Reproductive success of long-billed curlews (Numenius americanus) in northeastern Nevada hay fields

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Because of the continuing loss of native grasslands, many shorebirds that breed in the temperate zone have become increasingly dependent on nonnative grasslands associated with farming for breeding habitat. But invasive land management in nonnative grasslands has placed ground-nesting shorebirds at considerable risk. The authors 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.

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ELECTRONIC FILE - Zoology: Birds

SWAP (2/19/2016) citation:
Hartman CA, Oring LW. 2009. Reproductive success of long-billed curlews (Numenius americanus) in northeastern Nevada hay fields. [accessed 2015 Jun 1]; Auk. 126(2):420–430. http://www.bioone.org/doi/abs/10.1525/auk.2009.08062