Advances in Ecology

Research Article

Resource Selection by an Endangered Ungulate: A Test of Predator-Induced Range Abandonment

Table 2

Model-averaged parameter estimates, 95% confidence intervals (CI), and Akaike importance weights (AIW) for predictor variables included in best-fitting model of RSF for female and male Sierra Nevada bighorn sheep, Sierra Nevada, California, USA, 2002–2007. Asterisks adjacent to parameter estimates indicate 95% CIs do not overlap zero.


Variable	Female				Male
Variable	Estimate	Lower CI	Upper CI	AIW	Estimate	Lower CI	Upper CI	AIW

CVX15	0.18	−3.4 × 10⁻²	0.40	0.76	—	—	—	—
CVX100	—	—	—	—	−1.1 × 10⁻²	−3.4 × 10⁻²	1.3 × 10⁻²	0.08
CVX150	−3.0 × 10⁻²	−8.5 × 10⁻²	2.5 × 10⁻²	0.29	—	—	—	—
LNRISK		9.4 × 10⁻³	1.4 × 10⁻²	1.00		2.0 × 10⁻²	2.7 × 10⁻²	1.00
NDSI	−1.03^*	−1.39	−0.67	1.00	—	—	—	—
PRR	0.17^*	0.15	0.18	1.00	0.18^*	0.15	0.21	1.00
ROCK	−0.12	−0.33	9.4 × 10⁻²	0.35	−0.35	−0.80	0.11	0.63
RUG20	—	—	—	—	8.4 × 10⁻²	−7.3 × 10⁻³	2.4 × 10⁻²	0.27
RUG30	−1.3 × 10⁻³	−4.4 × 10⁻³	1.8 × 10⁻³	0.09	—	—	—	—
RUG100	—	—	—	—		3.1 × 10⁻²	9.2 × 10⁻²	1.00
RUG150		7.6 × 10⁻²	0.11	1.00	—	—	—	—
SLOPE		2.1 × 10⁻²	3.2 × 10⁻²	1.00		2.6 × 10⁻²	4.2 × 10⁻²	1.00
TRESH	—	—	—	—	−0.64^*	−0.94	−0.33	0.97

Note. Variables in RSF models for winter habitat selection by bighorn sheep included convexity over radii of 15 m (CVX15), 100 m (CVX100), and 150 m (CVX150); risk surface from locations of active mountain lions (LNRISK); normalized difference snow index (NDSI); potential relative radiation (PRR); rock cover (ROCK); terrain ruggedness over radii of 20 m (RUG20), 30 m (RUG30), 100 m (RUG100), and 150 m (RUG150); slope (degrees; SLOPE); and tree-shrub cover (TRESH).