Slide 1Biology and Conservation of American Oystercatchers on the Outer Banks of North Carolina - 20 years of collaborative
focal species research and management Ted Simons
USGS Cooperative Fish and Wildlife Research Unit Department of Applied Ecology, NC State University
Outline • Overview of American Oystercatcher Biology • AMOY Research on the Outer Banks
– Changes in Distribution and Abundance – Factors affecting reproductive success
• History of American Oystercatcher Working Group
Oystercatchers of the Americas
Haematopus palliatus Taxonomic Status
• Five subspecies are currently recognized
• The subspecies galapagensis, endemic to the Galapagos islands, may be a separate species
• Regularly hybridizes with H. bachmani, and hybrids with H. ater are known
H. palliatus subspecies • palliatus - Atlantic and
Caribbean coasts North America, Central America, South America to southern Brazil, West Indies, and Pacific Central America
• durnfordi - Argentina (and Uruguay?)
palliatus subspecies
Feeding • Food: almost exclusively
shellfish and other marine invertebrates that inhabit intertidal areas.
• Foraging microhabitat: restricted to intertidal sand or mud flats, oyster or mussel reefs or shoals; less commonly, rocky shorelines
Breeding Biology • Strong mate and nest site
fidelity • In North America, the nesting
season begins in late March- early May
• Oystercatchers lay 2-4 eggs in a shallow scrape
• Incubation takes 27 days, during which time the eggs are vulnerable to nest predators, flooding, and exposure
• Precocial chicks, 35-45 days to develop flight capability
• Unlike most other shorebirds young fed by adults up to 6 weeks after fledging
Conservation Status
• US and Canada: Species of Greatest Concern
• El Salvador and Mexico: Endangered
• Guatemala: Near Threatened
Population estimates: palliatus Distribution Season Individuals
Coasts E & S USA
Non-breeding 550 550
Brazil Breeding 6500
palliatus total - 21,326
Clay et al. in Ens, B.J. and L.G. Underhill. 2014. Conservation Status of Oystercatchers around the World. International Wader Studies Number 20.
US SHOREBIRD CONSERVATION PLAN SHOREBIRDS OF CONSERVATION CONCERN – 2016 LIST
ESA-listed
• Black-necked Stilt (knudseni) • Snowy Plover (nivosus [Pacific Coast]) • Piping Plover • Eskimo Curlew • Red Knot (rufa)
Greatest Concern
• American Oystercatcher (North America breeding palliatus) • Snowy Plover (nivosus [Interior/Gulf Coast] and tenuirostris) • Wilson’s Plover (North America breeding wilsonia) • Mountain Plover • Bristle-thighed Curlew • Bar-tailed Godwit (baueri) • Red Knot (roselaari)
Oystercatcher Research in North Carolina • Research began on the
Outer Banks in 1997 • Collaborative effort with
the NC Wildlife Resources Commission, NPS, USFWS, NC Audubon
• Studies of breeding biology now include data from over ~3,000 nesting attempts (~325 breeding pairs)
Focal Species Conservation • Widespread along Atlantic and
Gulf Coasts • Sensitive to a variety of factors
affecting coastal resources – Habitat loss, coastal
development – Pressure from human recreation – Pollution – Non-native predators
• Large, charismatic, easily identified
• Demographic Studies – Oystercatchers are easily
marked, allowing us to identify individuals from year to year and track survival and movement
– Each banded Oystercatcher has a unique code engraved on a plastic band that can be read with binoculars or a spotting scope
Research Methods
Capture Methods • Adult oystercatchers are captured with a decoy and
noose carpet or a “Whoosh” net • Juveniles are captured just before fledging
AMOY noose trapping.mov
tracked with larger transmitters glued to a leg band
• Argos and GPS tags now feasible.
