NZ Black-browed Mollymawk

Forest and Bird, Volume 21, Issue 4, 1 November 1990, Page 28

NZ Black-browed Mollymawk

The NZ black-browed mollymawk nests only on Campbell Island, our most southern subantarctic island. A survey in 1987-88 revealed 19-26,000 pairs, which points to a total population of about 90,000. Immatures of this species often disperse northwards and are common in temperate waters around mainland New Zealand. Large numbers of immatures and some adults drown on longlines in our waters but exact figures are not known. Marked birds from Campbell Island have been recovered drowned on longlines off southern Australia.

A 38-57 percent decline in numbers on Campbell Island has occurred since the 1940s with the worst affected colonies falling by 88 percent. Temperature changes affecting food supplies have been implicated in causing declines in marine species, such as sea elephants and rockhopper penguins at Campbell Island, but fisheries by-catch may well be affecting mollymawk numbers. The decline in the South Indian Ocean Kerguelen Island population of black-browed mollymawks has been attributed to trawler mortality.