The BLM uses a helicopter to gather mustangs during a 2017 gather operation in the Bible Springs Complex, in Southern Utah. | Photo: iStock

Animal deaths, both natural and resulting from humane euthanasia, related to helicopter roundups of feral equids occur at a similar rate as deaths related to bait-trapping—another method used to gather wild horses—said John Derek Scasta, PhD, of the University of Wyoming’s Department of Ecosystem Science and Management, in Laramie. In either scenario, the death rate is significantly lower than that found in roundups of other wild animal species, he said.

10 years of capture data scoped

Scasta recently reviewed 10 years’ worth of Bureau of Land Management (BLM) data on the capture of wild mustangs and burros. The 70 captures from 2010 to 2019 involved nearly 29,000 horses and more than 2,000 burros in nine states (Arizona, California, Colorado, Idaho, Montana, Nevada, Oregon, Utah, and Wyoming). There were 36 helicopter gathers and 34 bait-trapping gathers. During helicopter gathers, horses are driven by a helicopter that flies behind and slightly above the herd until the horses reach an enclosure. In bait-trapping, the horses freely enter a wide enclosure that contains water or food, without human presence. A hidden ground crew closes the gate with remote control.

Across the decade of data, 96 horses and four burros died or were euthanized during or just after the bait-trap gathers, and 268 horses died during or just after the helicopter gathers, said Scasta. (Based on the information available, the BLM does not routinely carry out helicopter gathers on burros, he added.) This yields a mortality rate of 1.7% for bait-trap gathers and 1.0% for helicopter