is not surprising this Couch’s Kingbird ate a darner. At least this life history anecdote can be added. All reported fruits eaten by Couch’s Kingbird are from non-coniferous plants (Brush 1999). Even so, and despite my not observing this, it seems likely juniper berries could have been part of this individual’s diet while in Colorado.

As of this observation’s date, the Official List of Colorado bird species stood at 499. In the Winter 2016 issue (vol. 50 no. 1) of Colo-rado Birds editor Peter Burke coordinated an article in which selected Colorado bird experts were put on the spot to speculate about which species would be #500. The responses were all erudite and included no less than 67 likely candidate species. One soothsayer who was also the finder of #499 (Vaux’s Swift), Brandon Percival of Pueblo, mentioned Couch’s Kingbird (Burke 2016).

Colorado’s already impressive list will assuredly grow, and probably include many of the other 66 species mentioned in that article. One of them, Brown Booby, has already incredibly appeared in our midst. Splits are imminent. Exotic establishments are lengthening. Skilled sleuths are out there at this moment beating the bushes. Birds still have wings. Will the state list ever reach 600? In truth I hope not, because that would probably mean many of our beloved high-altitude taxa like White-tailed Ptarmigan, Pine Grosbeak, and White-winged Crossbill are mere memories.

May we all do what we can—one interpersonal interaction, one classroom, one field trip, one work assignment, one vote, one ex-ample, one bird encounter at a time—to protect Colorado’s birds.

ACkNOWLEDgmENTsI thank the Colorado Birds Records Committee for their work on behalf of the birding


community in Colorado. Specifically I appreciate Mark Peterson for helping me over-come password issues and other glitches I seem to attract within the electronic record submission process, and the committee members for their time and expertise in consider-ation of this record. That they went to the effort of circulating photos to the Texas Bird Records Committee, whose members have considerably more experience with this and similar species than most of us in Colorado, says a lot about our committee’s attention to detail. Of course, I am pleased the record was accepted, but in the grand scheme am not heartened by the reasons it probably showed up so out of place. It also merits stating we are fortunate in Colorado to have a system of careful records scrutiny. Perhaps in the future this thankless task and arguably somewhat duplicative process will be absorbed by the equally thankless but solid vetting system underpinning the vast eBird database. Until a new scheme evolves for quality control of our bird records, the CBRC is certainly deserving of our continued support.

LITERATURE CITED Baird, S. F. 1859. Birds of the boundary. In Report on the United States and Mexican

Boundary Survey. Part 2. Zoology of the Boundary (W. H. Emory, editor). C. Wen-dell, Washington, DC. pp. 1–32.

Brush, T. 1999. Couch’s Kingbird (Tyrannus couchii). In The Birds of North America On-line (P. G. Rodewald, Editor). Cornell Lab of Ornithology, Ithaca, NY. doi:10.2173/bna.437

Burke, P. 2016. The race is on! Who will identify Colorado’s 500th Species of bird? Colorado Birds 50:305–316.

Conant, R. 1968. Zoological exploration in Mexico—The route of Lieut. D.N. Couch in 1853. American Museum Novitates No. 2350, Washington, DC.

Coues, E. 1873. Checklist of North American Birds, 1st ed. American Ornithologists’ Union, Washington, DC.

eBird. 2016. eBird: An online database of bird distribution and abundance. eBird, Itha-ca, NY. Available at http://www.ebird.org.

Sennett, G. B. 1878. Notes on the ornithology of the Lower Rio Grande of Texas from observations made during the season of 1877. Bulletin of the United States Geologic and Geographic Survey of the Territories 4(1):1–66.

Smith, W. J. 1966. Communication and relationships in the genus Tyrannus. Publica-tions of the Nuttall Ornithological Club 6:1–250.

Traylor, M. A., Jr. 1979. Two sibling species of Tyrannus (Tyrannidae). The Auk 96:221–233.

Dave Leatherman, Fort Collins, [email protected]


The Effects of Flooding on the Avian Community of Chatfield State ParkFrancis CommerçonAbstract

The Chatfield Reallocation project will periodically inundate many acres of riparian forest in Chatfield State Park. I conducted surveys over floodwaters from natural precipitation events in May and June of 2015 to determine the responses of avian communities to flooding. Results could provide insight into how periodic flooding will impact bird communities during years of high water in Chatfield State Park. A general trend exists for birds to be less common per unit area in flooded forests compared to non-flooded forests. Two species, Lesser Goldfinch and Brown-headed Cowbird, showed significantly lower densities in flooded forests. Possible explanations for these patterns could include the effect of floodwaters on nesting habitat and forage availability for some species. Differences were small and mostly nonsignificant, meaning that flooded forests still do provide important habitat for birds, though not exactly the same species and not in the same densities as in non-flooded forests.

IntroductionWhen our society develops surface water resources, we have sig-

nificant impacts on terrestrial and aquatic wildlife associated with riparian ecosystems. In anticipation of increases in residential and commercial development along the Colorado Front Range, water providers have developed projects to augment water supplies for the future, including increased surface storage.

One such project is the Chatfield Reallocation Project by the Army Corps of Engineers and several metro-area providers southwest of Denver. This project will store the peak flows along the South Platte River by raising the Chatfield Reservoir’s water level during high runoff years. Water levels will only fill the new area available for storage periodically. This occasional increase in water level will, for boater safety reasons, require clearing of much forest around the lake. However, the Army Corps’ “Tree Management Plan (Appendix Z of the Final Environmental Impact Statement; see Chatfield Reservoir Reallocation Participants 2014) states that as much as 61.1 acres of cottonwood forest will be left standing in the potential inundation zone around Chatfield Reservoir. This means that a portion of the park’s wildlife habitat will occasionally be under up to five feet of wa-ter. Project documents also state that additional areas of forest should


be spared from clear cutting given that Colorado Parks and Wildlife (CPW) does not find them to be especially vulnerable to death from inundation (Chatfield Reservoir Reallocation Project Participants 2014).

I investigated how different bird species in the park would respond to such inundation. Heavy rains in April and May of 2015 and fast snowmelt in June caused the South Platte to swell, and the Corps of Engineers backed up the excess water in Chatfield Reservoir to protect downstream Denver from flooding. Water levels in the res-ervoir rose nine feet above the normal conservation pool level by late May. This led to significant inundation of the forests along the edges of the reservoir and near the mouths of the South Platte River and Plum Creek. This natural flooding replicated the conditions one would expect under the Chatfield Reallocation project if the Corps left all forests standing. Much of the forest further upstream remained unflooded, and a survey of birds in the unflooded forests allowed me to compare the flooded forest avian community to what it could be during unflooded years.

Both Plum Creek and the South Platte River flow into Chatfield Reservoir, and extensive riparian forests grow at the mouths of these two rivers and along their lengths. The forest along the South Platte consists predominantly of Great Plains cottonwood, with significant presence of boxelder, narrow-leaf cottonwood, and peach-leafed wil-low. The forest community along Plum Creek has a much greater percentage of willow. The understory of both forests contains young trees and a great diversity of shrubs, most notably common choke-cherry, wild plum, and sandbar willow (see Fig. 1).

This study reveals how the avian community might change dur-ing flood years during the Chatfield Reallocation Project in the forest that is left uncleared. I expected that overall avian diversity would be lower under flood conditions because only those species charac-teristic of the upper canopy or those with great flexibility in habitat requirements could make use of the flooded habitat.

MethodsI established two transects each of flooded forest and non-flooded

forest to use for my comparisons (see Fig. 1). Using CPW estimates of water depth and the elevation tool on Google Earth, I remotely determined the perimeters of the flooded area of the forests both at the mouth of Plum Creek and at the mouth of the South Platte. I established the perimeters of unflooded transects by hiking the pe-rimeters of every potential unflooded forest with a GPS to track my movements.


Fig. 1. Study area: center picture is Chatfield State Park, upper left picture shows transect along the South Platte River, and lower right picture shows transects along Plum Creek.

I created a spatially balanced random sample of points within each study transect, selecting randomly generated points within 20 me-ters of significant forest cover, and points that were no less than 150 meters from any other point to ensure independence of surveys. I surveyed at 37 points (FW 11 points, FE 10 points, DW 9 points, and DE 7 points; see Fig. 1), accessing the flooded points by open-water kayak.

At each point, I conducted avian point counts and basic vegeta-tion surveys. I followed the Integrated Monitoring for Bird Conserva-tion Regions protocol (Hanni et al. 2015) with slight modifications. I recorded each bird detection over an eight-minute period. I used a rangefinder to estimate distances of each detection, recorded in me-ters. Transects started at 6:27 a.m. on average. I continued until no later than 5.5 hours after sunrise to avoid biases from decreasing bird activity.

