Space Use of Female Greater Prairie-Chickens in Response to Fire and Grazing Interactions

Abstract

Ecological interactions between fire and grazing have shaped the evolutionary history of grassland ecosystems. Currently, grassland birds have experienced ongoing population declines, following widespread implementation of intensive rangeland management practices that reduce habitat heterogeneity. Patch-burn grazing is an alternative rangeland management strategy that promotes habitat heterogeneity and biodiversity. We conducted a 3-yr. field study in the central Flint Hills of Kansas to compare the spatial ecology of female Greater Prairie-Chickens (Tympanuchus cupido) in rangelands managed with intensive rangeland management versus patch-burn grazing. This is the first study on the effects of patch-burn grazing on the space use decisions of Greater Prairie-Chickens at the home range scale. We used seasonal estimates of home range for 6-mo breeding and nonbreeding periods, as well as resource utilization functions to investigate the response of female prairie chickens to landscape metrics describing fire, grazing, and proximity to anthropogenic structures or lek sites. In our analysis of all radio-marked females, distance to lek was consistently the strongest predictor of space use during both breeding and nonbreeding seasons. Females captured at properties managed with patch-burn grazing selected areas with low stocking rates and high fire frequencies, and they avoided recently burned areas. Our study provides new evidence that patch-burn grazing can improve grassland habitat for Greater Prairie-Chickens, an umbrella species in the tallgrass prairie ecosystem. Patch-burn grazing created preferred habitats for female Greater Prairie-Chickens, with a relatively frequent fire return interval, a mosaic of burned and unburned patches, and a reduced stocking rate in unburned areas avoided by grazers. Widespread implementation of patch-burn grazing could result in significant improvements in habitat quality for wildlife in the tallgrass prairie ecosystem.