Ainley's storm petrel is a species of seabird in the family Hydrobatidae. It breeds in the winter on Guadalupe Island off the western coast of Mexico. It ranges south to the Galápagos Islands. It is considered by some authorities to be a subspecies of Leach's storm petrel.
Region
Eastern Pacific Ocean
Typical Environment
Breeds on Guadalupe Island off northwestern Mexico and disperses widely over the eastern tropical and subtropical Pacific, ranging south at sea to waters around the Galápagos. Strongly pelagic outside the breeding season, occurring far from land over deep offshore waters. At the colony it uses rock crevices and burrows in sparsely vegetated slopes and cliffs. It forages over productive current edges and upwelling zones and may follow surface-feeding fish or marine mammals.
Altitude Range
Sea level to 600 m
Climate Zone
Subtropical
Ease of Keeping
Beginner friendly: 1/5
Ainley's storm petrel is a small, elusive seabird that breeds in winter on Guadalupe Island, Mexico. Long treated as part of the Leach's storm petrel complex, many authorities now recognize it as a distinct species. It is difficult to identify at sea and is most reliably detected at nocturnal breeding colonies. Key threats include introduced predators and light pollution near colonies.
Temperament
pelagic, nocturnal at colonies, secretive near nests
Flight Pattern
buoyant with quick fluttering wingbeats and short glides
Social Behavior
Nests in loose colonies, forming monogamous pairs that reuse burrows across seasons. Strictly nocturnal at the colony to avoid predation, arriving silently and calling from within burrows. Both parents share incubation and chick-rearing duties.
Migratory Pattern
Seasonal migrant
Song Description
At sea it is generally silent. At colonies it gives low, purring and chatter-like calls, often delivered from inside burrows, with soft, rhythmic sequences that carry on calm nights.
Plumage
Mostly sooty-brown to blackish with a crisp white rump and a slightly forked tail; shows a pale, narrow upperwing bar. Feathers appear velvety with subtle contrast between mantle and wings. A faint dark median line may bisect the rump in some individuals.
Diet
Feeds mainly on small fish, squid and their larvae, and planktonic crustaceans such as copepods and euphausiids. Often picks prey from the surface while pattering its feet on the water and may seize items flushed to the surface by predators. Will occasionally take oily scraps or natural slicks associated with productive waters.
Preferred Environment
Open ocean over deep waters, especially along upwellings, fronts, and shelf edges. Frequently forages far offshore but can be concentrated near productive current systems and around colonies when provisioning chicks.
