Chapter Thirteen. Habitat Selection and Brood Survival of Greater Prairie-Chickens

摘要

The Greater Prairie-Chicken (Tympanuchus cupido pinnatus) is a species that may benefit from conversion of crop ground to grassland through the Conservation Reserve Program (CRP). CRP grasslands could provide nesting and brood-rearing habitat, an important component of population persistence. Managers and policymakers currently lack evidence of CRP’s relative contribution to populations of Greater Prairie-Chicken. We used radiotelemetry to mark females (n =100) in southeast Nebraska, in a landscape which had u3e15% of land area enrolled in CRP. We examined macrohabitat and microhabitat selection of brood-rearing females (n=36) using discrete choice models, and examined the variability in brood survival using logistic exposure models. Brood-rearing females selected locations inside cool-season CRP grasslands at higher rates than rangeland, but did not select cropland. At a vegetation level, brood-rearing locations had more bare ground and forb cover than random points. However, landcover and vegetation did not affect survival rates of broods; variation in daily brood survival was best explained by temporal effects such as hatch date and brood age. Our results suggest that CRP grasslands provide acceptable broodrearing habitat, and managers should encourage land owners to create habitat with high forb content and an open understory. Broods in our study had low survival rates to 21 days (0.59; 95% CI: 0.41, 0.77), which may explain the low juvenile/ adult ratio observed in hunter-killed birds in the region. Disturbance of CRP fields to increase bare ground and forb cover may improve their value to Greater Prairie-Chicken broods.