Nest Success of Black-Winged StiltHimantopus himantopusand Kentish PloverCharadrius alexandrinusin Rice Fields, Southwest Spain

Abstract

We monitored nests of Kentish Plover Charadrius alexandrinus and Black-winged Stilt Himantopus himantopus breeding in rice fields near the Doñana National Park (southwest Spain) during the breeding seasons 2005–2007. We used a logistic-exposure method to calculate nest success and examined daily nest survival as a function of year, locality, nest age, and date. Nest success was also calculated using a model assuming constant nest survival through time (equivalent to the Mayfield method). Daily nest survival increased during incubation in Black-winged Stilt, probably due to a higher predation risk during the first days of incubation. Daily nest survival in Kentish Plover showed little variation in relation to nest age, suggesting a constant but lower predation rate. Nest survival also varied with date in Kentish Plover and showed higher values in the middle of the nesting season. The nest success of Black-winged Stilt and Kentish Plover breeding in rice fields (50% and 45%, respectively, based on the Mayfield method) was within the range of nest success reported in stable populations breeding in natural habitats. The observations suggest that rice fields adjacent to the marshes of the Doñana National Park are an important additional breeding habitat for the two wader species studied.