European Storm Petrel

European Storm Petrel

British storm petrel, Storm petrel

Kingdom
Phylum
Class
Family
Genus
SPECIES
Hydrobates pelagicus
Population size
430-520 Thou
Life Span
11-33 years
Weight
20-38
0.7-1.3
goz
g oz 
Length
14-18
5.5-7.1
cminch
cm inch 
Wingspan
36-39
14.2-15.4
cminch
cm inch 

The European storm petrel (Hydrobates pelagicus) is a seabird in the northern storm petrel family, Hydrobatidae. These birds nest in crevices and burrows and sometimes share them with other seabirds or even rabbits. The adults share the lengthy incubation and both feed the chick, which is not normally brooded after the first week. The presence of storm petrels in rough weather at sea has led to various mariners' superstitions, and by analogy, to their use as a symbol by revolutionary and anarchist groups.

Appearance

The European storm petrel is square-tailed and has all-black plumage except for a snow-white rump that extends to the sides of the tail base and a broad white band on the under wings. Juveniles in fresh plumage can also show a narrow white bar on the upper wing. The plumage becomes dark brown rather than black as it becomes worn. No obvious differences between the sexes are seen, although females are slightly larger and have a longer white rump than males. The Mediterranean subspecies has longer wings and a heavier bill on average than the nominate form, but neither sex nor subspecies can be determined by observation at sea. Storm petrels have large nasal olfactory bulbs which facilitate a keen sense of smell (unlike most birds), and the birds have a distinctive musty aroma that can help researchers locate breeding colonies. Individual petrels recognize their own body scent and can use it to locate their nests in the dark.

Distribution

Geography

Storm petrels breed only in the Western Palaearctic on islands off the Atlantic and Mediterranean coasts of Europe. They are migratory, spending the Northern Hemisphere winter mainly in cool waters off the coasts of South Africa and Namibia, and east to KwaZulu-Natal. Some birds stay north of the equator in the seas adjoining Mauritania and Rio de Oro, and a few remain near the breeding islands, especially in the Mediterranean. Storm petrels are strictly oceanic outside the breeding season, although they are regularly seen from land in West Africa. Young birds do not return to the breeding colonies until their second or third year. Storm petrels breed on exposed and usually uninhabited islands. They may also frequent mid-depth waters away from the coastal zone, but not over the ocean deeps.] In Europe, they are rarely seen from land except in autumn storms.

European Storm Petrel habitat map

Climate zones

European Storm Petrel habitat map
European Storm Petrel
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Habits and Lifestyle

European storm petrels are gregarious throughout the year. They usually feed during the day, but in the breeding season, petrels will often feed at night close to the shore. Storm petrels normally fly within 10 m (33 ft) of the water surface and typically feed by picking items off the sea as they patter over the surface. They may also dive for food to a depth of not more than 0.5 m (20 in) and it is claimed that the Mediterranean subspecies reaches depths of up to 5 m (16 ft)). Storm petrels may range up to 200 km (120 mi) over the course of two or three days in search of food. Their flight is weak-looking and resembles that of a bat, with fluttering interspersed with short glides. When feeding, the birds hang with raised wings and patter on the surface with their feet, but do not look as if they are walking on the water. Birds sometimes settle on the sea. Like other petrels, European storm petrels cannot walk properly on land, but shuffle on their tarsi; once there is enough room, they flap their wings to support themselves on their toes. Storm petrels are usually silent at sea, but sometimes give a chattering call in their courtship flight, and the male has a purring song given from the breeding chamber. Other vocalizations include a fast ‘wick-wick-wick’, sometimes given in flight and an ‘up-CHERRK’ alarm which resembles the chatter-call. Chicks give a whistling ‘pee-pee-pee’ call when being fed, and a faster version of this vocalization is used by adults and young to signal distress.

Seasonal behavior
Bird's call

Diet and Nutrition

European storm petrels are carnivores (piscivores, milluscivores). They feed on small fish, squid, crustaceans, and jellyfish. They will also eat offal and oily food, often located by smell, and will follow ships. In the Atlantic, more than half the food items are zooplankton and the fish caught include small herring and sprats; whale carcasses are scavenged where available. Storm petrels also consume small numbers of insects which they catch near breeding colonies, and some plant material, including angiosperm seeds and sorrel.

Mating Habits

MATING BEHAVIOR
REPRODUCTION SEASON
starts in May/June
INCUBATION PERIOD
38-50 days
INDEPENDENT AGE
56-86 days
BABY NAME
chick
web.animal_clutch_size
1 egg

European storm petrels are monogamous. They usually mate for life and use the same hole every year. Storm petrels breed in colonies starting in late May or June. Pairs have a repeated nocturnal display flight in which the male chases the female, the chase being accompanied by flight calls. Storm petrels prefer to nest in crevices between or under rocks, or burrow in the soil. When they make their own tunnels, they loosen the earth with their bills and kick out the debris with their feet. The nest tunnel is 10-300 cm (3.9-118 in) long and 5-8 cm (2-3 in) across, with a slightly narrower entrance. The nest chamber is typically unlined, although pairs may bring in some grass, bracken, or seaweed. Although the storm petrel is generally not territorial when breeding, a pair defends the nest chamber itself after the eggs have been laid. The clutch is a single egg, usually pure white, sometimes with some reddish-brown spots that soon disappear. The egg is incubated by both parents for 38-50 days. One adult parent typically spends three days at a time on the egg while its partner feeds at sea. The chicks hatch altricial and are covered with silver-grey down, and are fed by both parents with their regurgitated oily stomach contents. The parents do not usually stay with the chick after the first week and visit only to bring food. After about 50 days, the chick is fed less regularly, sometimes with gaps of several days, and the parents may stop visiting completely shortly before the chick leaves the nest. The chick fledges about 56-86 days after hatching and receives no parental support after leaving the nest hole. Storm petrels become reproductively mature at age 4-5 years, with the Mediterranean subspecies typically breeding a year earlier than the Atlantic form.

Population

Population threats

European storm petrels are not considered threatened at present but the birds suffer natural predation from gulls, skuas, owls, and falcons.

Population number

According to IUCN Red List, the total population size of the European storm petrel is 430,000-519,999 mature individuals. In Europe, the breeding population consists of 438,000-514,000 breeding pairs, equating to 876,000-1,030,000 mature individuals or 1,314,000-1,545,000 individuals. Currently, this species is classified as Least Concern (LC) on the IUCN Red List.

References

1. European storm petrel Wikipedia article - https://en.wikipedia.org/wiki/European_storm_petrel
2. European storm petrel on The IUCN Red List site - https://www.iucnredlist.org/species/22698477/132650209
3. Xeno-canto bird call - https://xeno-canto.org/703122

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