Reproductive Success of Long-billed Curlews (Numenius americanus) in Northeastern Nevada Hay Fields

Abstract

ABSTRACT. Because of the continuing loss of native grasslands, many shorebirds that breed in the temperate zone have become increasingly dependent on non-native grasslands associated with farming for breeding habitat. But invasive land-management in non-native grasslands has placed ground-nesting shorebirds at considerable risk. We studied the reproductive success of Long-billed Curlews (Numenius americanus) breeding in northeastern Nevada, in a landscape dominated by hay fields, between 2003 and 2006. Observed nest density was as high as 9 nests per 100 ha, and mean nest success was 31%, with considerable interannual variation. Predation, predominantly by large mammalian predators such as Coyotes (Canis latrans), was the greatest cause of nest failure in Long-billed Curlews. Flooding of nests during irrigation of hay fields and trampling and disturbance by cattle also affected nest success, albeit to a lesser degree. Fledging success of radiomarked chicks averaged 47%, and hay fields were the preferred b...