We are very grateful for the hard-working volunteers who assist Dr. Peter Bloom in the field, especially on research projects associated with his non-profit, Bloom Research Inc. Below is an article written by long-time volunteer and raptor bander, Hal Batzloff, published in the Eastern Sierra Audubon’s newsletter earlier this month:
By Hal Batzloff
Banding and tagging birds of prey provides invaluable information relative to population status, productivity, natal dispersal, territory fidelity and migration. And field research is the lifeblood of this science. For those of us involved in studying these wonderful birds of prey, field work is a yearlong activity. Long before nestlings are ready to band in the spring and summer we spend countless hours surveying historical and potential new territories. The survey work we do helps us answer many questions: Have historical nest sites survived? Can we discover new sites? Will the nests be used by raptors and if so, what species? When are birds pairing up? When are females brooding? And lastly, do the nests contain nestlings, of what age, and are the nest sites accessible enabling us to band the young? We have just finished our preliminary survey work on nesting territories that include Red-tailed Hawks and Great Horned Owls. We will be looking in February to March for activity at these nest sites and April to May to band nestlings. Swainson’s Hawk nestlings are banded in early July as adults arrive from their wintering sites in Argentina in March.
I’m a volunteer field biologist for Bloom Research, Inc (bloomresearch.org), a non-profit organization founded by world-renowned raptor scientist, Dr. Peter Bloom. Pete has been banding and studying birds of prey for 50 years and has banded over 35,000 raptors including over 800 Golden Eagles. He has been a prolific writer and has published scientific papers on nearly every species of raptor in California. He captured all of the remaining free flying wild California Condors in the 1980’s that would become breeding stock for their eventual successful reintroduction into the wild. He has been studying and banding raptors in the Owens Valley since the 1970’s. Our main emphasis currently in the Owens Valley is on Red-tailed Hawks and Swainson’s Hawks. He also bands Osprey nestlings at Mono Lake each summer in partnership with the California State Parks. There is a great video produced by the Parks people of this research on the Bloom Research website: OSPREYS AT MONO LAKE - A CONSERVATION STORY
Banding of nestlings in spring and summer is only the beginning of data gathering for raptor scientists interested in the movement of these birds as juveniles and adults. Recovery of band data through resighting and recapture is the linchpin that helps us link data from the initial banding. In addition to movement, recapture provides data on weight, general health, maturity, molt and genetics. Metal bands from the U.S. Geological Survey’s Bird Banding Laboratory are placed on all raptors and those birds that are of specific scientific interest to us receive a color band on the opposing leg. Currently, those birds are Red-tailed Hawk, Red Shouldered Hawk and Swainson’s Hawk. This color band has a two character letter/number sequence that is readable in the field with good quality optics and cameras. The photo shows an eight week old fledged Swainson’s Hawk with a perfectly positioned readable color band.
Fledgling Swainson's Hawk with a color band. This would be reported as “A8”. (Photo Credit: Hal Batzloff)
These band numbers can be reported at the USGS Bird Banding Laboratory. The online form is easy to complete by providing basic information such as species, band number, date and location. You will receive a certificate from the Bird Banding Lab (BBL) with data indicating where and when the bird was originally banded and by whom. Once your report is in the BBL’s database the data becomes available for scientific inquiry to raptor scientists worldwide.
[Additional information about the use of color bands: Color bands are used as a visual aid to make identification easier from a distance. From far away and in certain lighting conditions, it can be very difficult to read the 8 or 9-digit sequence of small numbers on the imprinted metal USGS bands, even with a high-powered scope or telescopic camera lens. The color bands, with a larger and simpler 2-digit code, often provide a quicker way to identify the raptor without the stress of recapturing it. These types of color bands require additional permitting from USGS and are included on Bloom’s federal master bander permit.]
More about Hal:
From a letter of recognition for achievement in partnership with Inyo National Forest (USFS), Bishop Bureau of Land Management, and Partners in Flight:
Hal Batzloff leads Dr. Bloom’s Owen Valley field work. Hal annually accomplishes nesting surveys and leads raptor captures and banding of migratory and resident raptors across Owens Valley. This has resulted in an incredible amount of new shared data and has strengthen the knowledge between wildlife managers, researchers and local ornithologists. Dr. Bloom’s extensive publications from these data is among the best available science that are essential to land managers decision making and extremely relevant because it has local significance. The wealth of knowledge this team provides to land managers includes bird identification, habitat management recommendations, and valuable connections with managers from important areas such as critical migration stop overs (Salt Lake City, Mono Lake, Copper River Delta, etc). This partnership has allowed public land managers to realize the value of the fly way Owens Valley provides for migrating avian species and has triggered partnerships across state and international borders. Managing critical elements important to raptors must include all stop overs so that migrations can be successful and support future populations. As a result of this partnership it has stimulated communications with other land managers across far away and international borders where numerous raptors visiting Owens Valley migrate from, like Argentina, Alaska, and Central America. As a direct result of this volunteer, the Inyo NF database for nest trees and territories has increased allowing biologist to better mitigate activities and contribute directly to conservation efforts that protect critical life stages for these visiting and resident raptors.