The broad-billed prion is the most distinctive member of the otherwise confusingly similar prion group of seabirds. With its bizarrely wide bill and high forehead, the broad-billed prion has an almost cartoon-like character when seen at close range. The broad bill is part of a suite of adaptations for feeding on minute marine organisms. Analogous with baleen whales, broad-billed prions have a fringe of comb-like filters around the upper mandible, a distensible pouch between the bowed lower mandibles, and a muscular tongue to force water out through the filters. These same features are present but not as far developed in the related Salvin’s and Antarctic prions. All six prion species look very similar at sea, being slightly smaller than a red-billed gull, blue-grey and black above, and white below. Broad-billed prions breed around southern New Zealand and in large numbers on the Chatham Islands. The southern populations were decimated by a winter storm in 2011, when an estimated quarter of a million birds were blown ashore and died, mainly on west coast beaches of the North Island.
Broad-billed Prion |
Government evidence of impact of climate change:
IUCN Red List Assessment, Pachyptila vittata
A severe storm in 2010 caused considerable mortality on breeding islands around Stewart Island (Miskelly 2013); and predicted increases in the frequency and ferocity of such storms may impact part of the population sufficiently to impact the global abundance of the species.
Severe weather events also pose a threat.