Re-Occupancy of Breeding Territories by Ferruginous Hawks in Wyoming: Relationships to Environmental and Anthropogenic Factors
Fig 2
Relationships of covariates with detection and re-occupancy probabilities of ferruginous hawk territories in Wyoming, USA.
Plots depict probabilities of detection (p) and re-occupancy (ψ) as functions of individual covariates from best-approximating single-season models with other covariates fixed at mean values during (A) 2011, (B) 2012, and (C) 2013. Numerical covariate relationships are illustrated as functions (black lines) with 95% CI (dotted lines), and categorical covariates as group means (bars) with 95% CI (error bars). Model selection results are presented in Table 1. Covariates are defined as follows. Subscripts indicate spatial extent of 500-m radius around central nest site; covariates without subscripts refer to the extent of putative territory (1.5-km radius), except height, which refers to the most recently used substrate. Covariates are defined as follows: height, height (m) of nest substrate; squirrel, abundance of ground squirrels (Urocitellus spp.); sage, cover (%) of sagebrush (Artemisia spp.); gas_road500, length (km) of roads associated with oil and gas fields; other_road, length (km) of other improved roads; ANS, categorical covariate representing artificial nest structures compared to all other substrates.