I characterized the habitat within a 50-m radius circle around each point. I estimated canopy height, overall percent canopy cover, canopy cover by dominant tree species, and extent of understory


Species code Species name FE FW DW DE Total

YEWA Yellow Warbler 47 48 49 30 174

HOWR House Wren 29 20 36 32 117

LEGO Lesser Goldfinch 5 6 10 11 32

BHCO Brown-headed Cowbird 6 7 10 8 31

WEWP Western Wood-Pewee 11 6 6 5 28

AMRO American Robin 7 6 7 6 26

YBCH Yellow-breasted Chat 0 3 11 5 19

RWBL Red-winged Blackbird 3 0 12 4 19

MALL Mallard 12 5 0 1 18

NOFL Northern Flicker 2 1 5 5 13

WAVI Warbling Vireo 2 5 5 0 12

MODO Mourning Dove 2 2 2 6 12

DOWO Downy Woodpecker 4 1 3 4 12

GRCA Gray Catbird 2 1 3 5 11

SOSP Song Sparrow 0 0 2 8 10

BCCH Black-capped Chickadee 4 4 0 1 9

Table 1. Detection frequencies in each transect (FE, FW, DW, DE) of each species for which I estimated density.

shrubs (presented as “Shrub Cover” or mean understory height times estimated percent understory cover). I conducted linear regressions in program R (version 3.2.1) between these habitat variables and 15 bird species to elucidate habitat preferences. I ran regressions within habitat types so differences between flooded and non-flooded forests would not influence correlations between species and habitat charac-teristics. I also conducted ANOVA tests to determine whether these habitat characteristics varied between habitat types.

I calculated densities of 16 of the most common bird species in my data. I used the software Distance 6.2 to estimate density for each of the species in Table 1. For each species and habitat type (flooded or non-flooded), I ran several models of how detection varies with dis-tance. I tested models based solely on radial distance measurements and models using seven possible combinations of three covariates: canopy cover, shrub cover, and time of day. In the models I ran com-binations of key functions and series expansions suggested in Buck-land et al. (1993). I used AIC to select the most appropriate model for each species for each habitat type. The software used the modeled detection function to calculate a density in birds/hectare and a 95%


confidence interval for that density estimate.

ResultsTable 1 shows the species analyzed

and the frequency of detection from each transect. I recorded 756 bird de-tections representing 49 species.

There was an overall trend for birds to have lower densities in flooded forests (Table 2), however most dif-ferences were small and the majority were statistically insignificant (Fig. 2). Fig. 3 shows the actual density esti-mates and confidence intervals in each habitat type for each species analyzed. The only species for which densities in flooded forests were higher than in non-flooded forests was American Robin. I detected more Black-capped Chickadees and Mallards in flooded forests, but data were insufficient to es-timate densities in non-flooded forests for reliable comparison. Song Spar-

rows had ten detections in the un-flooded forests and zero detections in the flooded forests.

The most abundant species were Yellow Warbler, with a density of 14.12 birds per hectare in the non-flooded forests, and House Wrens, with a density of 13.05 birds per hectare in non-flooded forests. Small sample sizes for many other species led to very large uncertainty in de-tection function modeling and thus uncertainty in density estimates, as shown by the error bars in Fig. 2. Future studies should resample points multiple times to increase sample size. Despite the wide con-fidence intervals, Lesser Goldfinches and Brown-headed Cowbirds both showed significantly higher densities in unflooded transects (see Table 3 and Figs. 1 and 2)

ANOVA tests of habitat characteristics between habitat types showed that flooded forests had significantly lower shrub cover, more Great Plains cottonwood, and less narrow-leaf cottonwood (Table 4). Table 3 shows all correlations between species and habitat variables. Flickers showed an association with Plains Cottonwood, perhaps explaining why this species did not decline significantly in flooded transects where plains cottonwood is more abundant. Wrens, vireos,

Species Flooded Non-flooded

YEWA 9.02 14.12

HOWR 6.38 13.05

LEGO 0.54 6.16

BHCO 0.91 3.79

BCCH 2.83 no estimate

YBCH 0.34 1.81

WEWP 0.67 0.73

AMRO 0.81 0.46

DOWO 0.48 1.51

SOSP no estimate 0.35

GRCA 0.24 1.02

RWBL 0.33 0.57

MALL 1.67 no estimate

WAVI 0.2 0.45

MODO 0.11 0.28

NOFL 0.08 0.35

Table 2. Density estimates (birds/ha) for flooded and non-flooded habitat types.


Fig. 3. Density estimates (birds/ha) for all 16 species analyzed including those with sufficient data only for one habitat type. Error bars represent 95% confi-dence intervals.

Fig. 2. Bars represent the density of each species in the flooded transect minus the density estimate from the non-flooded transect. Negative values indicate lower densities in flooded forests. Gray bars indicate statistical significance (P < 0.05). The graph includes only species for which density estimates for both habitat types could be estimated.


and pewees showed a positive association with greater canopy cover, which may also help explain their nonsignificant change in flooded transects, which had more continuous and extensive forest cover (see Fig. 1).

Interestingly, Lesser Goldfinches were the only birds to show any significant correlation with shrub cover, and it was a negative corre-lation despite common knowledge that these birds prefer to forage on herbaceous ground cover and understory plants (Watt et al. 2014). This pattern may indicate that elimination of the understory does not explain significantly lower densities of goldfinches in flooded forests. However, it may also reveal that such correlations do not reflect actual habitat associations (see Discussion). Vireos and pe-wees both show positive correlations with narrow-leaf cottonwood,

Species Habitat variable Direction P value Adjusted r-squared Forest type

BCCH willow positive 0.04038 0.2147 non-flooded

BHCO plains cottonwood negative 0.03753 0.1754 flooded

HOWR canopy positive 0.007694 0.2962 flooded

HOWR plains cottonwood positive 0.00424 0.3386 flooded

LEGO height positive 0.03126 0.19 flooded

LEGO shrub cover negative 0.04026 0.215 non-flooded

NOFL height positive 0.005972 0.3143 flooded

NOFL Boxelder positive 0.01761 0.2347 flooded

NOFL plains cottonwood positive 0.0002475 0.6024 non-flooded

SOSP canopy negative 0.04422 0.2058 non-flooded

WAVI narrow-leaf cottonwood positive 0.02737 0.2524 non-flooded

WAVI canopy positive 0.02442 0.2632 non-flooded

WAVI height positive 0.001066 0.5142 non-flooded

WEWP canopy positive 0.01034 0.341 non-flooded

WEWP narrow-leaf cottonwood positive 0.01758 0.2938 non-flooded

YBCH boxelder positive 0.001393 0.4106 flooded

YEWA height positive 0.007064 0.3733 non-flooded

Table 3. Linear regressions between species abundance and habitat characteristics. Bolded relationships are those with habitat variables that vary significantly between flooded and non-flooded habitat types (see Table 3). A “positive” direction indicates species abundance increased as the habitat variable increased. P < 0.05 indicates sig-nificance. Note, however, that r-squared values show the percent of variation in spe-cies abundance actually explained by a linear relationship with the habitat variable. “Forest Type” denotes the habitat types in which the relationship was found.


which is significantly more abundant in non-flooded areas. Yet these species still persist in comparable densities in flooded transects.

DiscussionComparing avian communities

between flooded and non-flooded for-ests should reveal the ecological sig-nificance of the understory stratum of vegetation. Flooded transects lacked herbaceous vegetation, such as grasses and forbs, and dense thickets of woody shrubs. This key difference in vegetation would seem to impact the quality of the habitat for dif-ferent bird species by affecting forage availability and nest site avail-ability. However, only one species in this study showed a significant correlation with understory cover.

The only two species with statistically significant differences in density both showed lower densities in flooded forests. Lesser Gold-finches are primarily seed-eating birds, preferring to forage near the ground on seed-bearing herbaceous plants and woody shrubs and trees (Watt et al. 2014). And although goldfinches do consume buds of cottonwoods, the canopies of the flooded transects, comprised pri-marily of cottonwoods, willows, and boxelder, likely do not provide nearly the abundance of seeds found in non-flooded areas with seed-bearing forbs (e.g., thistles). Although I was unable to analyze many seed specialists other than Lesser Goldfinches, I suspect that granivo-rous birds in general were more severely affected by the flooding than insectivorous birds.

Brown-headed Cowbirds, on the other hand, are more generalist in diet, and it is not readily apparent why such a difference would be seen for this species. An alternative explanation for their appar-ent preference for non-flooded areas is simply that non-flooded tran-sects inherently contain better habitat for Brown-headed Cowbirds regardless of flood conditions. This species prefers forest edges and a mix of forest and open field (Lowther 1993). Because they were located upstream, my non-flooded transects were in fact long, thin expanses of forest along rivers, with much more edge habitat than the continuous swaths of forest found in the river deltas in the flooded transects (see Fig. 1). Therefore, the pattern seen with Brown-headed Cowbirds may in fact be due to a confounding variable that I was un-able to take into consideration.

