Reproductive success of Providence Petrel Pterodroma solandri on Lord Howe Island.

The only significant breeding locality of the Providence Petrel Pterodroma solandri is Lord Howe Island, Australia, where the populationis considered Vulnerable. During the 2000 and 2001 breeding seasons, data were collected on hatching, fledging and breeding success, andon egg and chick mortality. Annual breeding success was 34%'36% in burrows that were visited repeatedly and among adults and chicks handled at least once, and 54% in burrows that were visited only twice and contents not handled. The breeding success of individual adults was positively correlated with body condition, the relationship being stronger for males than for females. Egg losses occurred throughout the incubation period, but chick losses were concentrated within the first four weeks from hatching. Egg and chick mortality were strongly correlated with the distance of the nest from the burrow entrance, with more losses occurring in nests close to the entrance. The main causes of breeding failure were inundation of burrows and predation of eggs and chicks by the endemic Lord Howe Woodhen Gallirallus sylvestris.Although breeding success was less than that of some other procellariiforms, we were unable to identify any new conservation measures to enhance reproductive output.