Hydrobates homochroa
The Ashy Storm-Petrel (Hydrobates homochroa) is a small, enigmatic seabird, uniformly clad in dusky-grey to sooty-brown plumage, giving it its characteristic 'ashy' appearance. Measuring approximately 18-23 cm (7-9 in) in length with a wingspan of 41-48 cm (16-19 in) and weighing 30-40 g (1.1-1.4 oz), it is a diminutive yet resilient denizen of the open ocean. Distinctive field marks include its overall dark coloration, a relatively short and slightly forked tail (less pronounced than Leach's...
Highly pelagic, inhabiting cold, productive offshore waters of the California Current system; breeds exclusively in burrows, rock crevices, or under boulders on predator-free offshore islands and rocky islets.
Primarily consumes small fish (e.g., juvenile rockfish), squid, and various zooplankton (e.g., copepods, euphausiids) picked from the ocean surface, occasionally supplemented by scraps from fishing vessels.
Ashy Storm-Petrels are largely nocturnal at their breeding colonies, arriving and departing under the cover of darkness to avoid avian predators, while at sea they are diurnal. They forage by surface-feeding, pattering their feet on the water to hold position as they dip their bills to snatch sma...
The Ashy Storm-Petrel's breeding range is strictly confined to islands and rocky islets along the coast of California, USA, and northern Baja California, Mexico. Key breeding colonies include the Farallon Islands, the Channel Islands (e.g., San Miguel, Santa Cruz, Santa Rosa, Anacapa), Año Nuevo ...
Endangered
- The Ashy Storm-Petrel is an endemic species, breeding exclusively on islands off the coast of California and Baja California. - It is almost entirely nocturnal at its breeding colonies, flying to and from its burrows under the cover of darkness to avoid predatory gulls and owls. - Despite its s...