A closer look at the species with non-significant differences con-

Habitat variable Direction

shrub cover non-flooded

plains cottonwood flooded

narrow-leaf cottonwood non-flooded

Table 4. Habitat characteristics that varied significantly between flooded and non-flooded transects. “Direction” de-notes the habitat type in which the habi-tat variable was significantly higher.


firms a trend for birds to have lower densities in the flooded forests. For species such as Gray Catbird and Yellow-breasted Chat, which nest in dense thickets and bushes often not far from the ground, flooding likely eliminates nesting habitat (Eckerle et al 2001, Smith et al 2011). Yellow Warblers and House Wrens had higher densities in non-flooded forests but still maintained very substantial densities in the flooded forests. This may be due to level of forage availability. Eliminating the understory eliminates a huge portion of the substrate from which these insectivorous gleaners can obtain food. Flooded forests therefore may provide enough food only to support lower den-sities of birds than seen in normal riparian forests.

The differences between densities are relatively small for most species, and all but two were statistically nonsignificant. This indi-cates that flooded forests do provide benefits to riparian forest birds, particularly insectivorous species foraging in the canopy. Floodwaters can also provide other services, such as protection from terrestrial nest predators. During surveys over floodwaters I came across two House Wren nests and a Black-capped Chickadee feeding two fledg-lings hundreds of meters from the nearest land.

Furthermore, some species may not be affected positively or nega-tively by flooding. Western Wood-Pewee showed nearly identical density estimates between the two habitat types. This could be be-cause of the species’ foraging strategy, sallying for flying insects, which does not depend on the amount of understory vegetation exposed.

Correlations between birds and habitat variables in the non-flood-ed transects may provide insight into natural habitat requirements that affect how species respond to unnatural flooding. And habitat correlations within the flooded forests can help explain the persis-tence of some species in this habitat, for example the three Yellow-breasted Chats (typically an understory species) that I detected in flooded habitats were strongly associated with submerged boxelder, a very prominent understory tree. However, I must be cautious when making assumptions based on these habitat correlations. These abun-dance–habitat relationships do not always predict the birds’ actual response to flooding, as in the case of Lesser Goldfinches. Very likely, comparing detection frequency with general habitat measurements in the area does not accurately portray the feeding and nesting habi-tat requirements of birds.

ConclusionsThere was a clear trend for birds to be less common per unit area

in flooded forests. These differences are likely due to reduced food availability and/or reduced nest site availability for some birds. How-


ever, small and nonsignificant differences in densities also show that flooded forest provides habitat benefits to support a considerable den-sity of birds. As such, if tree management decisions in the Chatfield Reallocation Project are intended to benefit birds, then there is rea-son to retain forest to be periodically inundated.

ACkNOWLEDgmENTsThank you to Cameron Ghalambor for providing the GPS, rangefinder, and clinometer necessary for this study as well as advising me at points throughout the project. Thank you to Emily Kane for providing the kayak and associated gear. Thank you for Joyce and Pascal Commercon for letting me use their car and supporting me through this intense field season. Thanks to Travis Gallo for helping me learn program Distance. Thank for Amber Carver, Paul Doherty, and all the other great people who helped in big and little ways along the way!

LITERATURE CITEDBuckland, S. T., D. R. Anderson, K. P. Burnham, and J. L. Laake. 1993. Distance Sam-

pling: Estimating Abundance of Biological Populations. Chapman and Hall, London.Chatfield Reservoir Reallocation Project Participants. 2014. Chatfield Reservoir Real-

location Project Fish, Wildlife, and Recreation Mitigation Plan. Unpublished report prepared for Colorado Parks and Wildlife Commission.

Eckerle, K. P., and C. F. Thompson. 2001. Yellow-breasted Chat (Icteria virens) in A. Poole (ed.). The Birds of North America Online. Cornell Lab of Ornithology, Ithaca, NY. doi:10.2173/bna.575

Hanni, D. J., C. M. White, N. J. Van Lanen, J. J. Birek, J. M. Berven, and M. F. McLaren. 2015. Integrated Monitoring in Bird Conservation Regions (IMBCR): Field protocol for spatially balanced sampling of landbird populations. Unpublished report. Rocky Mountain Bird Observatory, Brighton, CO.

Lowther, P. E. 1993. Brown-headed Cowbird (Molothrus ater) in A. Poole (ed.). The Birds of North America Online. Cornell Lab of Ornithology, Ithaca, NY. doi:10.2173/bna.47

Smith, R. J., M. I. Hatch, D. A. Cimprich, and F. R. Moore. 2011. Gray Catbird (Dume-tella carolinensis) in A. Poole (ed.). The Birds of North America Online. Cornell Lab of Ornithology, Ithaca, NY. doi:10.2173/bna.167

Watt, D. J., and E. J. Willoughby. 2014. Lesser Goldfinch (Spinus psaltria) in A. Poole (ed.). The Birds of North America Online. Cornell Lab of Ornithology, Ithaca, NY. doi:10.2173/bna.392

Francis Commerçon, [email protected]


NEWS FROM THE FIELD

Summer 2016 (June–July)David Dowell

“News from the Field” contains reports of rare birds found in Colorado. These reports are compiled from eBird (ebird.org), the COBirds listserv ([email protected]), and the West Slope Birding Network ([email protected]). The reports contained herein are largely unchecked, and the editors do not necessarily vouch for their authenticity. Species in capitals are those for which the Colorado Bird Records Committee (CBRC) requests documen-tation. Please submit your sightings of these “review” species through the CFO website at coloradobirdrecords.org.Season Overview

The biggest “news from the field” is the addition of two new spe-cies to the state list: Couch’s Kingbird (#500) by Dave Leatherman in April and Brown Booby (#501) by Peter Bandurian in June. Couch’s Kingbird is a species that can be easily overlooked because it resem-bles the Western and Cassin’s Kingbirds that are abundant in our state. Dave Leatherman’s careful observation and prior experience with Kingbird varieties helped him find this species in Colorado. Pe-ter Bandurian relied on general outdoor experience, knowing some-thing unusual when he saw it. His decision to stop and take photos of what turned out to be a Brown Booby was a good one. Other articles in this issue will have more information on these birds.

Other rarities were also found in Colorado in summer 2016. West-ern Gull is typically found only in Pacific coastal states. This summer, not one but two Western Gulls visited Colorado, and both stayed for a while. An adult Western Gull in the San Luis Valley, found first on 4 June at Smith Reservoir in Costilla, is probably the same one spot-ted in mid-May in northern New Mexico, as photos show a striking resemblance. A second-cycle Western Gull found at Prewitt Reser-voir in Washington/Logan wore a distinctive white and silvery band, attached in 2015 when the bird was a chick on the Farallon Islands west of San Francisco, California. Another surprise visitor to Pre-witt Reservoir was an immature Thayer’s Gull, a species that is very rare anywhere in the United States other than Alaska in summer. Lesser Black-backed Gulls, found at four Colorado lakes in June and July, continued to establish themselves as regular but still uncommon summer residents in the state.

For the second consecutive summer, a male Pacific Wren filled the air with its distinctive, complicated songs near Calypso Cascades in the Wild Basin section of Rocky Mountain National Park, Boulder.


Further investigation turned up a female and two begging juveniles. This is the first time that a family group of Pacific Wrens, confirmed to have bred locally, has been found in Colorado.

For the third consecutive summer, a group of Baird’s Sparrows was found in Colorado, and this time it was a particularly large group. As many as 20 were seen and heard at the Soapstone Prairie Natural Area in northern Larimer.

Summer 2016 in Colorado will also be remembered for Dickcis-sels—lots of ‘em. This species was reported in 29 counties, often in large numbers. In southern Colorado, Dickcissels were found west of their usual range and at relatively high elevation.

In the list of reports below, county names are italicized, and the fol-lowing abbreviations are used: CFO – Colorado Field Ornithologists; CG – campground; m.ob. – many observers; NA – Natural Area; NHS – National Historic Site; NP – National Park; NRA – National Recreation Area; NWR – National Wildlife Refuge; Res. – Reser-voir; SP – State Park; STL – State Trust Lands; SWA – State Wildlife Area.

Greater White-fronted Goose: 1 at Timnath Res., Larimer, 2 Jun (Tom Thomson, Nick Komar).

Common Goldeneye: As many as 5 at Sands Lake SWA, Chaffee, throughout the summer, ongoing from winter and spring (Jeff Guy, Jon Horn, m.ob.). 2 at Smith Res., Cos-tilla, 25 May–4 Jun (Steven Mlodi-now, Ted Floyd). 1 at Hamilton Res., Larimer, 9–26 Jun (Nick Komar, For-rest Luke, Kathleen Horn, Roger L. Horn). 1 at Lake Maria, Huerfano, 13 Jun (Sue Riffe). 1 at Windy Gap Res., Grand, 9 Jul (group led by Wil-liam Kaempfer). 1 at Walden Res., Jackson, 23 Jul (Steven Mlodinow, David Dowell).

