Using individual‐based habitat selection analyses to understand the nuances of habitat use in an anthropogenic landscape: a case study using greater sage‐grouse trying to raise young in an oil and gas field

Abstract

Habitat selection analyses conducted at an individual level may reveal patterns in selection not apparent when individuals are pooled in population‐level approaches. Using GPS transmitters that gather high‐resolution location data, we explored fine‐scale habitat selection and space use within home ranges of female greater sage‐grouse Centrocercus urophasianus that raised young (brood‐rearing sage‐grouse) in an oil and gas development area. To evaluate fine‐scale habitat selection of brood‐rearing sage‐grouse we used a two‐stage approach. First, we developed models for each individual (i.e. individual‐level modeling) and evaluated individual‐level responses to modified habitats and infrastructure. Second, we averaged individual‐level estimates using a bootstrap approach to make population‐level inference. The average home range size during brood‐rearing in our study, from nest hatch to six weeks, was 0.85 ± 0.21 km2. Individual and population‐level results indicated that brood‐rearing females consistently selected for natural vegetation and avoided disturbed surfaces at a fine spatial scale. Our study area included substantial areas of recent (≤ 10 years) habitat reclamation which females also avoided. Visible power lines consistently led to avoidance behavior. In addition to consistent patterns of habitat selection, our individual models demonstrated variability and contrasting behaviors in how brood‐rearing females responded to specific infrastructure features and anthropogenic water bodies. At the population‐level anthropogenic water bodies were avoided but at the individual‐level the intensity of avoidance was variable among individuals. Individual variability was often explained by the age of the brood‐rearing female (first year or adult). First year females were more likely than adults to use habitats close to infrastructure and consistently established home ranges in areas with more surface disturbance and infrastructure when compared to adults. Our results provide new insights into fine‐scale habitat‐selection strategies used by female sage‐grouse with broods in an area where oil and gas infrastructure is widespread and cannot be avoided.