A project of Craighead Beringia South in conjunction with the partners and sponsors detailed below.
|Name||Species||Life Stage||Release Date||Last Location||Days Transmitted|
|Wally||Bald Eagle||1 year-old||2009-11-13||2011-10-11||697|
|Eagle Formerly Known as 44828||Bald Eagle||Adult||2009-11-29||2010-04-10||132|
|Dapper Dan||Bald Eagle||hatch-year||2009-12-09||2012-01-31||783|
Click on an animal's name for maps and more information.
In 1992, the first captive bred California Condors were re-introduced back in the wild after a period of extinction. Several years later, a trend of condors becoming ill and dying was documented with what was later determined to be lead poisoning. After an intensive investigation, the lead source was traced to spent rifle ammunition left behind by hunters in either offal (gut piles) from harvested animals or un-retrieved game. Since then, the hazards of lead from spent rifle ammunition on scavenging birds have been widely documented across the globe and a broader understanding of its effects is understood. Several studies, including the one in Jackson Hole by Craighead Beringia South (CBS), have found that an average of 160 lead fragments are left in the offal that is fed upon by scavengers.
In 2004, CBS began a study to assess the potential impact of spent lead rifle ammunition on wildlife in Jackson Hole, Wyoming, particularly targeting ravens. Jackson Hole is an ideal location to examine the relationship between lead and scavenging birds due to the large number of elk, and now bison, harvested each year and the extremely large population of ravens in this valley. Since the beginning of the study, biologists with CBS have captured and tested blood lead levels of 600 ravens and expanded the project to also examine the effect of lead on both bald and golden eagles that either call Jackson Hole home or migrate to the area from afar. We have documented consistent significant spikes in the blood lead levels of ravens and eagles during the hunting season, with some values confirmed as high as 718 µg/dL. Critical levels effecting survival of bald eagles have been documented at 100µg/dL. Our previous results have further documented that the annual blood lead levels of ravens within the valley can accurately be predicted by the number of elk and bison harvested.
The 2009 hunting season marked the first year of satellite tracking bald ealges in Jackson Hole. The main objective of this aspect of the study was to estimate the proportion of local and migratory bald eagles in the valley during the hunt. It is possible that many eagles are attracted to the area every fall to scavenge the offal and unretrieved carcasses left in the field by hunters and in so doing are ingesting lead in Jackson Hole. Consequently, local hunting practices and management would have regional or national effects. If this local source of poisoning is negatively effecting birds that reside in other locations to the point of morbidity, then impacts on eagle populations throughout the west could be effected by either lowering the total population size (i.e. birds being killed by lead) , reducing their ability to reproduce viable offspring, and/or reducing reproductive output. Further, if the eagles have an amount of lead that is so toxic it causes death, scavengers that ingest the carcass of the poisoned birds would ingest that lead and it would continue impacting animals down the food chain. By obtaining a general idea on what proportion of the birds are local versus migrants, we can better understand the issue and the scope of the potential dangers of lead rifle bullets.
Phase one of this project was to determine the potential impact of spent lead rifle ammunition on ravens and eagles in the valley. With evidence documenting an increase of lead in both ravens and eagles during the hunting season, phase two is to determine a way to mitigate this problem. Luckily, there are practical alternatives to lead bullets most commonly used by hunters; solid copper or gliding metal bullets. These lead-free bullets are made by a variety of manufacturers and have been proven effective, both balistically and in the field. Beginning in 2009, we began distributing this non-lead ammunition to hunters, free of charge, to help jump start a shift by hunters from the traditional lead bullets to the non-lead alternatives.
This project is logistically and financially supported by Grand Teton National Park, the National Elk Refuge, 1% for the Tetons, the Peregrine Fund, EcoTour Adventures, and a variety of private individuals and foundations.
Craighead Beringia South is a non-profit science and educational organization established in 1998. Located in Kelly, Wyoming, CBS is sandwiched between the National Elk Refuge and Grand Teton National Park and lies at the geographical hub of the Jackson Hole valley, in the southern half of the Greater Yellowstone Ecosystem. As a private, not-for-profit (501[c]3) organization, it is supported by the private sector and its unique research approach affords flexibility, continuity and a creative intellectual environment.
The mission of Craighead Beringia South is to contribute new knowledge toward improving the management and conservation of our natural environment by pursuing innovative, long-term field investigations on key ecosystem components upon which all life depends.