Barrow’s Goldeneye: 1 at Ham-ilton Res., Larimer, 8 June (David Leatherman). 5 at Hohnholz Lakes SWA, Larimer, 25 Jun–24 Jul (Da-vid Wade, Nick Komar, m.ob.). Other reports from Clear Creek,

Garfield, Grand, and Rio Blanco, 1 Jun–31 Jul.

Hooded Merganser: 1 female at San Luis Lakes SP, Alamosa, 20 Jun (John Rawinski); first summer record for San Luis Valley.

Red-breasted Merganser: 1 at Big Johnson Res., El Paso, 11–14 Jun (Dean Shoup, Nena Carmencita Shoup, John Drummond, Greg Miha-lik).

Pacific Loon: 1 at Big Johnson Res., El Paso, 26 May–5 Jul (Mark Peterson, m.ob.).

Common Loon: As many as 3 at Big Johnson Res., El Paso, spring and summer (m.ob.). 3 at Upper Queens Res., Kiowa, 13 Jun (Steven Mlodinow). 1 at Lower Queens Res., Kiowa, 13 Jun (Steven Mlodinow). 1 at Adobe Creek Res., Kiowa, 13 Jun (Steven Mlodinow). As many as 3 at John Martin Res., Bent, 13 Jun–11 Jul (Steven Mlodinow, Tom Behnfield,


Art Hudak). 1 at Oak Ridge SWA, Rio Blanco, 30 Jun–2 Jul (Jan Leonard). 1 at Vega Res., Mesa, 11 Jul (Nic Korte). 1 at Ramah Res. SWA, El Paso, 27–28 Jul (Alan Versaw, Kyle Hawley).

Horned Grebe: 1 at Timnath Res., Larimer, 31 May–2 Jun (David Wade, Steven Mlodinow, Tom Thomson, Nick Komar).

Red-necked Grebe: 1 at Village Lake near Pagosa Springs, Archul-eta, 31 May–7 Jun (Satoko Lincoln, m.ob.). 1 at Big Johnson Res., El Paso, 9–10 Jun (Glenn Walbek, m.ob.).

BROWN BOOBY: 1 at Lefthand Canyon (in the foothills northwest of Boulder) on 22 Jun (Peter Bandurian) and then several days later in Neder-land area, Boulder; first state record.

NEOTROPIC CORMORANT: 1 in Montrose area including Chipe-ta Lake SWA, Montrose, 17–19 Mar and 24 May–20 Aug (Coen Dexter, Brenda Wright, Alan Reed, Jon Horn, m.ob.).

Little Blue Heron: 1 adult at Rog-ers Grove Park in Longmont, Boulder, 15–24 Jul (Mary Brown, m.ob.).

Glossy Ibis: 1 at Neenoshe Res., Kiowa, 4 Jul (Steven Mlodinow).1 near Severance, Weld, 24 Jul (Steven Mlodinow, David Dowell).

RED-SHOULDERED HAWK: 1 at Two Buttes SWA, Baca, 31 Jul (Ty-ler Funk, Travis Mahan, Dan Kasse-baum).

Broad-winged Hawk: 1 in Fort Collins, Larimer, 3 Jun (Nick Komar, Brandon Nooner).1 in Boulder, Boul-der, 8 Jun (Ryan Bushong, Jack Bush-ong).

Black-bellied Plover: 1 at John Martin Res., Bent, 10 Jul (Janeal W.

Thompson). 1 at Ball Res. near Agate, Elbert, 25 Jul (David Suddjian).

Piping Plover: 16 at John Martin Res., Bent, 1 Jul (Ira Sanders).

Upland Sandpiper: 24 near Kio-wa–Prowers border, 19 Jul (Jill White Smith).

Whimbrel: 1 at Beebe Draw, Weld, 9 Jun (Andrew Fontenot). 1 near Lower Latham Res., Weld, 11 Jun (Chris Gilbert). 1 at Blanca Wetlands NWR, Alamosa, 20 Jul (Sam Fason).

Dunlin: 1 at John Martin Res., Bent, 7 Jul (Chris Gilbert).

Red Phalarope: 1 at Timnath Res., Larimer, 30 May–1 Jun (David Wade, Nick Komar, m.ob.).

Bonaparte’s Gull: 1 at Timnath Res., Larimer, 2 Jun (Nick Komar, Tom Thomson).

WESTERN GULL: 1 adult at Smith Res., Costilla, 4 Jun (Ted Floyd) and then Blanca Wetlands NWR, Al-amosa, 22 Jun–23 Aug (Lisa and John Rawinski, m.ob.). 1 second-year bird at Prewitt Res., Washington, 17 Jun–23 Sep (Steven Mlodinow, m.ob.).

Herring Gull: 1 at Upper Queens/Neeskah Res., Kiowa, 4–13 Jun (Da-vid Ely, Steven Mlodinow).

Thayer’s Gull: 1 immature at Pre-witt Res., Washington, 17 Jun–23 Jul (Steven Mlodinow, m.ob.).

Lesser Black-backed Gull: 1 immature at Woods Lake, Weld, 4 Jun–24 Jul (David Dowell, Steven Mlodinow). 2 immature at Prewitt Res., Washington, 17 Jun–23 Jul (Ste-ven Mlodinow, m.ob.). 1 immature at Blanca Wetlands NWR, Alamosa, 16 Jul–23 Aug (David Dowell, m.ob.). 1 immature at Jackson Res., Morgan, 31 Jul–6 Aug (David Dowell).


Caspian Tern: Reports from Ad-ams, Arapahoe, Bent, Larimer, Otero, and Weld, 4 Jun–17 Jul.

Greater Roadrunner: 1 at Beecher Island, Yuma, 10 Jun (Steven Mlodi-now). 1 east of Colorado Springs, El Paso, 10 Jun (Sharon Milito). Other re-ports from Baca, Bent, Huerfano, Las An-imas, Otero, and Prowers, 1 Jun–31 Jul.

Yellow-billed Cuckoo: 1 in Grand Junction, Mesa, 4 Jun (Donna Mc-Fadden). 1 at Carpenter Ranch near Hayden, Routt, 6 Jul (Jason Beason). 1 near Paonia, Delta, 14–17 Jul (Jason Beason).

BLACK-BILLED CUCKOO: 1 at Lake Dorothy, Las Animas, 9 Jul (Ken Blankenship).

Burrowing Owl: 72 near County Road M, Baca, 30 Jul (Travis Mahan, Tyler Funk).

LESSER NIGHTHAWK: 1 at Nucla Sewage Lagoons, Montrose, 7 and 22 Jun (Jeannie Mitchell, Aaron Shipe, Coen Dexter).

White-throated Swift: 4 north-west of Kim, Las Animas, 5 Jun (David Leatherman, David Ely).

RUBY-THROATED HUM-MINGBIRD: 1 adult male in Colora-do City, Pueblo, 19 Jul (David Silver-man). 1 adult male in Lamar, Prowers, 24 Jul (Janeal W. Thompson).

Lewis’s Woodpecker: 2 northwest of Steamboat Springs, Routt, 6 Jul (Tresa Moulton); rare in Yampa val-ley.

Williamson’s Sapsucker: 10 at Staunton SP, Jefferson, 1 Jul (group led by Chris Gilbert).

Red-naped Sapsucker: 12 at As-pen CG near Gould, Jackson, 24 Jul (David Dowell, Steven Mlodinow).

EASTERN WOOD-PEWEE: As many as 2 at Tamarack Ranch SWA, Logan, 3 Jun–12 Jul (Nick Moore, Ste-ven Mlodinow, m.ob.).

Black Phoebe: 1 west of Oak Creek, Routt, 1 Jun (Tresa Moulton). 3 near Carbondale, Garfield, 14 Jul (Mary Harris, m.ob.).

Cassin’s Kingbird: 1 at 10,000 feet elevation near Cottonwood Pass, Gunnison, 5 Jun (group led by Jason Beason). 1 at Bitterbrush SWA near Maybell, Moffat, 13 June (JoAnn & Bob Riggle); very rare in northwestern Colorado.

Scissor-tailed Flycatcher: 1 near Salida, Chaffee, 3 Jun (Jim Wilson, m.ob.). 1 at Battlement Mesa, Gar-field, approx. 9 Jun (Bob Bailey). 1 near Lamar, Prowers, 23 Jun (Jane Stulp). As many as 5 in southwest-ern Lincoln, 3–26 Jul (Larry Modes-itt, m.ob.). 1 northeast of Briggsdale, Weld, 10 Jul (Jeff Maw, Earl Johnson).

White-eyed Vireo: 1 near Blanca, Costilla, 5 Jun (Mark Peterson).

Bell’s Vireo: 1 at Valco Ponds SWA, Pueblo, 19 Jun (Robb Hinds). Other reports from Logan, Sedgwick, and Yuma, 3 Jun–23 Jul.

