The Black-winged Petrel on Mangere Island, Chatham Islands
|Title||The Black-winged Petrel on Mangere Island, Chatham Islands|
|Publication Type||Journal Article|
|Year of Publication||1991|
|Type of Article||paper|
The first known breeding of the Black-winged Petrel (Pterodroma nigripennis) on Mangere Island was studied in 1987-88 from the pre-laying period to part way through the chick rearing period. The first returning bird was noted on 30 November; eight incubated eggs were found, calculated to have been laid in mid-January. The eggs hatched in late February - early March; fledglings were calculated to have left in late May. The breeding cycle was about 2 weeks later than at more northerly breeding sites. The approximate mean incubation shift was 13.5 days. The colours of chicks are described in detail. Only two of the five chicks that hatched were still alive by the end of the study. Interference at the nest site by other petrel species apparently caused some nesting failures. No birds were found undergoing active wing or tail moult. The brood patches of most adults examined were largely bare in late January and February and were refeathering in March. The birds were active only at night.