Factors affecting sharp-tailed grouse brood habitat selection and survival

Abstract

Sharp-tailed grouse occur across much of the northern Great Plains of North America where large grassland tracts remain. Though extirpated from areas within the Great Plains, primarily due to habitat loss, sharp-tailed grouse populations have remained relatively stable since European Settlement. Because of their need for large contiguous grasslands, sharp-tailed grouse typically occur in areas managed for or with cattle. In an effort to better understand how land management affects sharp-tailed grouse, we studied hen sharp-tailed grouse during the brooding season to identify habitat use and factors that influenced the daily survival rate of broods. We conducted our study on the Grand River National Grassland in South Dakota where cattle herbivory is the primary form of disturbance. We monitored 42 broods from 2013 to 2015. Using conditional logistic regression, we found brood-rearing hens used areas based on the distance to the nearest drainage and choose sites with less litter cover and bare ground relative to random sites at a microhabitat scale. Variables associated with variation in survival did not align with those shown to influence habitat selection. We found that brood survival decreased as the relative slope of a site increased and that survival increased as the distance a hen kept her chicks from a fence line also increased. At the microhabitat scale, survival was positively related to visual obstruction and vegetation height. Our findings demonstrate the importance of numerous variables across multiple scales to brood-rearing sharp-tailed grouse. Managers of grouse populations should manage for heterogeneity, as many factors appear to shape sharp-tailed grouse brood ecology in the Great Plains.