Yellow-throated Vireo: 1 at Crow Valley CG, Weld, 29 May–2 June (Glenn Walbek, Steve Larson, m.ob.).

PACIFIC WREN: As many as 4 at Calypso Cascades in Wild Basin area of Rocky Mountain NP, Boulder, 24 Jun–24 Jul (Steven Mlodinow, Kathy Mihm Dunning, Christian Nunes, m.ob.)

Carolina Wren: 1 at Prewitt Res., Washington, 23 Jul (William Kaemp-fer). 1 in Pueblo, Pueblo, 24 Jul (Rick Clawges).


Wood Thrush: 1 at Corwina Park northeast of Evergreen, Jefferson, 6 Jun (Frank Farrell).

Black-and-white Warbler: 2 at Castlewood Canyon SP, Douglas, 30 May–14 Jul (Hugh Kingery, Glenn Walbek, m.ob.). 1 at Black Canyon of the Gunnison NP, Montrose, 22 Jun (Bob Andrews).

Northern Parula: 1 at Castlewood Canyon SP, Douglas, 4–6 Jun (Glenn Walbek, Tim Ryan). 1 at Gateway NA in Poudre Canyon, Larimer, 21 Jun (David Wade). 1 in Gunnison, Gun-nison, 27 Jun (Steve Larson, Glenn Walbek).

Magnolia Warbler: 1 at Prewitt Res., Washington, 18 Jul (Steven Mlodinow).

Chestnut-sided Warbler: 1 in Fort Collins, Larimer, 2 Jun (Nick Komar, Brandon Nooner).

Yellow-throated Warbler: 1 in Pueblo, Pueblo, 3 Jul (Van Truan).

Grasshopper Sparrow: 3 in Nucla, Montrose, 10 Jul (Brenda Wright & Coen Dexter).

BAIRD’S SPARROW: 1 at County Road 5, Larimer, 3 Jun (Mark Peterson, Glenn Walbek). 2 at Mead-ow Springs Ranch near Carr, Weld, 10 Jun (Walter Wehtje). As many as 20 at Soapstone Prairie NA, Larimer, 15 Jun–6 Aug (Norm Lewis, Megan Miller, Randall Siebert, m.ob.).

Clay-colored Sparrow: 1 at Lake Dorothy, Las Animas, 9 Jul (Ken Blan-kenship). 1 at Ken Caryl, Jefferson, 16 Jul (David Suddjian).

White-throated Sparrow: 1 at Cu-recanti NRA, Gunnison, 5 Jun (group led by Jason Beason).

Grasshopper Sparrow: 6 near

Craig, Moffat, 30 Jun (Forrest Luke).EASTERN TOWHEE: 1 at

Tamarack Ranch SWA, Logan, 5 Jun (Mark Chavez, Tom Behnfield, Art Hudak). 1 at Dinosaur NM, Moffat, 14–15 Jun (Peter Colasanti); pending review by CBRC, would be first west-ern Colorado record.

Summer Tanager: 1 at Pueblo Res., Pueblo, 2 Jun (Robert Priddy). 1 at Fox Ranch, Yuma, 20 Jun (Ste-ven Mlodinow). 1 at Yellowjacket Canyon, Montezuma, 26 Jun (Glenn Walbek, Steve Larson). As many as 2 at Cottonwood Canyon, Las Animas/Baca, 9–30 Jul (Norman Erthal, Kathy Mihm Dunning, Joey Kellner, Darth Aves, Tyler Funk, Travis Mahan, Dan Kassebaum).

Scarlet Tanager: 1 male at Monte Vista NWR, Rio Grande, 5 Jun (Casey Setash, Katherine Scott). 1 female south of Saguache, Saguache, 5 Jun (Daniel Flemming). 1 male at Boul-der Valley Ranch, Boulder, 6 Jun (Lark Latch).

Painted Bunting: As many as 3 in Picture Canyon, Baca, 5 May–24 Jul (m.ob.).

Dickcissel: As many as 12 in Wet-more area, Custer, 3–15 Jun (Rich Miller, Brandon K. Percival, Van Truan). 1 near Aguilar, Las Animas, 18 Jun (Joey Kellner, Kathy Mihm Dunning). 2 near Walsenburg, Huer-fano, 18 Jun (Kathy Mihm Dunning, Joey Kellner). 1 along Road CC, Conejos, 26 Jun (John Stump). 39 at Tamarack Ranch SWA, Logan, 2 Jul (Kathy Mihm Dunning, Joey Kellner, David Dowell). 1 at Beulah, Pueblo, 7 Jul (Van Truan). 1 at Monte Vista NWR, Rio Grande, 8 Jul (Stu Wilson).


Wood Duck, Lamar Community Col-lege, Prowers County, 2 June 2016. Photo by Janeal Thompson

Dusky Grouse, Uncompahgre Plateau, Montrose County, 6 June 2016. Photo by Brenda Wright

Turkey Vulture, Lamar Community College, Prowers County, 2 June 2016. Photo by Janeal Thompson

Piping Plover, Jumbo Reservoir, Sedg-wick County, 27 May 2016. Photo by Kathy Mihm Dunning

Pomarine Jaeger, Chatfield State Park, Jefferson/Douglas Counties, 16 October 2016. Photo by Peter Burke

Burrowing Owl juvenile, Squirrel Creek Road, El Paso County, 25 June 2016. Photo by Bill Maynard


Broad-tailed Hummingbird, Sentinel Moun-tain, South Fork, Rio Grande County, 17 July 2016. Photo by Janeal Thompson

Rufous Hummingbird, Sentinel Moun-tain, South Fork, Rio Grande County, 17 July 2016. Photo by Janeal Thompson

Woodhouse’s Scrub-Jay, Heil Valley Ranch, Boulder County, 6 July 2016. Photo by Todd Deininger

Baird’s Sparrow, Soapstone Prairie Natural Area, Larimer County, 20 July 2016. Photo by David Leatherman

Baird’s Sparrow close-up, Soapstone Prai-rie Natural Area, Larimer County, 20 July 2016. Photo by David Leatherman


As many as 8 at Lake Dorothy, Las Animas, 9–17 Jul (Ken Blankenship, m.ob.). Several along CR 21.6 and State Hwy 12 near Vigil and Bosque del Oso SWA in southwestern Las Animas, 9 Jul (David Leatherman). 35 near Prewitt Res., Washington, 18 Jul (Steven Mlodinow). 1 at Home Lake SWA near Monte Vista, Rio Grande, 27 Jul (Kathy Mihm Dunning). Other reports from Adams, Arapahoe, Baca, Bent, Boulder, Douglas, El Paso, Elbert, Fremont, Kiowa, Kit Carson, Jefferson, Larimer, Las Animas, Lincoln, Logan, Morgan, Otero, Phillips, Prowers, Pueb-lo, Sedgwick, Washington, Weld, and Yuma, 1 Jun–31 Jul.

EASTERN MEADOWLARK: 1 at Rocky Mountain Arsenal NWR, Adams, 8–17 Jun (Steve Rash, m.ob.). 1 at La Garita, Saguache, 16 Jun (Lori Harvey). 1 at John Martin Res., Bent, 27 Jun (Steven Mlodinow).

Scott’s Oriole: 2 northwest of Kim, Las Animas, 5–18 Jun (David Leather-man, David Ely, Glenn Walbek, Mark Peterson). Other reports from Mesa, 9 May–9 Jul.

Addendum to Spring 2016 “News from the Field”

COUCH’S KINGBIRD: 1 in north Lamar, Prowers, 19 Apr (David Leatherman); first state record.

Rose-breasted Grosbeak, Skunk Canyon Trail, Boulder County, 18 May 2016. Photo by Jane Baryames

Dickcissel, Chico Basin Ranch, Pueblo County, 9 June 2016. Photo by Bill Maynard

ACkNOWLEDgmENTsThe sightings reported by contributing observers to eBird, COBirds, and the West Slope Birding Network are greatly appreciated. Volunteer compilers contributed significantly to this report: Jim Beatty (southwest), Coen Dexter (west), John Drummond (south-east), Dave Leatherman, Forrest Luke (northwest), Rich Miller, Brandon Percival, John Rawinski (San Luis Valley), and David Silverman. Much of the information in this re-port was obtained from the eBird Basic Dataset from the Cornell Lab of Ornithology, Ithaca, New York.

David Dowell, [email protected]


THE HUNGRY BIRD

Green Ash SeedsDave Leatherman

It’s a “samara.” That is, a “dry, indehiscent winged fruit.” So it says in the key to the Oleaceae (a.k.a. “the olive family”) in the wonderful new botany book, Flora of Colorado (Ackerfield 2015). But what does it all mean? “Dry” is understandable enough. “Indehiscent” describes a ripened ovary with enclosed seeds that does not open when mature. “Winged” means the seed or kernel is attached to a blade that aids in its dispersal, if and when it falls from the branch tip where it devel-oped (Figs. 1 and 2).

