Swinhoe's storm-petrel

How it lives

It breeds in burrows on small islands in the Yellow Sea and South China Sea region. It is strictly nocturnal at the colonies, to avoid gulls and skuas, and it avoids landing on bright moonlit nights. Males give harsh chatter calls, while females give clear, bright ones, which is unusual among petrels. Outside the breeding season it lives at sea.

Where it goes

After breeding in the northwest Pacific, it is strictly a bird of the open sea and winters in the northern Indian Ocean, including the Arabian Sea. Four birds fitted with geolocators were tracked about 6,700 km between their breeding and wintering areas, and the whole seasonal journey was over 12,000 km. A small number turn up in the Atlantic and Mediterranean as rare visitors, so records in places such as Portugal or the UK are exceptions.

We only draw a journey on the map when scientists have tracked it or clearly documented it. For this animal we have not found one yet.

Populations

Near Threatened worldwide. The IUCN moved it up from Least Concern in 2012, because a moderate decline is expected, mainly from introduced species at colonies. A 2010 estimate (Sato et al.) gave at least 130,000 breeding pairs, and about 100,000 pairs may nest on one small islet in South Korea (Gugeul), which would be over 75% of the world population. Other colonies are far smaller: about 7,500 pairs on Verkhovsky Island (Russia), at least 1,000 pairs in Japan, and about 7,900 pairs on Chilbaldo (South Korea). There is anecdotal evidence that some colonies are declining. No breeding colony has been confirmed in the Atlantic.