Gulf Coast Bird Observatory
Linking the Land Birds and People of the Gulf of Mexico
Region
Fall Migration of Raptors – Kites,
Hawks, Eagles, Falcons, and Vultures
Values of Raptor Migration Monitoring
� Counts are efficient, cost-effective method of docu menting regional population trends for multiple species.
� Banding enables tracking studies to delineate migra tory flyways, identify source populations, and document causes of mortality.
� Banding enables health monitoring as well as large- sample studies of basic biology, physiology, and morpholog y.
� Contributes to understanding of migratory ecology.
� Provides superb opportunities to engage the public and promote grass-roots conservation.
Primary Long -Term Raptor Migration
Monitoring Sites inWestern N.A.
Mt. Lorette, ALB
Chelan Ridge, WA
Bonney Butte, OR
Marin Headlands, CA
Kern River Valley, CA
Boise Ridge, IDBridger Mts., MT
Goshute Mts., NVWellsville Mts., UT
Commissary Ridge, WY
GrandCanyon, AZ Sandia &
Manzano Mts., NM
Veracruz, MEX
Corpus Christi, TX
Smith Point, TX
Time frames8-30 years
Managed or co-sponsoredby HawkWatch International
Other organizations
Banding Sites
Dinosaur Ridge, CO
Hawk Ridge, MN
Autumn Routes and Patterns
Continental Geography of Raptor Migration in N.A.Migration Monitoring Network
Primary Concentration PointsLong N-S mountain rangesCoastlines & major lakeshoresMajor river corridorsMajor peninsulas
Commissary Ridge, WYChelan Ridge, WA
Goshute Mountains, NV Bridger Mountains, MT
WellsvilleMountains
UT
Remote Ridge-topSites in the West
Use of Wind -Driven UpdraftsBy Migrating Raptors
wind
As winds collide with the ridge they are deflected upward. Migrating raptors ‘surf’ along these updrafts, proceeding along their way with minimal effort.
Use of Thermal UpdraftsBy Migrating Raptors As the sun heats
the ground, the air above it warms and rises. Migrating raptors effortlessly circle up on these thermal updrafts until they dissipate, then they glide down and catch another thermal, and start the process again.
Corpus Christi, Texas
Smith Point, Texas
‘Easy Life ’On the Gulf Coast
Veracruz, Mexico
Coastline/continental funnelBirds rely on thermal lift
- “kettling” then streaming Variable flight lines
Smith Point Raptor Migration Study
Smith Point
Corpus Christi, TX- US largest flights
Veracruz, Mexico- world’s largest
flights
Gulf Coast Continental Migratory Funnel
Swainson’s HawkMississippi Kite
Broad-wingedHawk
Turkey Vulture
Texas / Veracruz“Superflockers ”
0
10
20
30
40
50
60
70
80
08/17-08/21
08/27-08/31
09/06-09/10
09/16-09/20
09/26-09/30
10/06-10/10
10/16-10/20
10/26-10/30
11/05-11/09
11/15-11/19
Five-day period
Per
cent
of t
otal
cou
nt
1992-1996 mean +/- 95% CI 1999
VeracruzBroad -winged Hawk Fall Activity Pattern
Autumn Daily Rhythm of Migration - Texas
Corpus Christi
0
5
10
15
20
25
30
700
800
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
Hour of the Day
% o
f tot
al c
ount
Smith Point
05
101520253035
600
700
800
900
1000
1100
1200
1300
1400
1500
1600
Hour of the Day
% o
f tot
al c
ount
Values = 1997-2001 mean ± SD
Gulf CoastSpecialties
Harris’ Hawk
Mississippi Kite
Aplomado Falcon
Crested CaracaraWhite-tailed Hawk
Swallow-tailedKite
15,101
11,100
3,645
5,180
2,718 2,576
27,555
59,237
731,94116,287
4,477,057
18,41354,291
68,183
73,776
3,868
~5,000
21,133
Magnitude of Migration at Selected Watchsites
AutumnAll Raptors
HWI Band -Returns and Associated
Western Flyways
Hoffman et al. 2002J. Raptor Research
Satellite Tracking ProgramObjectives
� Improve understanding of migration dynamics
� Identify conservationneeds
� Delineate migratory flyways� Identify migrant source populations� Quantify flyway and territory fidelity
Golden EagleSatellite Tracking2002-2003
Collaborative project begun in 2003 to:1) Develop/maintain continental database and
web-based data entry/access system.2) Produce statistically robust indices of annual
abundance and long-term demographic trends.3) Provide frequently updated, scientifically sound
assessments of the status of migratory raptors.4) Make this information widely available to
participating raptor-migration monitoring sites, the scientific community, conservation and wildlife management agencies, and the public.
The Raptor Population Index (RPI) ProjectA Model Effort to Facilitate Continental-Scale Rapt or Migration
Monitoring and Tracking of Population Trends
HMANA / RPIDatabase System
www.hawkcount.org� Password protected for data entry
and site-profile development� Public-accessible for general
information and data summaries� Redundant back-up system for
secure, long-term data archiving � Rigorous data-use policy for
professional and scientific use according to site preferences
� Linkages with other major avian databases; e.g., Avian Knowledge Network
>5 million records>200 watchsites registered
http://rpi-project.org�Standardized data-collection
protocols
�RPI trend results
�Site-specific, regional, and continental status & trends reports
�Status & trends information packaged for export to participating sites
� In 2010: ability to conduct customized trend analyses on-line, similar to current capabilities of Canadian Migration Monitoring Network and U.S. Breeding Bird Survey
� First major RPI status & trends product� Published June 2008
� Application of new analytical approach� Chapter on migration geography
� Watchsite profiles� Continental autumn migration trends:
1974-2005
� Species-specific conservation status reports
State of North America ’s Birds of Prey
Available at http://www.buteobooks.com - limited supply!
Population Trend
Significant* Increase
Significant Decrease
Non-significant Increase
Non-significant Decrease
*P < 0.05
Trend Magnitude Flight Magnitude
| |trend| < 1 <100/yr
| 1 < |trend| < 5 100-1000/yr
| |trend| > 5 >1000/yr
b
a
a 1997-2005 b 1998-2005 c 1999-2005
a
a
c
American KestrelNortheast Migration Counts1974-2004: -1.6 to -4.5% per yr1994-2004: -3.3 to -8.5% per yrBBS 1976-2003: -1.4%/yrCBC 1976-2003: NE -4.6%/yr, SE -1.4%/yr
Western Migration Counts1980’s-2005: mixed trends1995-2005: -5.9 to -8.6%/yrBBS 1985-2005: -1.7 to -2.7%/yrCBC 1985-2005: -1.5 to -2.5%/yr
Gulf Coast Migration Counts1995-2005: stable to declining (FL)BBS 1995-2005: -0.2%/yrCBC 1995-2005: SE -1.4%/yr
from State of NA’s Birds of Prey (2008)
Migration SiteEducation
Thrill of the Release!!