Leach’s Storm-petrel

The Leach’s Storm-petrel or Leach’s Petrel (Oceanodroma leucorhoa) is a small seabird of the tubenose family. It prefers to breed on inaccessible islands in the colder northern areas of the Atlantic and Pacific. It nests in colonies close to the sea in rock crevices where it lays a single white egg.

Like other storm-petrels, it is strictly nocturnal at the breeding sites to avoid predation by gulls and skuas, and will even avoid coming to land on clear moonlit nights. Additionally, its walking ability is limited to a short shuffle to the burrow.

The Leach’s Petrel is a small bird measuring on average 18-21 cm in length with a wingspan of 43-48 cm. Despite its small size it is distinctly larger than the European Storm-petrel, which it superficially resembles with its dark plumage and white rump. It has a fluttering flight pattern, and patters on the water surface as it picks planktonic food items from the ocean surface.

It can be distinguished from the European Storm-petrel and the Wilson’s Storm-petrel by its larger size, forked tail, different rump patterns and flight behavior. Some north-eastern Pacific Leach’s Petrels show all-dark rumps.

It is strictly pelagic outside the breeding season, and this, together with its remote breeding sites, makes Leach’s Petrel a difficult bird to see from land. 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.

This bird is named after the British zoologist William Elford Leach. The average lifespan for this bird is unusually long with an average of 20 years and a maximum of 36 years. In 2003 scientists found that the bird’s telomeres lengthen with age, the only known example to date of such a phenomenon. It is rather likely, however, that this phenomenon also occurs in other members of the Procellariiformes, which all have a rather long lifespan compared to their size.