Winter ecology and habitat use of lesser prairie-chickens in west Texas, 2008-11

Abstract

The lesser prairie-chicken (Tympanuchus pallidicinctus) has experienced declines in population and occupied range by more than 90 percent since the late 1800s. The lesser prairie-chicken has been listed as a candidate species for protection under the Endangered Species Act and is undergoing review for actual listing. Populations and distribution of lesser prairie-chickens in Texas are thought to be at or near all time lows. These factors have led to substantially increased concern for conservation of the species. It is apparent that sound management and conservation strategies for lesser prairie-chickens are necessary to ensure the long-term persistence of the species. To develop those strategies, basic ecological information is required. Currently, there is a paucity of data on the wintering ecology of the species. We examined home range, habitat use, and survival of lesser prairie-chickens during the winters of 2008–9, 2009–10, and 2010–11 in sand shinnery oak (Quercus havardii) landscapes in west Texas. We captured and radio-tagged 53 adult lesser prairie-chickens. We obtained sufficient locations to estimate winter home-range size for 23 individuals. Home-range size did not differ between years or by sex. Although female prairie-chickens had slightly larger home ranges (503.5 ± 34.9 ha) compared to males (489.1 ± 34.9 ha), the differences were not significant ( t 2 = 0.05, P = 0.96). During the nonbreeding season, we found that 97.2 percent of locations of male and female prairie-chickens alike were within 3.2 kilometers (km) of the lek of capture. Most locations (96.8%) were within 1.7 km of a known lek and almost all locations (99.9%) were within 3.2 km of an available water source. Habitat cover types were not used proportional to occurrence within the home ranges, grassland dominated areas with sand shinnery oak were used more than available, and sand sagebrush (Artemisia filifolia) areas dominated with grassland as well as sand sagebrush areas dominated with bare ground were both used less than available. Survival rates during the first 2 years (year 1: 0.846 ± 0.141; year 2: 0.827 ± 0.092) were among the highest ever reported for the species during the nonbreeding season. Survival was markedly decreased in year 3 (0.572 ± 0.136) and resulted in an overall nonbreeding season average of 0.721 (± 0.0763). These are still among the highest survival rates reported for the species; it does not appear that winter season mortality is a strong limiting factor in lesser prairie-chicken persistence in the study area.