Reproductive Success • The breeding season is divided into
two distinct periods: nesting and chick rearing
• Oystercatcher chicks are mobile shortly after hatch and do not remain in the nest
• Nest survival is variable among sites and years, but is generally low; ~25% of all nests survive to hatch
• 0.39 (SE 0.02) chicks produced per breeding pair (n = 2,985 nesting attempts, 1995 – 2014)
Sources of Nest Failure During Incubation
Abandonment 6%
Human 3%
Storm/Tides 29%
Mammal 54%
Avian 5%
Ghost Crab 3%
Source of failure could not be determined for 52% of failed nests (N = 518)
N = 478
Chick Survival
• Oystercatcher chicks are camouflaged and highly mobile, which makes them difficult to monitor
• We used radio tags to track chicks and identify sources of mortality
Chicks Fledged per Breeding Pair
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014
Pr od
uc tiv
16% Environmental
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45
Days observed
C um
ul at
iv e
su rv
iv al
p ro
ba bi
lit y
N = 37
Source of mortality can not be determined for ~ 50% of chick mortalities
Schulte, S.A. and T.R. Simons. 2015. Factors affecting the reproductive success of American Oystercatchers (Haematopus palliatus) on the Outer Banks of North Carolina. Marine Ornithology 43: 37-47.
Vehicles and Chick Survival • Humans have direct and indirect
effects on chick survival • Oystercatcher chicks are highly
mobile • Small chicks use truck ruts and
beach debris for hiding • Fledglings collide with vehicles at
night • 13 chicks killed by vehicles on
Hatteras and Lookout from 2003- 2007
• Cape Lookout closed beach sections with oystercatcher broods after two chicks were killed in 2005
• No mortality from vehicles documented on CALO after the policy was implemented
Chick Survival and Vehicle Closures
0.267 0.476
Su rv
iv al
p ro
ba bi
lit y
Closure type
N=120
N=146
Daily survival rates (DSR) for American Oystercatcher broods on beaches with and without off-road vehicles.
0.91
0.92
0.93
0.94
0.95
0.96
0.97
0.98
0.99
1
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 Age (days)
D SR
Vehicles, Chick Behavior, and Habitat Use
Full beach closures
0.91
0.92
0.93
0.94
0.95
0.96
0.97
0.98
0.99
1
0 3 6 9 12 15 18 21 24 27 30 33 36 39 Age (days)
DS R
Forage access
No forage access
Hurricane Effects • Hurricane Isabel made landfall on the Outer Banks in 2003 • Overwash and sand movement improved habitat and
reduced predator populations • Large improvement in reproductive success in areas
affected by the storm
C hi
ck s
fle dg
ed /b
re ed
in g
pa ir
1998 2004
Demographic Model Insights • Hurricanes can have strong positive effects on nest survival • “Bonanza” years may be very important for population stability • Oystercatchers are long-lived birds, so a single strong cohort
can have long term effects on the population • Periodic depression of nest predator populations may be an
effective management tool for inducing bonanza years
Schulte and Simons. 2016. Waterbirds.
Predator Management • Gathered baseline data on the ecology
of raccoons South Core Banks in 2007 and 2008 – Population size – Home range size – Movement patterns – Population parameters
• Age distribution • Survival • Recruitment
• Evaluated the response of raccoon, shorebird, and turtle populations to an experimental removal of raccoons in 2008 - 2009
Parsons, A. W., T. R. Simons, A. F. O’Connell, Jr., and M. K. Stoskopf. 2012. Demographics, diet, movements, and survival of an isolated, unmanaged raccoon Procyon lotor (Procyonidae, Carnivora) population on the Outer Banks of North Carolina. Mammalia 77: 21–30.
Camera Trapping Results • Total of 1,299 camera
“captures” over 5 trapping periods from May 2007 to June 2008
• Total of 532 recaptures • Average population
estimate based on photo- recaptures over five camera-trapping periods = 228 animals (SE 20)
• Density ~ 10 raccoons per square mile
Parsons et al. 2015. Journal of Wildlife Management.
