Figure 1. Map of the GYA depicting the current number of instrumented bighorn sheep and mountain goats within our study regions, 2009 - 2015.
Mountain ungulates, while regarded as iconic and charismatic wildlife species, are the least studied and understood large mammals in the Greater Yellowstone Area (GYA). Bighorn sheep (Ovis canadensis) are native to the GYA but have struggled to rebound to historic numbers since the early 1900’s. In contrast, mountain goats (Oreamnos americanus) are considered non-native in the GYA according to historical records and have been steadily expanding their range since their initial introduction in the 1940s. The current distribution of both species represents an opportunity to study the spatial ecology of allopatric and sympatric populations in order to inform management decisions regarding potential species overlap with continued mountain goat range expansion, and also examine seasonal niche overlap. In addition, there is an opportunity to develop and implement novel tools to bolster bighorn sheep restoration regionally and throughout their range.
Our field efforts have been ongoing since 2009 and resulted in the deployment of 337 GPS collars (bighorn sheep = 275 and mountain goats = 62) throughout nearly all high elevation occupied mountain ungulate terrain within the GYA (Figure 1). These data are being used to study seasonal resource selection, niche overlap between sympatric populations, seasonal movement strategies, and testing the link between heterogeneity in seasonal movement strategies and robust herd demographics. Collectively, these topics directly relate to the management and conservation concerns surrounding bighorn sheep and mountain goats in the GYA and will provide useful tools to inform the management of these two iconic, yet under studied species.
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Combining historic observations of mountain goats and bighorn sheep obtained from regional biologists to see what we can learn from data we already have.
Ongoing telemetry studies across the GYA are being used to understand population vital rates and dynamics, spatial ecology, and competition.
What are the tractories of bighorn sheep and mountain goat populations in the GYA? We dive in to the data to find out.
Using new and rigorous methods to understand habitat selection and expansion of the non-native, invading mountain goat.
Annual and regional climate factors may impact recruitment of bighorn sheep across the GYA.
Spatial Ecology of Mountain Ungulates in the Greater Yellowstone Area