Nest survival of Long-billed Curlew in Nebraska
109 – 113
1 August 11
Cory J. Gregory, Stephen J. Dinsmore, Larkin A. Powell, Joel G. Jorgensen
Stephen J. Dinsmore
Department of Natural Resource Ecology and Management, Iowa State University, 339 Science Hall II, Ames, IA 50011, USA.
Long-billed Curlew Numenius americanus is an imperiled shorebird of western North America. Populations have declined dramatically in the last 150 years from the conversion of prairie to agriculture and it is now listed as a “Tier I at-risk” species in Nebraska. We undertook a 3-year project (2008–2010) to study the nest survival of Long-billed Curlews in Nebraska. We measured vegetation characteristics at each nest site (n = 14 nests) on two different spatial scales and used program MARK to model nest survival as a function of multiple covariates. Apparent nest survival was 29% (n = 4 successful nests) and our model-based estimate of nest survival was 33% (95% CL: 24%, 93%). This estimate is similar to other estimates of curlew nest survival in Nevada (31%) and South Dakota (15% to 39%). Visual obstruction reading height (βo.vor = –4.17, 95% CL: –7.58, –0.77) and forb cover at the nest (βforb= –12.49, 95% CL: –26.14, 1.17) negatively affected survival. Bare ground cover positively affected nest survival (βbare= 3.28, 95% CL: –1.03, 7.59), but we found no evidence that nest age, grass cover, or litter depth affected nest survival. These findings suggest that Long-billed Curlews in Nebraska have a relatively low nest survival rate, but it is within the expected range for the species. Furthermore, nest survival is affected negatively by tall vegetation and forb cover at and near the nest.