C hi
ck s
fle dg
ed p
er b
re ed
in g
pa ir 149 raccoons were trapped and
euthanized on South Core Banks in December 2008 and April 2009
Chicks Fledged per Breeding Pair
Effects of Human Disturbance
vehicles, and recreational activities affect the behavior, reproductive success, and survival rates of breeding American Oystercatchers on Cape Lookout National Seashore in 2011 and 2012
Methods: • Baseline audio monitoring of ground
noise level across the entire Park • 24-hour continuous audio and video
monitoring of American Oystercatcher nests (48,000 hours)
• Heart-rate monitoring of incubating individuals (12,000 hours)Borneman, T.E., E.T. Rose, and T.R. Simons. 2014. Minimal
changes in the heart rate of incubating American Oystercatchers (Haematopus palliatus) in response to human activity. The Condor 116: 493-503.
Behavior of American Oystercatchers Before and During Human Activities
* * * *
*
Table 1. Logistic exposure model exploring factors potentially affecting the daily survival rate of American Oystercatcher nests at North Core Banks, Cape Lookout National Seashore, USA, in 2010 and 2011 (n = 48). All factors evaluated were included in this model.
Explanatory variable Estimate (se) Z P-value Odds ratioa
(eEstimate)
Intercept Average daily aircraft events Average daily vehicle events Vehicle closureb
Nest-only None Drive-through Ramp
Within dunes
- 0.236 (0.740) - 0.319 0.750
Borneman, T.E., E.T. Rose, and T.R. Simons. 2016. Off-road vehicles affect nesting behavior and reproductive success of American Oystercatchers. Ibis 158: 261-78.
Limitations of Observational Studies - Lack of true replication, randomization, and controls
Behavioral and physiological responses of nesting American Oystercatchers to off-road vehicles on North Carolina’s National Seashores
Experimental Study 2014-2015
When vehicles are permitted to drive past American Oystercatcher nests
1)Does their incubation behavior change?
a)Do they spend less time on their nests?
b)Do they leave their nests more often?
c)Do they spend less time resting?
2)Does their physiology (heart rate) change?
Driving treatment
Do oystercatchers spend less time on their nests?
Does driving influence incubation behavior?
Do oystercatchers spend less time on their nests?
Does driving influence incubation behavior?
Do oystercatchers spend more time out of a head tucked position?
Does driving influence incubation behavior?
Do oystercatchers spend more time out of a head tucked position?
Does driving influence incubation behavior?
Do oystercatchers spend less time with their heads tucked?
Does driving influence incubation behavior?
Do oystercatchers leave their nests more often?
Does driving influence incubation behavior?
Do oystercatchers leave their nests more often?
Does driving influence heart rate?
2015 Results
2014 Results
2014 Results
Do these differences matter? Incubating American Oystercatchers…
• Stayed away from their nests for more time • Left their nests more frequently • Experienced reduced heart rates
Responses may diminish closer to hatching, and depend on time of day
Differences in heart rate, although statistically significant, are small, and there is considerable variation among individual birds
Do these observed differences influence demography?
Vehicles on Cape Hatteras
Implications for Management • Breeding population at CAHA has
declined nearly 50% in past 15 years • Multiple factors influence the
distribution, abundance, fecundity, and survival of AMOY on the Outer Banks
• Predation • Storms • Human Disturbance
• Birds are resilient and behavior is flexible, but they have limited tolerance of excess mortality of nests, chicks, and adults
• Population level goals can help clarify management trade-offs
The American Oystercatcher Working Group
• Research on American Oystercatchers in Virginia was pioneered by E. Nol in the 1980’s and summarized in her 1994 BNA account with R. Humphrey
• New research began on the Outer Banks of North Carolina in 1995. Additional research projects were initiated in Georgia and South Carolina in 2000.
