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.

Combining historic observations of mountain goats and bighorn sheep obtained from regional biologists to see what we can learn from data we already have.


Witness the expansion of mountain goats as captured by observations in the database:

Bighorn sheep and mountain goat locations captured in the database from 1937- 2011

Blue = Bighorn sheep
Red= Mountain goat 

Integrated Databases

Building Databases for Bighorn Sheep and Mountain Goats in the GYA​​

The goals of the database effort are numerous and include the development of a series of compatible databases for storing point, polygon and demography data for bighorn sheep and mountain goats. The 3 main objectives for creating an aggregate point database were to: 1) consolidate all bighorn sheep and mountain goat observations in the GYA, 2) document the expansion of mountain goat range from initial release sites, and 3) model habitat suitability. The 3 main objectives for creating a seasonal herd polygon database were to: 1) document expert knowledge of area biologists, 2) examine seasonal herd ranges in GYA, and 3) compare point and polygon data. The main objective for creating a demography database is to describe and evaluate population trends and recruitment rates (as index by young-adult ratios) of bighorn sheep and mountain goat herds in the GYA.

We captured data provided by Yellowstone National Park, Grand Teton National Park, Montana Fish Wildlife & Parks, Wyoming Game & Fish, Idaho Fish & Game, Montana State University and Wild Things Unlimited. Data was also gleaned from Master of Science theses from Colorado State University, Montana State University and University of Montana. We successfully captured a diverse assortment of data types such as aerial and ground locations, GPS and radio-collar data, harvest data, and even observations made opportunistically by hunters and park visitors.

Between 15 January 2010 and 31 December 2011, we captured 27,826 observations of bighorn sheep and mountain goats in the Greater Yellowstone Area Mountain Ungulate Project point database. During this time we captured 21,838 bighorn sheep and 5988 mountain goat point locations. The earliest bighorn sheep observation in the database was made on September 15, 1937 in Grand Teton National Park and the most recent observations were made by Montana State University on September 17, 2011 in Montana. The earliest mountain goat observation was made on June 15, 1947 near the South Fork of Rock Creek in the Beartooth Mountains of Montana and the most recent observations were made by Montana State University in Montana on September 20, 2011.

​Our aggregation of point and polygon data for bighorn sheep and mountain goats in the GYA is unique in breadth, depth, and scope. The multi-species nature of the research initiative allows for a broader ecological understanding of mountain ungulates than single-species efforts. The inclusion of records both past and present provides a deeper understanding of mountain ungulate ecology than short-term studies. The distribution of data we've collected throughout the GYA gives us a much wider ecosystem perspective than smaller-scale studies. 

written by Mike Sawaya

Mountain Ungulate Project

Greater Yellowstone Area 

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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.

Bighorn sheep and mountain goat herd polygons in the northern GYA captured in the polygon database

Bighorn sheep
Light blue = lambing areas
Medium blue = summer range
Dark blue = winter range
Mountain goat
Medium red = summer range
Dark red = winter range

Seasonal bighorn sheep locations captured in the point database.

Seasonal bighorn sheep locations captured in the point database.