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

The Auk

C. Alex Hartman¹  Lewis W. Oring¹ 

关键词: agriculture;    fledging success;    hay field;    Long-billed Curlew;    nest success;    Numenius americanus;    productivity;   

DOI  :  10.1525/auk.2009.08062

学科分类：动物科学

来源: Central Ornithology Publication Office

【 摘 要 】

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 brood-rearing habitat, especially in dry years. Mammalian predation was the greatest cause of chick mortality, whereas ranching activities had no noticeable effect on chick survival. In all years, Long-billed Curlews exhibited a high propensity for renesting after a first nest failure. After taking renesting into account, per-female nest success averaged 45% and mean annual productivity was 0.70 female chicks hatched and 0.33 female chicks fledged per breeding female. These results suggest that despite potential negatives associated with high land-management intensity, hay fields in northern Nevada can be of great value in conservation of the Long-billed Curlew.

【 授权许可】

Unknown