The Leach's Petrel is a small bird at 18-21 cm in length with a 43-48 cm wingspan. It has all-dark plumage and usually a white rump. However, dark-rumped individuals exist on the west coast of North America. It can distinguished from the European Storm Petrel and the Wilson's Storm Petrel by its larger size, forked tail, different rump pattern and flight behavior. It is very hard to separate this species from Band-rumped Storm Petrels. identification involves characteristics such as the extent of white on the rump and flight pattern. This bird has a fluttering flight.
Habitat and Distribution
It is strictly pelagic outside the breeding season. Only in storms might this species be pushed into headlands. Unlike Storm-petrel, it does not follow ships. In Europe, the best chance of seeing this species is in September in Liverpool Bay between north Wales and England. Strong north-westerlies funnel migrating Leach's Petrels into this bay. It breeds on inaccessible islands in the colder northern areas of the Atlantic and Pacific.
They feed on plankton, including euphausiids, copeopods, and a form of amphipod that are parasitic to jellyfish gonadal pouches. They also eat myctophids (lantern fish) which occur at the surface at night in water over the continental slope.
It nests in colonies close to the sea in well concealed areas such as rock crevices, shallow burrows or even logs. It lays a single white egg which often has a faint ring of spots at the large end. This storm petrel is strictly nocturnal at the breeding sites to avoid predation.