The ashy storm petrel (Oceanodroma homochroa) is a small, scarce seabird of the storm petrel family Hydrobatidae. It breeds colonially on islands off the coasts of California and Mexico, and is one of six species of storm petrel that live and feed in the rich California Current system. Ashy storm-petrels are mostly dark grey, medium-sized birds with forked tails and proportionally larger wings. Ashy storm petrels nest in the natural rock crevices found on offshore islands. At sea, the petrels live within the California Current System, preferring the near-shore waters of the continental slope. Ashy storm petrels make use of the abundant surface food provided by upwellings of the California Current System. They feed by night, catching small fish and plankton. The ashy storm petrel is designated as a species of conservation concern in California. It is threatened by western gull and burrowing owl predation, illumination from fishing boats, introduced predators such as rats and feral cats, and pollution. Near the nest, both sexes give a squeaky, harsh, descending deer-deer-deer-deer. They are typically silent at sea. Here is a link so you can listen to this bird too.