HOW DO ENVIRONMENTAL CUES INFLUENCE DAILY MOVEMENT OF PRONGHORN IN SOUTHEAST OREGON?

Jerrod L Merrell; University of Nevada, Reno; jmerrell@unr.edu; Dr. Kelley M. Stewart, Dr. Don G. Wittaker

Movement between distinct locations is an important strategy used by animals to escape environmental extremes or to maximize access to forage. This behavior occurs in multiple taxa around the world. Animal movements can fall into many classifications such as long-distance migration, exploratory movements, short-distance migrations, range shifts, and daily movement within a home range. Being able to distinguish movement types is important for conservation of habitat and movement corridors. It is also important to examine environmental factors that influence the initiation of these movements. Pronghorn (Antilocapra americana) make daily decisions about distances to move to best access high quality forage and minimize the effect of environmental changes. Pronghorn movements have been a focus of study, but little is known about how environmental cues influence these movements. Our objective was to identify daily changes in pronghorn home ranges and understand how these changes influence movement types in a population of pronghorn in southeast Oregon, USA. We deployed 203 GPS collars on adult female pronghorn between 2019 and 2021 by helicopter capture. We recorded daily precipitation, temperature and wind speed within a home range and used multiple regression to understand the influence on daily movements. We used time series, by month and seasonal, to look at how movements vary at separate times of the year. We identified individual variation of the effect of environmental cues and distances moved. We also identified variation of the influence of environmental cues during different seasons. Our observations indicate that pronghorn movement is influenced by daily variation of environmental factors such as precipitation, temperature, and wind speed. And that these variations are influenced by seasonality of weather.

Restoring/Monitoring Wildlife Populations and Habitats 1