Breeding biology of Brown Noddies Anous stolidus at their southern-most breeding site, Gough Island, in comparison to other sites

Abstract

We investigated the breeding biology of the Brown Noddy Anous stolidus at its southern-most breeding locality, cold-temperate Gough Island (40°S) In the South Atlantic Ocean. We monitored 19 nests over three seasons for breeding schedules, and measured the growth of eight chicks and six fledglings during the 2005/06 breeding season. Across all seasons, egg-laying occurred between 2-12 December, mean incubation was 37 days and median hatch date was 15 January. Three late hatch dates suggest that replacement clutches can be laid If failure occurs early in the season. Chicks fledged after a mean of 46 days, but remained In the vicinity of the nest and were provisioned by adults for up to 11 days. Hatching success was 88%, fledging success 92% and breeding success 81%, which is higher than at most other sites. The size, chick growthrates and pre-fledging fast displayed by Gough's Brown Noddies are similar to that of Brown Noddies breeding at other mid-latitude Atlantic locations. These similarities of these migratory noddy populations, as well as mirrored breeding schedules suggest a single mid-latitude Atlantic meta-population.