Darted Grizzly Bear Yearling Died From Internal Bleeding

Date: August 24, 2009
Contact: Amy Vanderbilt, 406-888-5838
Contact: Wade Muehlhof, 406-888-7895

WEST GLACIER, MONT. - A necropsy (animal autopsy) determined that the grizzly bear yearling that died after being darted by park rangers on Monday August 17, 2009, died from internal bleeding. The results show the bear did not die from the initial darting, but from a subsequent laceration of the jugular vein. The necropsy was not able to determine exactly how the vein was ruptured. The necropsy was performed by Jennifer Ramsey, Wildlife Veterinarian with Montana Fish, Wildlife & Parks.


Necropsy findings indicate that the bear cub died of acute hemorrhage. The finding of large amounts of clotted blood, along with evidence of the body’s response to acute blood loss (empty heart, pale grey liver, contracted spleen) support this diagnosis. Although the initial wound created by the dart was close to the jugular vein, it did not appear to hit it directly. Two possibilities exist that may have resulted in the laceration of the jugular vein. First, because of its proximity to the right humerus, the dart would have been likely to move around as the bear walked. This motion may have been what allowed the sharp dart tip to lacerate the jugular vein. Another possibility to consider is that the force of the drug being expelled from the dart under pressure tore the jugular vein.


The yearling was darted as part of a bear management action to remove a 17-year-old female grizzly from the park after bear management rangers determined her to be conditioned to humans. After the female was removed on August 17, 2009, rangers darted and tranquilized her two yearlings. One cub died shortly after being tranquilized. Rangers attempted to resuscitate the yearling by performing mouth-to-nose CPR, but to no avail.


The carcass is that of a yearling male grizzly bear (Ursus arctos) from Oldman Lake, Glacier National Park. This cub was caught in a snare on July 28. He was chemically immobilized with Telazol, and recovered uneventfully. On August 17 the sow had to be humanely dispatched because she posed a threat to human safety. This male cub and his sibling were both darted with Telazol. When field personnel approached this cub, they determined that he was not breathing sufficiently but still had detectable heart beat. The biologist quickly began resuscitation efforts, however the cub did not respond and died shortly thereafter.


Glacier National Park Superintendent Chas Cartwright says “The unintended death of this yearling grizzly is a very unfortunate outcome of a very difficult operation.” Glacier National Park’s internationally-vetted Bear Management Plan and Guidelines specifies that conditioned bears that display over familiarity must be removed from the wild population. The U.S. Fish and Wildlife Service oversees and coordinates the transfer of captive grizzlies to federally-authorized zoos and captive facilities, none of which were willing to take an adult bear. Final details are still being worked out to transfer the other yearling to the Bronx Zoo in New York.


Glacier National Park’s Bear Management Plan and Guidelines are dynamic management tools that receive periodic international peer review. As a protected species under the Endangered Species Act, the decision to remove the family of grizzlies was not taken lightly, but was the result of Glacier’s ongoing coordination with the USFWS, the agency charged with administering the Endangered Species Act.


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