Samaras are the norm in many of our familiar deciduous trees, including maples and elms. Those maple “helicopter seeds” are sama-ras. The particular samara featured here is that of green ash (Fraxinus pennsylvanica), a nonnative tree in Colorado that is widely planted and also has naturalized in several riparian corridors. This tree’s seeds are eaten by many bird species and could be called favorites, indeed staples, of a few in winter. Green ash is quite prominent in most Colorado low-elevation urban landscapes but would appear to have a rocky future in light of the emerald ash borer’s recent arrival and inevitable spread. For these reasons it seems worthy of discussion.

In the woody world of trees, sexual segregation is rare. The stan-dard arrangement is for female flowers and male flowers to coexist on the same plant, often mere centimeters apart. Apparently enough male pollen from trees of the same kind next door or even quite a distance away finds the female flowers that the inbreeding which oc-curs due to brother–sister shenanigans is not a serious issue. This con-dition of an organism harboring both sexes of reproductive parts is termed “monoecious” (“one house”). Organisms with only one type of sex organ are “dioecious.” Girls over here. Boys over there. Hu-mans are dioecious and so are members of the ash tree genus Fraxinus. Other well-known dioecious tree types are poplars including aspen, maple, honeylocust, and many others. Nursery offerings of dioecious species described as “seedless,” “cottonless,” or “podless” are just an-other way of saying they are male plants.

So, not all ash trees are super attractive to birds. Unless male trees are stressed and have issues with or harbor insects like oystershell scale, leafcurl aphids, lace bugs, plant bugs, ash bark beetle, borers, certain caterpillars, and a few others, they can be rather birdless. An exception to this would be as a nesting site for robins and goldfinches.

Female trees with seeds are another story. A samara-laden ash can be alive with birds September through April. Most birds I have seen


Fig. 1. Female green ash showing heavy seed crop. 28 September 2010, Grand-view Cemetery, Fort Collins (Lar-imer County), CO. Photo by David Leatherman

Fig. 2. Dry samara as they appear October through spring (top) and seed (bottom) as it would appear after extraction from the left end of the samara. Photo by David Leatherman

eating them are finches and woodpeckers. The dehiscent quality of ash fruits means active extraction of the seed or kernel is required. Because the oarlike seeds hang in clusters from old flower stalks at the ends of very small–diameter branches, getting the seed out is not something easily accomplished on the fly. The seed usually has to be detached, braced somehow, and drilled. I have seen bracing accom-plished in a couple of ways. Either the individual samara is pulled from the tree and wedged into bark or some-thing else where pecking and picking is possible, or it is pulled and stood upon.

On 1 November 2016 at Grand-view Cemetery in Fort Collins, I watched a Black-capped Chickadee making a meal out of ash seeds in skill-ful, methodical fashion. It landed near the seeds, flitted over, plucked one with its beak, laid it on a twig under its lower belly, placed one foot at each end of the oar, and then wailed at the seed end (Figs. 3 and 4). By chipping open a slit atop the seed (which occu-pies roughly one-third of the samara’s length) it was removed in about 5 seconds. Repeat, repeat, repeat, until full, the attention span is reached, an accipiter is sensed 500 yards distant, a buddy chickadee describes a better adventure, who knows? Chickadees


seem the epitome of rabbit trailing, but I am probably selling short their hyper mastery of the myriad options.

Other birds exploiting ash seeds during the cool months of au-tumn, winter, and early spring are predictable, seed-loving types like House Finch, American Goldfinch, Pine Siskin, and Dark-eyed Jun-co (Figs. 5 and 6). Many other granivores must share this habit. What have you seen? It is hard to imagine what House Finches would do without the availability of green ash seeds.

Downy Woodpeckers occasionally eat ash seeds but more often than not are in ash to exploit bark beetles and scale insects inhabit-ing the same branches hanging with seeds. Indeed, stress in plants often triggers heavy seed production coincident with predisposition to insect attack.

During the winter of 1984–1985 several Pine Grosbeaks took the altitudinal elevator down several floors from Cameron Pass and other high sites to Fort Collins. While in town they mostly utilized juniper berries, crabapples varieties with small fruits, and, yes, female green ash trees loaded with seeds.

As is the case with honeylocust seed weevils in honeylocust beans (see “The Hungry Bird” in the Winter 2016 issue, Vol.50(1), of Colo-rado Birds), it is possible a small part of the attraction birds have for ash seeds is their being fortified with weevils. Three members of the genus Lygnyodes feed on ash seeds, with L. helvolus occurring in Colo-rado. However the life cycle of this weevil is such that late spring thru late summer is the only period when larvae occur within the seeds. This does not match when most bird feeding on ash seeds is observed in my experience (Cranshaw 2014).

The Issue of Emerald Ash BorerArborists and players of the stock market have long known, or

at least should know, there is risk in putting too much investment in any one commodity. “Diversity” is an overused but nevertheless beautiful word, especially when it pertains to things like people, portfolios, and biodiversity, including our collections of ornamental trees. It could be argued in the case of green ash that many cities and towns overdid it. Just like many cities in the East and Midwest did with monocultured neighborhoods of American elm, we have set ourselves up for epidemic ash losses. With elms, the grim reaper was an exotic fungus and its exotic bark beetle vector leading to massive mortality from Dutch elm disease. Inventories of trees on the com-puters of Colorado’s modern urban foresters often show percentages of ash in the 10–20% range. For a municipality boasting tens of thou-sands of trees, such proportions compute to a lot of ash trees. Boulder,


where the dreaded emerald ash borer (Agrilus fumipennis) first showed up in Colorado in 2013, is estimated to have 98,000 ash trees. The Denver Metro area has an estimated 1.45 million ash.

Emerald ash borer (EAB) was first detected on United States soil in Detroit, Michigan, in 1990. It probably actually got there via wooden dunnage used in ships to stabilize loads up to ten years ear-lier. But difficulties in its detection allowed its escape from the U.S. Department of Agriculture’s radar. In an oft-repeated scenario with introduced organisms, in the absence of evolved checks and balances from where native (in this case, Asia), it has marched steadily across our country and now has been found in 27 states and 2 Canadian provinces. In the process it has killed untold millions of planted and forest ash trees. In the way of hope, progress has been made in pre-ventive and curative treatments over the last 26 years but it still re-mains a serious threat to our ash resource.

This member of the flatheaded wood borer family Buprestidae is a narrow, green beetle about 1.5 centimeters long that develops un-der the bark in the cambium/phloem region and in the outer layers of xylem wood, thus girdling and often killing the host tree. After emergence as an adult, it feeds for a time on tender shoots and leaves. It spreads somewhat by flying, but its long-distance travel is mostly attributable to the ill-advised actions of humans moving infested fire-wood, nursery stock, and other wood products from one location to another.

Colorado has access to the best information available and read-ers are directed to the Colorado Department of Agriculture website (http//www.colorado.gov/pacific/agplants/emerald-ash-borer). It contains excellent information on recognition of EAB, management options, a guide to recommended trees to replace ash lost to EAB, and much more. On this website, the “Front Range Tree Recom-mendation List” lists 100s of tree varieties according to one of four categories: generally recommended, conditionally recommended, po-tential/unproven, and not recommended. These categories were con-structed by local experts primarily in regard to replacing casualties to EAB, but the list has great general utility for anyone wondering, “What’s a good tree to plant around here?”

Spraying strategies designed to prevent and suppress EAB are (Herms 2014):

• soilappliedsystemics• trunk-injectedsystemics• noninvasivesystemicbasaltrunksprays• protectivecoversprays


Fig. 3. Black-capped Chickadee imme-diately after pulling individual samara from a cluster. Grandview Cemetery, Fort Collins, 1 November 2016. Photo by David Leatherman

Fig. 4. Black-capped Chickadee extracting seed from green ash samara by standing on it and chipping slit over the seed. Grand-view Cemetery, Fort Collins. 1 Novem-ber 2016. Photo by David Leatherman

Fig. 5. Female House Finch eating green ash seed. Extraction of the seed is usually executed by deft manipulation of the samara while in the bill. Grandview Cemetery, Fort Collins, 3 November 2016. Photo by David Leatherman

Fig. 6. Several ash samaras found under a tree in which House Finches fed, showing slits cut during removal of seeds. Grandview Cemetery, Fort Collins, 25 September 2010. Photo by David Leatherman


Of interest to birders, most of these techniques and the materials currently registered for use have been evaluated as being of zero to low risk to water quality, nontarget organisms (including woodpeck-ers that might prey on larvae within infested trees), and unexpected consequences to the trees themselves (Hahn 2011). To my knowl-edge, there has not been a study that looks at these treatments and their potential impact on pesticide levels in seeds. My guess would be this also would be negligible. Of course, any application of pesticides should be done with extreme care, particularly near bodies of water.