• Interested biologists met at the Waterbird Society Meeting in 2001 and agreed to create an informal working group
• Research initiated in Virginia in 2002, and in MA and NJ in 2004. Today 30+ institutions and organizations participate
• Working Group meetings have been held annually since 2001 at study sites between Maine and Texas
• 2016 National Conservation Award from the USFWS
NFWF Focal Species Initiative
• In 2008 working group members developed a 10 year business plan to promote the conservation of American Oystercatchers through a National Fish and Wildlife Foundation focal species initiative
• The resulting program provided $5 million in direct and $4.2 million in matching funds to support dozens of research and management projects conducted by working group members along the Atlantic and Gulf Coasts
Working Group Affiliations • Barataria-Terrebonne National Estuary Program • Clemson University • College of William and Mary • City University of New York • Delaware Division of Fish and Wildlife • Florida Game and Freshwater Fish Commission • Georgia Department of Natural Resources • Gulf Coast Bird Observatory • Louisiana Audubon • Manomet Center for Conservation Sciences • Maryland Department of Natural Resources • Massachusetts Audubon • Massachusetts Division of Fish and Wildlife • National Audubon Society • National Park Service • New Jersey Audubon • New Jersey Division of Fish and Wildlife • New York City Audubon • New York City Parks and Recreation • North Carolina Audubon • North Carolina State University • North Carolina Wildlife Resources Commission • Rutgers University • South Carolina DNR • Texas State University • Texas A&M • The Nature Conservancy • Trent University • University of Georgia • University of Houston • U.S. Fish and Wildlife Service • U.S. Geological Survey • Virginia Department of Game and Inland Fisheries • Wildlife Conservation Society
Working Group Web Page http://amoywg.org
• A Working Group Web page created in 2002 provides: – A summary of Working
Group objectives, activities, and contact information
– Access to the Working Group list serve with >150 members
– Banding protocols, banding summaries by state, banded bird reporting form
– Descriptions of field methods
Introduction: Erica Nol , Trent University Characteristics: Tracy Borneman, NCSU Coop.Unit, Distribution: Janell Brush, Florida Fish and Wildlife Conservation Commission Systematics: Theodore R. Simons, USGS NCSU Coop. Unit Migration: Shiloh Schulte, Manomet Center for Conservation Science Habitat: Jessica Stocking, NCSU Coop. Unit Food Habits: Jon Altman, National Park Service Sounds: Pam Denmon, U.S. Fish and Wildlife Service Behavior: Alex Wilke, The Nature Conservancy Breeding: Tom Virzi, Rutgers University Demography and Populations: Conor McGowan, Alabama Coop. Unit Conservation: Brad Winn, Manomet Center for Conservation Science Appearance: Sara Schweitzer, North Carolina Wildlife Resources Commission Measurements: Kim Peters, Massachusetts Audubon Future Research: Stephen Brown, Manomet Center for Conservation Science American Oystercatcher Working Group: Ruth Boettcher, Virginia Dept. of Game References: Sue Heath, Gulf Coast Bird Observatory
Other Contributors:
Robert C. Humphrey (RH), Brunswick Maine. Sean Murphy, USGS Forest and Rangeland Ecosystem Science Center Felicia Sanders, South Carolina Department of Natural Resources
American Oystercatcher Working Group. 2012. American Oystercatcher (Haematopus palliatus), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology.
• ~4,000 birds marked with dual alpha- numeric bands color-coded by state, >41,000 resights
• Winter re-sights of American Oystercatchers banded during the breeding season (map)
• Northern breeders appear to make longer movements
• Pairs show strong mate and nest site fidelity
• Winter movements of nearly ~4,000 km documented (Cape Lookout, NC to Laguna de T’erminos, Campeche, Mexico, Oct. 2013), 2015 Pacific Coast of Nicaragua and Honduras
• Generally strong connections between natal sites and nest sites for first-time nesters but some long dispersals documented
• Age at first breeding 3-5 years
Mark-resight Studies
Resighted, October 2013
• >41,000 Records for ~4,000 individual AMOY
• Reports from Maine to Mexico, 758 unique observers, 81 Working Group members
• Secure, fully searchable • Includes >1,300 photos and
Google Earth mapping capability
US Population - Winter Roost Surveys • Aerial surveys from NJ to TX Winter
2003 and NY to TX Winter 2013 • Stratified sampling, 239 blocks • High tide +/- 2 hours survey window • Detection rates calculated from digital
photographs and ground truth surveys – Detection rate 0.73 for flocks <50
birds – Detection rate 1.0 for flocks > 50
birds
Brown et al. 2005. Journal of Wildlife Management 69: 1538-1545.
Year Estimate S.E.
