Demography of Uinta Ground Squirrels Using Closed Robust Design Models
Class
Article
Department
Wildland Resources
Faculty Mentor
Lise Aubry
Presentation Type
Oral Presentation
Abstract
Throughout the 1960s and 1970s, NSF supported a long-term demographic study of the Uinta Ground Squirrel 'UGS' (Spermophilus aramatus) in Logan Canyon. Since this study, dramatic changes to local climate have been observed, and warming of this region is three times that undergone by the Earth over the past 100 years. The availability of historic and contemporary data in the same location provides the unique opportunity to assess the impact of climate change on a hibernator's demography over a 50-year period. As a first step in assessing whether or not UGS are at an increased risk of match or mismatch with the resources they consume in response to climate change, we estimated basic demographic features of the UGS population under study (n = 137) using a Closed Robust Design Capture-Mark-Recapture modeling framework. We found that i) survival was higher in 2013 than in 2014, but that estimates of survival were not comparable across years because of sampling scheme differences; ii) 2014 survival estimates were comparable to survival estimates obtained from historical data; and iii) sex and year were good predictors of changes in survival. Most likely, we did not possess the statistical power necessary to pick up an effect of age on survival. An additional year of data collection and a new modeling framework should help us alleviate the statistical issues we have faced here.
Start Date
4-9-2015 10:00 AM
Demography of Uinta Ground Squirrels Using Closed Robust Design Models
Throughout the 1960s and 1970s, NSF supported a long-term demographic study of the Uinta Ground Squirrel 'UGS' (Spermophilus aramatus) in Logan Canyon. Since this study, dramatic changes to local climate have been observed, and warming of this region is three times that undergone by the Earth over the past 100 years. The availability of historic and contemporary data in the same location provides the unique opportunity to assess the impact of climate change on a hibernator's demography over a 50-year period. As a first step in assessing whether or not UGS are at an increased risk of match or mismatch with the resources they consume in response to climate change, we estimated basic demographic features of the UGS population under study (n = 137) using a Closed Robust Design Capture-Mark-Recapture modeling framework. We found that i) survival was higher in 2013 than in 2014, but that estimates of survival were not comparable across years because of sampling scheme differences; ii) 2014 survival estimates were comparable to survival estimates obtained from historical data; and iii) sex and year were good predictors of changes in survival. Most likely, we did not possess the statistical power necessary to pick up an effect of age on survival. An additional year of data collection and a new modeling framework should help us alleviate the statistical issues we have faced here.