For the sake of birds that utilize ash as one of their favorite eat-ing places, it behooves all owners of ash trees to get up to speed on emerald ash borer.

LITERATURE CITEDAckerfield, J. 2015. Flora of Colorado. Botanical Miscellany No.41, BRIT Press, Ft.

Worth, TX.Cranshaw, W. 2014. Insects and diseases of woody plants in Colorado. Colorado State

University Cooperative Extension Bulletin 506A. Ft. Collins, CO.Hahn, J., D. A. Herms, and D. G. McCullough. 2011. Frequently asked questions regard-

ing potential side effects of systemic insecticides used to control emerald ash borer. USDA Forest Service and Michigan State University. http://www.emeraldashborer.info

Herms, D. A., D. G. McCullough, D. R. Smitley, C. S. Clifford, and W. Cranshaw. 2014. Insecticide Options for Protecting Ash Trees from Emerald Ash Borer, 2nd Ed. North Central IPM Center Bulletin, University of Illinois, Urbana-Champaign.

Dave Leatherman, [email protected]


An Observation of Common Poorwill Foraging in Vehicle Headlights Jonathan Gendzier and Jonathon Poe

At dusk on the evening of 2 September 2016, two observers, one birder and one non-birder, traveled by car on a section of Black Canyon Road in Montrose County, Colorado, extending from the North Rim Ranger Station of Black Canyon of the Gunnison National Park to Road C77, with access to the Gun-nison Gorge National Conservation Area. Some light was still visible in the sky, but at ground level the headlights were necessary to illuminate the road, and visibility was low outside this zone of illumination.

The driving non-birder suddenly stopped the car and exclaimed that he had “just hit an owl!” The birder urged that he back up the vehicle, suspecting that the casualty might have been Western Burrowing Owl (Athene cunicularia hy-pugaea). However, a cursory inspection of the illuminated dirt road showed no signs of any roadkilled bird. Instead, on the ground, at the edge of the road, was a live nightjar, eyes shining. Calls of poor-will emanating from the surrounding sagebrush assisted the birder, a Southerner visiting Colorado, in identifying the species as Common Poorwill (Phalaenoptilus nuttallii). Attempts at obtaining photographs with an iPhone were unsuccessful.

As we proceeded, slowly, down Black Canyon Road, numerous Common Poorwill could be seen, both on the ground and in low flight, hunting insects along the road. Some were frozen like jacklighted deer in the beam of the head-lights. Interestingly, others soon began to use the light to assist their foraging: several individuals dashed from one side of the road to the other in front of the car, and could be seen swerving in the headlights to catch insects. This was repeated every several yards as we continued.

Most strikingly, one individual, flushed from the road at our approach, flew in our direction of travel, fluttering directly in the beam of the headlights, about even with the height of the bumper, a few feet in front of the vehicle. At first we thought that this bird did not have the good sense to veer left or right, but then we clearly saw it catch an insect. The poorwill led us down the road on its foraging flight for a good 10 to 15 seconds.

A search of the SORA database and the broader internet revealed common references to spotting nightjars in vehicle headlights, especially via eyeshine, but the authors did not locate accounts of similar hunting behavior.

Altogether we saw an estimated 15 to 20 or more Common Poorwill in just a few minutes of travel on Black Canyon Road. Activity seemed to taper off soon after dusk, although Common Poorwill could be heard calling on occasion at points through the night and into the dawn.


Barn Owls Nesting in Nest Boxes in Boulder CountyScott Rashid

AbstractOver the past 25 years it has become harder and harder for me to

find nesting Barn Owls (Tyto alba) in Boulder County. This raised a couple of questions. Is the lack of Barn Owls due to a shortage of nest-ing sites? Or a lack of prey? With the assistance of several volunteers, ten Barn Owl nest boxes were constructed and placed on buildings in Boulder County. Soon after placement of the boxes, Barn Owls were found nesting in two of the boxes. One pair’s nesting season was shown live on the internet using two Drop Cam cameras and is detailed below.

Barn Owls (Tyto alba) have long been a nesting species in Boul-der County (Jones 2010). However, over the past several years, ac-tive nests were becoming harder to find. Therefore, in February of

Barn Owl nest box with cameras. Note the camera on the side of the nest box; placed there, so we can watch the nesting activities in real time.


2015, members of the Colorado Avian Research and Rehabilitation Institute (CARRI) in Estes Park decided to build and place nest-ing boxes for Barn Owls in Boulder County. With a generous donation from the Boulder Audubon Society, wood was purchased and nest boxes were built.

The horizontal boxes were built using ½-inch plywood and were 15 inches high (38 cm) by 15 inches deep and 30 inches (76 cm) long, with a 5-inch (12.7-cm) entrance hole on the front left side of the box. The right half of the nest box opens, enabling us to extract any owls to band and/or to clean out the

nest box after the nesting season.On 18 January 2014, one of the ten Barn Owl nest boxes was

placed on the garage of a private residence just outside of Lafayette, Colorado. Several days later a 3-inch (7.6-cm) hole was drilled on the left side of the box and a camera was attached to the outside, enabling us to watch what was happening in the box.

On the evening of 6 May 2014, a male Barn Owl was seen inside the nest box vocalizing, presumably to entice his mate to enter the nest box. He would enter the nest box with deer mice (Peromyscus maniculatus) and voles (Microtus spp.), place them on the bottom of the nest box, then exit.

The first evening that the female entered the box was 8 May. She seemed reluctant at first, and only remained in the box for a few min-utes before exiting. It was not until 10 May that she remained in the box for the entire day and night, only exiting at night for a few min-utes at a time. From that day until the first egg was laid, the female was not seen hunting for herself. Presumably, the male did all of the hunting for himself and his mate.

Presumably, the female was reluctant to exert much energy as she was conserving it to enable her to create the eggs that she would soon begin laying. From the time the female accepted the nest the male and female copulated an average of ten times per evening. This continued until the last egg had hatched.

On 18 May, at 9:24 a.m., the first egg appeared. There were sev-eral voles in the nest box, some partially eaten and some still whole.

Roosting adult female Barn Owl.


Two days later the second egg was laid. The third egg appeared the evening of the 22nd. The fourth egg was laid about 11:00 a.m. on the 25th. The fifth egg appeared on the 27th, the sixth was laid on the 29th. On 1 June, about 5:00 a.m., egg number 7 was laid; on the 3rd, egg number 8, on the 5th, egg number 9, and the last egg was laid on Saturday, 7 June.

The first egg hatched at about 6:45 a.m. on 19 June; the second hatched at 1:04 a.m. on 21 June; two evenings later at 9:36 p.m. the third egg hatched. The fourth hatched at 8:24 a.m. on 25 June. The remaining eggs hatched in two-day intervals until the last egg hatched on 4 July.

At hatching, the owlets are primarily pink, with a few white down feathers on their heads, wings, and backs. Their eyes are closed yet the young birds can move short distances to be fed. Their food beg-ging calls are a kind of harsh shhhhh.

By 28 June the first and second owlets’ eyes had opened. Barn Owls’ eyes open at about nine days of age. Also at this age, the old-est owlets can regulate their own body temperature as they are often

Typical Barn Owl habitat in Boulder County. Note the unfurrowed ground and the tree line. The unplowed field enables voles to live year round and the trees enable the adult birds to roost away from the nest during the day.


away from their mother. The owlets spend a great deal of their day sleeping, while the adult female appears to never sleep. She is con-stantly tending to the owlets and incubating the unhatched eggs.

I have often won-dered why Barn Owls have such long legs. It became apparent while watching the adult fe-male. The reason for long legs may be due, in

part, to the female’s need to incubate unhatched eggs and feed young owlets at the same time. Long legs also allow the adult male to catch mice and voles in tall grass—their long legs enable the adult birds to dive feet first into tall grass, catch a small animal, then take off flying out of the grass with ease.

The last owlet hatched early on the morning of the 11 July. Unfor-tunately, the three youngest owlets did not survive. The land owner found one of the owlets on the ground under the nest box. My guess is that the nest box was simply too small for such a large family.

By this time, the female spent several minutes every day or two scratching at the bottom of the box. This is a bit puzzling to me. Was it simply to break up the pellets, making the bottom of the box softer and easier for her owlets to stand on? Was she just making the floor of the box flat? Or maybe she was just trying to tidy up her home; I really do not know. However, there were pellets and debris on the ground under several of the nest boxes in 2015, so house-cleaning would seem to be a common practice of Barn Owls.

For the first several weeks after the young hatch, the male is the sole provider for himself, his mate, and the owlets. The female was first seen bringing a vole to her nestlings on 21 July. There is no way to know if she caught it herself, or if the male delivered it to her out-side of the nest and she then brought it to the owlets.

The evening of 22–23 July was the first occasion when both adults were noted hunting for the family. Until this evening, the female only remained out of the nest box for a few minutes at a time. On this particular evening, she was out of the nest for over two hours.

