Final Report: Predicting Future Forage Conditions for Elk and Mule Deer in Montana and Wyoming
Dates
Publication Date
2022-04-22
Acquisition Date
2021-04-01 11:46:00
Citation
Tabitha A Graves, 2022-04-22, Final Report for Predicting Future Forage Conditions for Elk and Mule Deer in Montana and Wyoming: .
Summary
Ungulate populations across the West have adapted to specific patterns in forage quantity, quality, and timing that ultimately influence the number of animals. We assessed potential for climate change to affect forage quality and availability for ungulates in the West. First, we evaluated multiple satellite remote sensing datasets and found that in some parts of the western U.S., growing season dates have shifted by over 30 days. We found agreement in the direction of recent trends in growing season dates across ~60% of the West. Substantial shifts in vegetation timing can have outsized effects on the wildlife that depend on matching migration timing to spring green up. For example, migrating mule deer follow the pattern of vegetation [...]
Summary
Ungulate populations across the West have adapted to specific patterns in forage quantity, quality, and timing that ultimately influence the number of animals. We assessed potential for climate change to affect forage quality and availability for ungulates in the West. First, we evaluated multiple satellite remote sensing datasets and found that in some parts of the western U.S., growing season dates have shifted by over 30 days. We found agreement in the direction of recent trends in growing season dates across ~60% of the West. Substantial shifts in vegetation timing can have outsized effects on the wildlife that depend on matching migration timing to spring green up. For example, migrating mule deer follow the pattern of vegetation as it greens up in the spring when it is most nutritious. We assessed how green-up will change and how changes may affect mule deer migration in Wyoming. We projected that green-up of vegetation will generally occur earlier, particularly in drier years. We found future green-up along deer migration paths will be shuffled and of shorter duration, potentially decreasing the availability of high quality forage. This reduction in the benefit of migration could reduce the number of migrating deer. If local forage resources limit resident population size, mule deer abundance could decline. We provide baseline information on recent changes in the timing of forage, a framework to assess climate effects on forage, information on the quality of remote sensing data sources used for this research, improved understanding of the connections between climate and vegetation timing, and maps of projected future green-up. These products will be useful for biologists as they plan habitat treatments, consider effects of energy developments, and manage big game populations.
