Study: Decreasing snow cover threatens wildlife
May 18, 2013
Declining snow cover puts animals and plants across the Northern Hemisphere at risk, according to a "Frontiers in Ecology and the Environment" report published earlier this month.
For the Lake Tahoe Basin, that warming trend could mean increased conflicts between bears and humans, more migrations away from the region and even some local extinctions, regional wildlife experts said.
Since 1970, snow cover in the Northern Hemisphere has shrunk by more than 1.2 million square miles during the spring and shifted from February to January, while spring melt has accelerated by almost two weeks, according to the study from the University of Wisconsin, Madison.
Less snow on the ground in March and April leaves animals such as the long- and short-tailed weasels, the pine martin and the Sierra Nevada snowshoe hair at higher risk of predation, according to Nevada Department of Wildlife Western Regional Biologist David Catalano.
"If this trend continues, having these very poor winters, we could see some local extirpations. They won't go extinct, they just won't be in the area," Catalano said.
Many small animals burrow beneath the snowpack, where temperatures are warmer and more stable. Without snow cover in the spring, those animals face increased predation and extreme weather that can put some populations at risk, Catalano said. Already NDOW scientists have recorded fewer Sierra snowshoe hare east of Tahoe, but the size and cause of the population decrease remain unclear, he said. The hares turn white in the winter, but without snow the camouflage becomes more of a detriment than an advantage
The updated Nevada Wildlife Action Plan cites climate change as a "human generated influence" tied to wildlife disease events and a whole section of the document outlines how global warming predictions can contribute to pathogen emergence, altered habitats and droughts.
"A growing body of evidence has linked changing climate with observed changes in fish and wildlife and their habitats," the action plan reads.
California Department of Fish and Wildlife Program Supervisor Jason Holley said a changing climate might result in animals migrating away from the basin in search of higher, cooler territory. Wildlife that goes into hibernation might wake up sooner as snow melts earlier, causing potential human and animal conflicts, according to Holley.
"It's too early to call it jeopardy, but it could definitely change the behavior of animals. Less snowpack could reduce the amount of time animals like bears hibernate. When they wake up, there had better be food available," he said.