Hawks, like many other wild birds, are banded for several important reasons. Banding provides valuable information that helps conservationists track and protect raptor populations. The leg bands allow individual birds to be identified if they are encountered again. From this, researchers can determine migration routes, lifespan, population numbers, causes of mortality, and more. Banding hawks and other raptors has helped shape our understanding of these magnificent birds of prey.
Why Band Birds?
Bird banding serves many purposes:
Identification
The numbered metal or plastic leg bands provide each bird with a unique identifier. This allows researchers to recognize individual birds when they are captured, observed, or found dead. The band numbers can be traced back to the place and date the bird was originally banded.
Survival and Longevity
Encounters with banded birds over multiple years provide information on survival rates and longevity. Banding data helps determine average and maximum lifespan for different species. For example, the oldest known wild Red-tailed Hawk was over 28 years old and the oldest captive Ferruginous Hawk lived to be 32.
Territory and Migration
Seeing where banded birds are encountered over time maps out the territory, migration routes, and dispersal patterns of populations. Banding shows precisely where birds go throughout the annual cycle. For instance, researchers have learned that Swainson’s Hawks migrate all the way to Argentina for the winter.
Population Dynamics
Because each marked bird represents a known percentage of the whole population, banding reveals population estimates, numbers, and changes over time. Capturing and banding hawks across their breeding and wintering grounds provides demographic data to inform conservation efforts.
Mortality Causes
Bands recovered from deceased hawks help determine major sources of mortality. For example, studies of banded Red-tailed Hawks have shown that collisions with vehicles and windows are significant causes of death. Analysis of banding and recovery data identifies dangers to raptors and guides efforts to reduce unnatural causes of death.
Behavior and Ecology
Tracking banded birds expands knowledge of raptor behavior and ecology. Banding reveals insights into habitat use, home ranges, foraging patterns, interspecies interactions, breeding biology, and much more. This information further deepens understanding of the natural history of hawks.
Banding Techniques
Banding most raptors requires specialized techniques, given the birds’ powerful talons and sharp beaks. Safely capturing hawks for banding takes specific methods and skills. Here are some of the main techniques:
Nest Banding
Many hawks are banded while still nestlings, before they are able to fly. Climbers carefully remove chicks from the nest to band them on the ground or in bags. Nest banding provides early identification and minimizes potential harm to young birds learning to fly.
Noose Traps
Often used at nest sites, noose traps (known as bal-chatri traps) employ nooses made of fishing line or hair to catch a hawk’s legs when they strike at a live lure like a mouse or rabbit. Trapped hawks are then removed and banded.
Net Traps
Various net traps are used to passively capture hawks, including dho-gaza nets, bow nets, and mist nets. These fine nets are staked out and birds fly into them and become entangled. The hawks are then carefully removed for banding.
Bownet Traps
Bownets utilize a rectangular net stretched between upright poles. When a hawk is lured between the poles after prey, the net is released via a trigger mechanism, safely capturing the hawk.
Falconry
Increasingly, falconers will capture passage hawks such as Peregrines or Merlins with trained hawks. The wild hawks are safely restrained and banded before being released.
Banding Hawks
Banding most hawks takes specialized experience and techniques. Safety of the birds is paramount. Here is an overview of the basic banding process:
Capture
The hawk is captured using one or more of the methods described above. Care is taken to restrain the wings and legs to avoid injury.
Processing
The hawk’s age, sex, weight, wing length, body condition, and molt are documented. Photos may be taken as well. Samples of blood or feathers may also be collected.
Banding
A numbered aluminum band, often colored for specific projects, is placed on one leg. Additional bands may be added to the other leg for identification at a distance.
Release
The hawk is carefully released at the site of capture. Banders avoid keeping birds for excessive time periods to minimize stress.
Reporting
The banding data is reported to the federal bird banding lab to be added to research databases. Band numbers are recorded so re-encounters can provide further data.
Major Hawk Banding Programs
Many research groups and agencies conduct hawk banding across North America. Some of the most significant efforts include:
Hawk Migration Association of North America (HMANA)
A network of researchers bands hawks at migration hotspots. Tens of thousands of hawks are banded at sites like Hawk Ridge and Holiday Beach to study timing, routes, demographics, and populations.
HawkWatch International
Focused on western North America, this group bands hawks to assess populations, productivity, survival, movements, and threats. Target species include Red-tailed Hawks, Ferruginous Hawks, Swainson’s Hawks, and others.
Midwest Peregrine Society
Dedicated volunteers capture and band migrant Peregrines in the Midwest to better understand the peregrine population recovery and post-fledging dispersal behaviors.
USGS Bird Banding Laboratory
This federal lab manages banding data for all bird species in North America. Over 70 million banding records allow broad research and analysis of avian populations.
| Program | Location | Key Species | Banding Focus |
|---|---|---|---|
| HMANA | Migration Sites | Broad-winged Hawk | Migration Timing and Routes |
| HawkWatch International | Western North America | Red-tailed Hawk | Breeding Populations |
| Midwest Peregrine Society | Midwestern United States | Peregrine Falcon | Dispersal and Migration |
| Bird Banding Laboratory | North America | All Species | Broad Research |
Notable Discoveries from Hawk Banding
Banding hawks has led to many groundbreaking discoveries about their biology and ecology:
Extensive Migration Routes
Band returns documented the full extent of migration routes, including a Swainson’s Hawk migrating over 12,000 miles round trip each year between North America and Argentina.
Juvenile Dispersal
Banding nestlings revealed surprising distances and directions of first migration flights, critical data for understanding meta-population dynamics.
Extreme Longevity
A wild female Red-tailed Hawk banded in New York was recovered over 28 years later, setting a longevity record. Captive birds have lived even longer.
Mortality Causes
Analysis of bands found hawks killed showed dangers posed by rodenticides, lead poisoning, electrocution on power lines, window strikes, and more. Identifying hazards helps protect raptors.
Declining Populations
Banding data from migration counts detected troubling declines in many species, spurring expanded conservation measures before it was too late.
Effective Conservation
Marked increases in banded Peregrines demonstrated the success of DDT bans and captive breeding programs for this endangered falcon.
Importance of Public Reports
The public plays a key role in the success of hawk banding studies by reporting encounters with marked birds. There are several ways for the public to report hawk bands:
Call Band Reporting Hotlines
Band reporting hotlines are staffed by knowledgeable operators who collect key details. In the US and Canada, call 1-800-327-BAND or report online at reportband.gov.
Notify Banding Groups
Many banding organizations provide contact info on their websites for reporting re-sightings of their banded raptors. Search online for relevant groups.
Note the Band Numbers
Carefully note all digits and letters on the band so the unique identifier can be traced by researchers. Also document the location and date.
Take Photos
Photos and videos help verify bands and show important details like activities, molt patterns, or habitats. Get images from all angles possible.
Public band reports expand the data available to better understand hawk populations. Even single encounters provide valuable insights that can advance raptor research and conservation.
Conclusion
Banding programs have shaped modern understanding of hawks while providing important population monitoring tools. The marked birds yield valuable life history data over time through public sightings, recaptures, and recoveries. Banding has identified hazards raptors face and informed effective protection efforts. While requiring specialized techniques, banding hawks humanely is vital for tracking reproduction, survival, movements, and more to guide science-based management. Public participation through reporting banded hawk observations makes a real contribution to conserving these iconic predators. Though some challenges remain, banding will continue playing a crucial role in the future research and conservation of hawks and other birds of prey.
