European Storm Petrel

The European storm petrel, Hydrobates pelagicus, is a diminutive seabird with a distinctive appearance. It is characterized by its entirely black plumage, save for a broad white rump and a white band on the underwings. The bird's flight is fluttering and bat-like, and it possesses a square tail. This species exhibits sexual monomorphism, meaning males and females appear similar.

Identification Tips

Adult European storm petrels are small, measuring 14–18 cm in length with a wingspan of 36–39 cm. They weigh between 20–38 grams. The white rump and underwing band are key identification features, along with their fluttering flight pattern. Juveniles may show a narrow white bar on the upper wing. The Mediterranean subspecies, H. p. melitensis, has longer wings and a heavier bill but is indistinguishable at sea from its Atlantic relatives.

Habitat

These birds breed on remote and often uninhabited islands, preferring rocky crevices or burrows for nesting. They are strictly oceanic outside the breeding season, frequenting mid-depth waters away from the coast and avoiding deep oceanic zones.

Distribution

The European storm petrel is found in the Western Palaearctic, with significant breeding colonies in the Faroe Islands, United Kingdom, Ireland, and Iceland. The Mediterranean population, a separate subspecies, breeds in areas such as Filfla Island, Sicily, and the Balearic Islands. During the Northern Hemisphere winter, they migrate to the coasts of South Africa and Namibia.

Behaviour

Breeding typically begins in late May or June, with these birds exhibiting nocturnal display flights. They are known to mate for life and often return to the same nesting site annually. Outside the breeding season, they are oceanic and can be seen pattering on the sea's surface while feeding.

Song & Calls

The European storm petrel is usually silent at sea but has a chattering call used in courtship flights. The male also produces a purring song from the breeding chamber. Calls vary geographically, with the Mediterranean subspecies having a distinctive chatter-call.

Breeding

A single white egg is laid in a nest within crevices or burrows, with both parents sharing incubation duties. Chicks are fed with regurgitated oily stomach contents and fledge after approximately 56–86 days.

Similar Species

The European storm petrel can be differentiated from other Western Palaearctic species like Leach's storm petrel, band-rumped storm petrel, and Monteiro's storm petrel by its smaller size, darker plumage, shorter wings, and square tail. Wilson's storm petrel lacks the underwing bar and has longer legs.

Diet and Feeding

Their diet consists of small fish, squid, crustaceans, and jellyfish. They feed by picking items off the sea's surface and can locate oily food by smell. The Mediterranean subspecies primarily feeds on fish and exploits bluefin tuna farms for additional food sources.

Conservation Status

The European storm petrel is classified as Least Concern by the IUCN due to its high total numbers. However, populations may be declining slightly due to predation and introduced predators on breeding islands. Conservation efforts include rat eradication and protection against natural predators.

In Culture

The European storm petrel has been associated with mariners' superstitions, often seen as an omen of bad weather or the souls of perished sailors. Its presence in rough seas has also led to its use as a symbol by revolutionary and anarchist groups.