2026-05-26 ミシガン大学
As drought intensified in Utah and Nevada, the area of suitable habitat decreased for cougar, black bear and mule deer. Image credit: M. Leclerc et al. Comm. Earth and Environ. 2026 (DOI: 10.1038/s43247-026-03530-y)
＜関連情報＞
- https://news.umich.edu/the-southwests-drought-is-shrinking-wildlifes-suitable-habitat/
- https://www.nature.com/articles/s43247-026-03530-y
アメリカ西部では、極端な干ばつによって生息に適した場所が縮小し、大型哺乳類の生存能力が低下する Extreme droughts shrink suitable habitats and reduce fitness for large mammals in the American West
Martin Leclerc,Kirby L. Mills,Mark A. Ditmer,David C. Stoner,Joseph O. Sexton,Panshi Wang,Kent R. Hersey,Cody A. Schroeder,Alyson M. Andreasen,David Choate,Derek B. Hall,Kathleen M. Longshore,Darren DeBloois,Kristin Engebretsen,Julie K. Young,Patrick J. Jackson,Kathryn A. Schoenecker & Neil H. Carter
Communications Earth & Environment Published:25 May 2026
DOI:https://doi.org/10.1038/s43247-026-03530-y
Abstract
Droughts are intensifying across the biosphere, yet the consequences of this phenomenon for wildlife habitat suitability and fitness are poorly studied. We analyzed 12 years of GPS telemetry data for three large mammal species—herbivorous mule deer (N = 2854), omnivorous black bears (N = 103), and carnivorous cougars (N = 105)—to evaluate the effects of drought on each species’ habitat selection across a 500,000-km2 aridity gradient in the interior West, USA. Additionally, we evaluated interannual variation in mule deer reproduction as a function of drought intensity. Severe drought reduced the area of highly selected habitat by 10.0% for mule deer, 14.3% for black bears, and 18.2% for cougars, suggesting stronger negative effects of drought at upper trophic levels. We also found that mule deer fawn recruitment decreased by >34% under extreme drought conditions. Our findings highlight the critical influence of drought on habitat selection of large mammals and common indices of mule deer fitness. Furthermore, we underscore the need for integrating predictions of climate-driven environmental changes into wildlife conservation planning.
