WatchList Species Account for Black Storm-Petrel (Oceanodroma melania)

Qualifies for the list as a Red List Species

Photo: Glen Tepke

The Black Storm-Petrel breeds only on a few islands off the coast of southern California and Baja California; in the latter its colonies are both off the Pacific Coast and in the Gulf of California. Like other storm-petrels, it nests in burrows and makes nocturnal visits to feed its single young. Breeding populations have been greatly affected by the introduction of cats and rats to the islands and adults are taken by Peregrine Falcons and by gulls.

During nonbreeding, part of the population moves northward to waters off central and southern California, while the majority move south to waters off Central America and northern South America. The bird numbers in the millions of pairs but introduced predators are a constant threat. Most now breed on the Islas Benitos off the Pacific Coast of Baja California.

Rats have been eradicated from 6 islands off Los Angeles and cats have been eradicated from 7 islands along the Pacific Coast and 7 potential breeding islands in the Gulf of California. Rabbits and goats have been eradicated from the 3 Islas San Benitos and goats and sheep from Natividad. A developing problem in the Channel Islands of California is the great increase of squid-fishing vessels close to shore during the summer. These use powerful lights and may cause greater predation by owls on small seabirds such as the Black Storm-Petrel.

Eggshell thinning due to elevated pesticide levels has been observed in the Ashy Storm-Petrel at Santa Cruz Island, and the same problem could be affecting the Black Storm-Petrel. Oil spills and pollution are potential threats to the species. Further research on the species as facilitated by mist-netting and banding is needed to understand the metapopulation dynamics of the birds.