Breeding systems of New Zealand Snipe Coenocorypha aucklandica and Chatham Island Snipe C. pusilla; are they food limited?

• Published in: Ibis
• Main Author: MISKELLY, COLIN NI.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1990
• Subjects: New Zealand; Snares Islands
• Online Access: http://dx.doi.org/10.1111/j.1474-919x.1990.tb01056.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1474-919X.1990.tb01056.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1474-919X.1990.tb01056.x

New Zealand Snipe Coenocorypha aucklandica w ere studied over six breeding seasons on the Snares Islands. The study area (7.5 ha) held about 20 pairs at a density of 3.2 ± O.5 pairs/ha, plus 5 to 25 nonterritorial birds. Most matings were monogamous but simultaneous polygyny was recorded in one territory (by two different males) in four consecutive seasons. Males courtship fed females before egg‐laying. The typical clutch was two eggs, laid three days apart. Incubation was shared equally by the sexes in monogamous pairs and took 22 days. Some females with polygynous mates attempted to incubate unaided, which took about 38 days. Broods were split at hatching, with the male caring for the first chick to leave the nest. Chicks were fed by adults for at least 41 days, and did not become independent until about 65 days old. Growth rates were slow compared to Common Snipe Gallinago gallinago and full plumage took about 54 days to attain. No pairs were double‐brooded but 43% of pairs that failed during incubation or early chick‐rearing renested together. Some breeders of both sexes who had lost their dependent chick bred a second time with a new mate while their first mate continued rearing the surviving chick (sequential polygyny and polyandry). Hatching success was 80%, and fledging success was 48%. Each pair produced, on average, O.6 fledglings per year. Chatham Island Snipe C. pusilla were studied on Rangatira Island during the 1983–84 breeding season. Breeding density was about 5.6 pairs/ha. The breeding system was very similar to that for C. aucklandica but chicks became independent at about 41 days old. Hatching success was 89%. Compared to Common Snipe, Coenocorypha snipes occurred at high densities, had courtship feeding, large eggs, a long interegy interval, a small clutch, shared incubation and a long incubation period. Nest desertion rates were high, but overall hatching success was also high, chick growth rates were slow, there was a long period of chick dependence and a long relaying interval following ...