Helicopter‐Based Chemical Immobilization of Mountain Goats in Coastal Alaska

Abstract

The development, evaluation, and refinement of effective and humane capture methods for wildlife studies is important for increasing our capacity to understand and effectively manageand conserve wildlife populations. Carfentanil has been the primary agent used to chemically immobilize mountain goats (Oreamnos americanus) during the past 40 years. However, carfentanil is no longer commercially available for wildlife captures in North America. To investigate viable alternatives for mountain goat capture, we conducted field trials using thiafentanil to immobilize free‐ranging mountain goats via aerial darting methods; thiafentanil responses were then compared to a standard and widely used carfentanil dose. During June–October, 2005–2020, we immobilized mountain goats with either 2.4–3.0 mg carfentanil (n = 444) or 6.0–7.0 mg thiafentanil (n = 68) across a range of different field conditions at 6 different study sites in coastal Alaska. Induction and recovery times were more rapid (and subsequent immobilization times reduced) using thiafentanil compared to carfentanil. In most other respects, however, immobilization characteristics (i.e., body temperature, pulse rate, relative oxygen saturation) were virtually indistinguishable between individuals immobilized with carfentanil or thiafentanil. During typical immobilizations, mean rectal temperature increased 1.8° C, but increased as much as 3.0° C in some extreme cases. Administration of supplemental oxygen resulted in substantial, potentially clinically significant increases in peripheral capillary oxygen saturation, arterial oxygen, and pH in immobilized mountain goats. Our findings indicate that thiafentanil is an effective alternative to carfentanil for chemical immobilization of mountain goats and may offer some important advantages, particularly when immobilizing mountain goats and other species in difficult and potentially dangerous capture environments. © 2021 The Wildlife Society.

Snow avalanches are a primary climate-linked driver of mountain ungulate populations

“…Adult male and female mountain goats were captured using standard helicopter darting techniques 68 . During handling all animals were fitted with mortality-sensing VHF and/or GPS radio-collars (Telonics Inc., Mesa, AZ).…”

“…Mountain goats in this region are widespread and occur at low to moderate densities, typical of northern coastal areas inhabited by the species 55,60 . Populations exhibit a high degree of local-scale population genetic differentiation, with limited movement among geographically discrete mountain complexes 28,61,62 .…”

Unravelling the complex biogeographic and anthropogenic history of Alaska’s mountain goats

“…For hunter harvest samples, tissue was collected by Alaska Department of Fish and Game (ADFG) biologists during inspections of hunter harvested animals. In addition, tissue samples were collected from immobilized animals during capture and handling events associated with field research activities (White, Watts, et al, 2021; U.S. Fish & Wildlife Service and ADFG Institutional Animal Care and Use Committees protocols: 2017-006, 05-11, 2016-25, 0078-2018-68, 0039-2017-39).…”

Quantifying the effects of recent glacial history and future climate change on a unique population of mountain goats

“…Once a pellet group was determined to be fresh using protocols from Poole et al (2011), we swabbed the outside of multiple pellets from the same pellet group and stored the swabs in a vial of Longmire's solution, a lysis buffer designed to preserve DNA and prevent contamination (100mM Tris, 100mM EDTA, 10mM NaCl, 0.5% SDS, 0.2% sodium azide). Samples were stored at -20 degrees C. Tissue samples adjacent to GBNPP were collected by Alaska Department of Fish & Game (ADFG) through harvest and research sampling following field sampling methods described in Shafer et al (2011) and White et al (2021aWhite et al ( , 2021b.…”