Energetic development holds deer back during spring migration: study

NNA |
Updated: October 10, 2022 01:16 STI

Washington [US]Oct. 10 (ANI): A new study shows how development disrupts the movements of deer, causing the animals to lose their ability to match their diet with the surge of the most nutritious spring plants.
That is, indeed, the new finding from a collaborative study by the US Geological Survey (USGS) and the University of Wyoming, which quantified how mule deer run out of forage when energy development disrupts their habitat corridors. migration.
“Mule deer are known for the accuracy with which they match their movements with spring greening, so this result was particularly striking,” says lead author Ellen Aikens, who holds a UW Ph.D. is now a graduate of the USGS South Dakota Cooperative Fish and Wildlife Research Unit. “The gas wells made them let out the best food of the year.”
The article “Industrial energy development decouples ungulate migration from the green wave” appears today (Thursday) in the leading scientific journal Nature Ecology & Evolution.
Every spring in the American West, mule deer migrate to follow the greening of plants growing at different elevations. Biologists call it “surfing the green wave”. Mule deer rely on this surfing behavior to find the youngest, most nutritious plants that allow them to recover from winter and grow bigger for the next lean season.
However, the new study shows how development disrupts deer movements, causing deer to lose their ability to match their diet with the surge of the most nutritious spring plants.
The 14-year-old study tracked a herd of migrating mule deer that winters in sagebrush pools and summers in the Sierra Madre mountains, about 15 miles southwest of Rawlins.
During the study period, dozens of new wells were drilled for coal bed methane extraction in the middle of an existing mule deer corridor. Long-term movement data allowed a before-after comparison of the effects of development expansion on mule deer movements.
Previous research by the team detailed how mule deer behaviors changed in response to new gas wells, causing them to take detours, speed through well pads and stop less to Eat.
For the new study, the team analyzed deer movements – alongside daily changes in spring greenness estimated from remote satellite images – to measure how deer surfed along the corridor, both upstream and downstream. downstream of energy development, and over the 14-year period.

“The deer movements in response to the gas field were unmistakable,” Aikens said.
As the intensity of development increased over time, the deer began to “hold on” when they reached the natural gas wells. They interrupted their spring migration and let the wave of green vegetation pass, decoupling from their best food resources at a crucial time of the year.
Overall, the sinks resulted in a 38.65% reduction in green wave surfing over time.
There is no evidence that mule deer have acclimatized to development and the associated increase in human presence, truck traffic, and noise. Small and large scale developments have altered the surfing behavior of green waves to a similar degree.
The study will help wildlife managers understand how corridors need to be intact to maintain their ecological functionality. In this case, the deer could still move through the gas field, but a key function of the migration corridor – following the green wave along the course at the ideal stage of plant growth – was lost.
The finding is important because if migrating ungulates cannot maximize foraging, it will reduce the overall benefit of migration, which is often the most cost-effective strategy for ungulates as diverse as mule deer in Wyoming, the caribou in the Arctic or the antelope chasing the rains across the African plains. The study is a cautionary tale, providing a clear mechanism for how development in corridors can reduce the benefits of migratory behavior, ultimately leading to migration loss and population decline on heavily impacted landscapes.
Researchers hope the findings can help pave the way for maintaining mule deer migrations.
“The impact is pretty clear, but also points to conservation solutions that will allow us to maintain viable migrations for generations to come,” says co-author Matt Kauffman, of the USGS Wyoming Cooperative Fish and Wildlife Research Unit at the UW. “Once migrations have been mapped, development can be planned to minimize disruption from migrating herds, whether in Wyoming, the American West, or anywhere else landscapes are rapidly changing.”
Other co-authors on the paper include Teal Wyckoff of The Nature Conservancy and Hall Sawyer of Western EcoSystems Technology Inc.
The work comes at a good time, as numerous state and federal initiatives have been implemented over the past five years in the United States to map migration corridors and reduce their impacts. In Wyoming, state wildlife managers have long sought to map and conserve migration corridors, now guided by state policy. Globally, efforts are underway to map the world’s ungulate migrations for use in conservation and development planning.
“This new research provides the most compelling case, to date, that efforts to minimize development in migration corridors will benefit their long-term persistence in changing landscapes,” Kauffman said. (ANI)