A study led by the University of Minnesota sheds new light on the impact of humans on wolf populations in national parks. Researchers have found that human-caused mortality triggers instability among wolf packs. In particular, the team found that human activities such as trapping and legal hunting have adverse effects on reproduction and pack persistence among gray wolf populations.
“Gray wolf management is rarely straightforward, and transboundary wildlife issues are complicated by disparate management objectives,” the researchers wrote. “Despite our study of gray wolves that lived primarily in national parks and reserves, we documented high levels of human-caused mortality, most of which occurred outside protected area boundaries. , these mortalities had adverse effects on biological processes at the level of the gray wolf pack.
The team analyzed decades of data on packs of gray wolves living primarily in Denali National Park and Preserve, Grand Teton National Park, Voyageurs National Park, Yellowstone National Park and Rivers National Preserve. Yukon-Charley. The study, led by Kira Cassidy, a research associate at Yellowstone, was conducted in collaboration with experts from the five national parks and the Voyageurs Wolf Project at the University of Minnesota.
“For gray wolves, the biological unit is the pack or the family. We wanted to focus on the impacts of human-caused mortality on the pack, a metric on a finer scale than population size or growth rate,” Cassidy said. “We found the odds of a pack persisting and reproducing declines with more human-caused mortalities.”
To investigate, the researchers examined packs of wolves after at least one member had been killed by human causes and compared these groups with packs that had not experienced human-caused mortality.
The study found that the likelihood of a pack staying together until the end of the year decreased by 27% after human-caused mortality, while the reproductive rate dropped by 22%. The impacts were even more severe when a pack leader died, with the pack’s chance of persistence decreasing by 73% and reproduction decreasing by 49%.
Wolves in Voyageurs National Park spent the most time outside park boundaries. As a result, 50% of all deaths among this population were attributable to humans, and poaching was the predominant cause.
“The unique shape of the Travelers means that there are very few wolf packs that live entirely within the boundaries of the park. Instead, many wolf pack territories straddle the park boundary and when wolves leave the park they are at increased risk of being killed by humans,” said study co-author, Thomas Gables.
“Rather than viewing this result as a failure, we hope this work will encourage renewed interest in inter-agency collaboration, where gray wolf management is defined by compromise and based on science, including the weighted space utilization and cause-specific mortality data,” the study authors concluded. “If efforts are made to achieve this goal, these protected areas and the partners involved can serve as a model for successful transboundary issues around the world.”
The study is published in the journal Borders of ecology and environment.
Through Chrissy Sexon, Terre.com Personal editor
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