2003 10,971 298
2013 11,284 313
# Birds banded
New Hampshire 0
Connecticut 55 0 No S. Schulte 20141
New York 76 35 Yes S. Elbin 20152
New Jersey 400 339 75-150 No Yes T. Pover 20152
Delaware 15 24 Yes M. Bailey 20141
Maryland 108 2 Yes Traut et al. 2006
Virginia 730 267 100-400 No Yes Wilke et al. 20072
North Carolina 325 321 50-100 No Yes S. Schweitzer 20152
South Carolina 400 324 20-40 Yes Yes Sanders et al. 20082
Georgia 120 167 10-50 Yes Yes T. Keyes 20152
Florida 272 103 120-280 No Yes J. Brush 20152
Alabama 15 0 Yes Zdravkovic et al. 2006
Mississippi 25 0 Yes Zdravkovic et al. 2006
Louisiana 120 43 Yes E. Johnson 20152
Texas 170 295 50-90 No Yes S. Heath 20152
Total 3064 3970
Demographic modeling of range-wide fecundity and survival estimates
Linking to
Juvenile survival
With
5,815
Hemispheric conservation efforts
• Refine range-wide monitoring methods to reduce survey bias associated with variations in sampling effort and detection probability
• Expand citizen science and outreach
• Measure range-wide changes in distribution, abundance, and productivity
• Relate these metapopulation dynamics to changes in habitat use and availability
Thanks! The American Oystercatcher Working is comprised of over 30 institutions and organizations including; Barataria-Terrebonne National Estuary Program, Clemson University, College of William and Mary, City University of New York, Delaware Division of Fish and Wildlife, Florida Game and Freshwater Fish Commission, Georgia Department of Natural Resources, Gulf Coast Bird Observatory, Louisiana Audubon, Manomet Center for Conservation Sciences, Maryland Department of Natural Resources, Massachusetts Audubon, Massachusetts Division of Fish and Wildlife, National Audubon Society, National Park Service, New Jersey Audubon, New Jersey Division of Fish and Wildlife, New York City Audubon, New York City Parks and Recreation, North Carolina Audubon, North Carolina State University, North Carolina Wildlife Resources Commission , Rutgers University, South Carolina DNR, Texas State University, Texas A&M , The Nature Conservancy, Trent University , University of Georgia , University of Houston, U.S. Fish and Wildlife Service, U.S. Geological Survey, Virginia Department of Game and Inland Fisheries, and the Wildlife Conservation Society. I also thank; M. Bailey, J. Brush, R. Boettcher, R. DeMay, S. Elbin, S. Felton, S. Heath, N. Hostetter, E. Johnson, T. Keyes, D. LeBlanc, C. Mostello, T. Pover, S. Melvin, F. Sanders, S. Schulte, S. Schweitzer, S. Sinkevitch, S. Stanley, and A. Wilke for their individual contributions to this presentation.
Students Melissa Davis Conor McGowan Shiloh Schulte Arielle Parsons Jessica Stocking Tracy Borneman Eli Rose Nathan Hostetter Shilo Felton
Biology and Conservation of American Oystercatchers on the Outer Banks of North Carolina - 20 years of collaborative focal species research and management
Outline
Slide Number 8
Slide Number 9
Focal Species Conservation
Chick Survival
Sources of Chick Mortality
Vehicles and Chick Survival
Chick Survival and Vehicle Closures
Daily survival rates (DSR) for American Oystercatcher broods on beaches with and without off-road vehicles.
Vehicles, Chick Behavior, and Habitat Use
Chick Survival - Access to Foraging Sites
Slide Number 30
Slide Number 42
Slide Number 43
Slide Number 44
Slide Number 45
Slide Number 46
Slide Number 47
Slide Number 48
Slide Number 49
Slide Number 50
Slide Number 51
Slide Number 52
Slide Number 53
Slide Number 54
Slide Number 55
Slide Number 56
Slide Number 57
Slide Number 58
Slide Number 59
Slide Number 60
Slide Number 61
Slide Number 62
Slide Number 63
Slide Number 64
Slide Number 65
Implications for Management
NFWF Focal Species Initiative
AMOY BNA Account Revision
Banding and Productivity Monitoring