Effects of rangeland management on survival of female greater prairie‐chickens

Abstract

ABSTRACTIdentifying relationships between habitat selection and population processes is important for habitat management and wildlife conservation. For prairie‐obligate species, space use and demography in extant grasslands are influenced by habitat conditions caused by rangeland management practices associated with livestock production. Greater prairie‐chickens (Tympanuchus cupido) are an indicator species for native tallgrass prairie ecosystems, but populations have declined in the Flint Hills ecoregion of eastern Kansas, USA because of intensification of rangeland management practices, including annual prescribed fire and high stocking densities. Patch‐burn grazing is a rotational system that provides heterogeneous habitats and can improve productivity of grassland birds, but the effects of grazing systems on habitat use or survival of greater prairie‐chickens are unknown. We used 3 types of survival analyses to investigate impacts of rangeland management on female greater prairie‐chickens in the central Flint Hills during 2011–2013: Kaplan–Meier models and Cox proportional hazards to examine factors affecting annual survival rates, hazard functions to assess seasonal patterns of mortality, and Andersen–Gill models to explore the links between habitat selection and cause‐specific mortality risk. Females captured at properties managed with patch‐burn grazing had annual survival rates (0.61 ± 0.07 SE) that were 35% higher than females on properties managed with annual burning and intensive early cattle stocking (0.45 ± 0.06). Moreover, females that selected habitats associated with intensive management had increased mortality risk and were particularly vulnerable to avian predators, whereas females that selected habitats created by patch‐burn grazing experienced lower overall mortality risk but were more vulnerable to mammalian predators. Overall mortality risk was significantly reduced under patch‐burn grazing management, and widespread implementation of annual spring burning and intensive early stocking is likely depressing survival of greater prairie‐chickens in the Flint Hills ecoregion. Our results join a growing body of evidence that patch‐burn grazing can provide higher quality grassland habitats for native wildlife species than current rangeland management associated with intensive cattle production. © 2017 The Wildlife Society