A recent study on elk migration patterns in the Greater Yellowstone Ecosystem, or GYE, led by researchers at the Middleton Lab at UC Berkeley in conjunction with researchers from Wyoming, Idaho, Montana and several national organizations, provided insights into the flexibility of migration timing and its implications for the rest of the ecosystem, according to a Berkeley News article.
Elk rely on a variety of environmental and climate-based cues, such as plant “green up,” snow timing and depth, to determine when they migrate both in the fall and in the spring, according to Jon Beckmann, one of the authors of the study and science director for the Wildlife Conservation Society’s Rocky Mountain West program. Beckmann said he worked with the Idaho Department of Fish and Game to collect data on the Sand Creek herd in the western part of the GYE.
This flexibility is not seen in all species — some other animals, such as some species of birds, rely on cues like changes in day length as indications to migrate, said Gregory Rickbeil — a postdoctoral researcher from the Middleton Lab who worked on the study — in the Berkeley News article. However, as Beckmann pointed out, many ungulates, such as pronghorn and mule deer, likely have similar migratory patterns to those of elk, but elk play a particularly important role in the GYE.
“We studied elk because in terms of biomass and the numbers of migratory herds, they’re the most important migrators in the Greater Yellowstone Ecosystem,” Beckmann said.
Particularly, as climate change continues, it is likely that the environmental cues — and thus elk migration — will change, which will have a significant effect on the rest of the ecosystem, said UC Berkeley assistant professor of wildlife management and policy and senior author of the study Arthur Middleton in the Berkeley News article.
According to Jonathan Jarvis, executive director of the UC Berkeley Institute for Parks, People, and Biodiversity and the former director of the National Park Service, while changing migration patterns show that elk are already adapting to climate change, these changing migrations could have implications for predator population and ranges.
“Wolves for instance are known to travel with the elk as they move across the range,” Jarvis said in an email. “(Changes in elk migration timing) could cause the wolves to become more vulnerable to being shot/harvested outside of the park,” he added.
According to Beckmann, this study could provide insights for similar occurrences outside of the GYE, both regionally and globally.
For example, some areas of the Rocky Mountains — particularly the drier regions — are expected to experience “significant” changes to their climates in upcoming decades, which could impact the migratory patterns of elk species there, according to Beckmann.
“More globally, long-distance migration is an ecological phenomenon that is declining across the globe, and so any additional threat or stressors on long-distance migrators could be worrisome given that we’re losing a lot of long-distance migrators,” Beckmann said.