1 August was the first day that the female remained out of the nest

Clutch of Barn Owl eggs.


box during daylight hours. This was a bit troubling because one of our goals was to capture and band her with the intent of determining if the female returns to the same nest site in subsequent years. If we could capture and band her in 2014, and she returned to the nest in consecutive years, we would be able to determine that.

It was decided to band the owlets on 2 August. That morning, much to my surprise, the female was in the nest box with her owlets. Several volunteers of CARRI arrived at the nest site early that morn-ing. David Neils, one of the CARRI volunteers, placed a net over the entrance of the nest box so that, if the adult female exited the box, she would be captured in the net. I climbed a ladder and opened the door. The adult female was standing right next to the door; I slowly reached into the box and gently placed my hands around her, removed her from the box, and closed the door so none of the owlets would fall out. I climbed down the ladder and placed the female Barn Owl in a plastic pet carrier and covered the carrier with a towel. I returned to the nest box and one by one took the owlets from the box and placed them in pet carriers to be banded.

Each owlet was banded with a U.S. Fish and Wildlife Service alu-minum leg band. As I was banding the owlets, the CARRI volunteers

Barn Owl nestlings just a few days before fledging.


took turns removing all of the prey remains and pellets from the nest box. This filled two five-gallon buckets! The volunteers then placed about 2 inches (5 cm) of wood shavings on the bottom of the box so the owlets would have a soft floor to perch on and lay on.

The owlets were all banded and placed back in the nest box as the hole remained covered. This way none of them would be able to jump out. The adult female was banded and measured, then she was also placed back into the nest box. She was a second-year owl, mean-ing she had hatched in 2013.

Barn Owlets fledge over several evenings. The oldest owlets fledge first. They often fly out of the nest and remain out of the box for sev-eral minutes and even a couple of hours, but return to the nest box before sunrise and remain inside during the day. When inside and outside the nest box the owlets seem to constantly food-beg.

About the time the first owlet fledges, the female appears to fly away and the male is left to finish raising the owlets that are still inside the nest box as well as tend to the fledglings. This may be why the female allows the male to mate with her so many times during incubation and after the first few owlets hatch; maybe it is some kind of a trade-off.

When the owlets do leave the nest box for good, they are fully feathered and look just like adult owls. The evening of 17 October was the last time any of the owlets were seen on or in the nest box; 17 November was the last time any Barn Owls were seen in or on the nest box in 2014.

ACkNOWLEDgmENTsI would like to thank, David Neils, Naseem Munchi, Mike Tupper, Beth Sherman, Sarah Kormos, Steve Jones, Pam Piombino, and the board members of the Boulder County Audubon Society.

LITERATURE CITED Jones, S. 2010. Owls of Boulder County. Boulder County Nature Association, Boulder,

CO.

Scott Rashid, [email protected]


‘Green-winged’ TealTony Leukering

Quick! What is the color of the inner part of the speculum on a Green-winged Teal?

“What is a ‘speculum,’” you might ask. To paraphrase a couple of online definitions, it is a patch of colorful secondaries that contrast with the color of much of the rest of the wing and, in the ABA area, used primarily with ducks. I am something of a purist in preferring to use the term only for patches of iridescent color, rather than those created by pigment. Thus, I do not consider White-winged Scoter to have a speculum, but I am almost certainly in the minority with that belief. Of course, even those that do believe that White-winged Scoter has a speculum are in the minority, as most people who know the term—and that is certainly a minority in itself—think of the medical tool used by gynecologists.

So, what is the color of the inner part of the speculum on a Green-winged Teal? Now, if you paid attention to the last paragraph, you might be able to waffle on the response, with something like, “Well, it depends on the angle of light.” That is true, because iridescence in “animals such as on the feathers of birds and the scales of butterflies, interference is cre-ated by a range of photonic mechanisms, including diffraction gratings, selective mirrors, photonic crystals, crystal fibres, matrices of nanochan-nels and proteins that can vary their configuration” (Wikipedia 2016).

Whew! Did you get that? I think I need to get me some of them there photonic crystals. Perhaps this one will work (CLO 2016): “The irides-cent colors… are the result of the refraction of incident light caused by the microscopic structure of the feather barbules. The refraction works like a prism, splitting the light into rich, component colors. As the viewing angle changes, the refracted light becomes visible in a glowing, shimmering iridescent display.”

That’s better. Even simpler, however, iridescence in feathers is cre-ated by the structure of those feathers and their ability to affect the wavelength of light that enters the feather in such a way as to emit only certain parts of the color spectrum. Additionally, which part of the spec-trum that an observer sees is dependent upon the angle created by the light source, the bird, and the viewer. This last is the reason that male Mallards sometimes look like they have blue or purple heads rather than green heads. Why head color in scaup is a very poor ID character. Why male Broad-tailed Hummingbirds can suddenly become Black-chinned Hummingbirds when they turn their heads slightly. Typically, the “true” color—or what we birders often think is the true color (such as Mallard’s

IN THE SCOPE


green head)—of any iridescent feather requires the observer to have the light source (usually, the sun) nearly behind her/him and the feather in question facing the sun. In actuality, the feather does have a “true” color, but it is usually not the color that we perceive. As example, those iridescent feathers that make up the train of uppertail coverts of Indian Peafowl males—the feathers that are usually called the “tail,” but which aren’t tail feathers at all—are actually pigmented brown.

Now that I am five paragraphs along in this essay, I will get back to the subject. What is the color of the inner part of the speculum on a Green-winged Teal? If you answered, “green,” good on ya. That green speculum is the reason that we call Anas crecca carolina Green-winged Teal.

Now that we’ve got the easy question out of the way, what is the color of the inner part of the speculum on a Blue-winged Teal? Did you answer, “green?” We-elllllll…

Very good.For those that stumbled, this is one of the problems of naming bird

species based on a field character that is not unique to the species. I mean, if Green-winged Teal has a green speculum, certainly Blue-winged Teal would have a blue speculum. Right? As those that responded “green” to the second question know, Blue-winged Teal got its name, not from the speculum, but from the lesser and median coverts – the front part of the topside of the wing, rather than the back part of the topside of the wing. Blue-winged Teal has a green speculum. In fact, all duck species that oc-cur in the ABA area that have “teal” in their name (as well as the teal that does not have “teal” in its name, Northern Shoveler) have green specula. In fact, of the nine duck species in the genus Anas (most of the so-called “dabbling ducks”) that occur regularly in Colorado (“regular” being defined as not on the state’s review list), seven of them sport green specula; Gadwall and Mallard are the odd ducks out.

On the back cover of this issue are photographs of the speculum of each of five ducks, all having green specula. Can you find the Green-winged Teal? What other species are represented?

LITERATURE CITED[CLO] Cornell Laboratory of Ornithology. 2016. How birds make colorful feathers. Cor-

nell Lab of Ornithology, Ithaca, NY. Accessed October 2016 from https://academy.allaboutbirds.org/how-birds-make-colorful-feathers/.

Wikipedia. 2016. Structural coloration. Wikipedia, the Free Encyclopedia. Accessed October 2016 from https://en.wikipedia.org/wiki/Structural_coloration.

Tony Leukering, 1 Pindo Palm St. W, Largo, FL 33770 ([email protected])




The Colorado Field Ornithologists’ Quarterly

Instructions for contributors to Colorado Birds

Colorado Birds is devoted to the field study of birds in Colorado. We invite you to submit articles of general or scientific interest for publication. Authors are encouraged to submit materials that contribute to the enjoyment and understanding of birds in Colo-rado. The preferred submission method is via email attachment to the Colorado Birds editor, [email protected].

Photos or other art may be submitted in black and white or color. Files should be saved as high-resolution jpeg or similar format and must be a minimum of 900 x 750 pixels. Please DO NOT save photos in MS Word or otherwise embed within a document. Include photo captions along with the photographer’s name, where and when taken and other relevant information. All photos should be sent to the Colorado Birds editor, [email protected].

Submissions of photographs of birds observed in Colorado are welcome. Please in-clude all relevant details including where and when the photo was taken and send to the Colorado Birds editor, [email protected].

Contributors who are not members of CFO will, upon request, receive a complimen-tary copy of the issue of Colorado Birds in which their articles appear.

In the Scope: 'Green-winged' Teal ..................... 51

Note: Complete captions will be provided for the pictures when the solution is presented in a subsequent installment of “In The Scope.”

Fig. 1. Fish Springs N.W.R., Juab County, UT, 24 June 2009. Photo by Ken Behrens

Fig. 2. Hay Lake, Glacier County, MT, 19 August 2015. Photo by Tony Leu-kering

Fig. 3. Cape May, Cape May Coun-ty, NJ, 13 December 2015. Photo by George Armistead

Fig. 4. Antelope Island Causeway, Davis Co., UT, 14 January 2008. Photo by Ken Behrens

Fig. 5. Hudson Beach, Pasco County, FL, 17 January 2016. Photo by Tony Leukering

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