European Shag (Phalacrocorax aristotelis)

[order] SULIFORMES | [family] Phalacrocoracidae | [latin] Phalacrocorax aristotelis | [UK] European Shag | [FR] Cormoran huppe | [DE] Krahenscharbe | [ES] Cormoran Monudo | [NL] Kuifaalscholver

Subspecies

Genus

Physical charateristics

Medium-sized, slender-billed, marine cormorant with oily-green plumage and yellow gape. Sexes alike but noticeable seasonal differences; adult?s forward-curving crest present only in breeding season. At close range adult unmistakable and immature differs from young Cormorant in smaller size, slimmer build, much slenderer bill, and (except for Mediterranean race) much less white on brown breast, though sometimes white spot on chin. At longer ranges, sometimes difficulty in distinguishing these 2 species, particularly immatures but also adults if white patches on Cormorant cannot be seen. At all times, however, slimmer build, shorter neck, smaller head, and faster wing-beats of Shag help identification.

Range

Eurasia : West coasts, also North AF

Habitat

Breeds in small deepenings, niches, grottoes and cornices in the high sheer and rocky areas of the Crimean coast. Separate colonies are common, but sometimes mix with Cormorants, Yellow-legged Gulls and Rock Doves. The two kilometre water zone along the Black Sea coast is the principal feeding habitat. Small sea fish comprise its basic diet; copepods are also consumed. The major limiting factors are disturbance at the breeding sites, water pollution by oil products and solid domestic waste.

Reproduction

Breeding resident species. Arrival in the colony area depends on the weather and is prolonged from late February to early April. Breeding density and altitude (3-15 m) vary. Clutch size 2-3, infrequently 4 eggs. Egg-laying is prolonged up to more than 2 months. After the leaving of the nest birds occur in the surroundings of the colony. Second year birds, making in some areas up to 30-50% of the total numbers, keep to the colonies too. The best assimilated feeding habitat is the 200 metre strip of the sea along the shore-line. Gobies (Gobiidae) and scads (Carangidae) predominate in the diet.

Feeding habits

Chiefly and often entirely fish (chiefly midwater to lesser extent bottom-living species from coastal and estuarine areas) caught between mandibles under water and brought to surface, though occasionally swallowed below, especially if small. Typically surface-diver, but plunging from air, especially in rough water, also recorded. May spring clear of water before diving or, particularly when laden with fish, slide under surface without preliminary leap.

Conservation

This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Phalacrocorax aristotelis breeds in coastal areas of north-western and southern
Europe, which constitutes >75% of its global breeding range. Its European breeding
population is relatively small (<81,000 pairs), but increased substantially between 1970-1990. Although it was stable or increased in most countries during 1990-2000, there were declines in the United Kingdom, and the species underwent a moderate decline (>10%) overall.
This cormorant inhabits the rocky coasts of Europe and North Africa. The race desmarestii belongs to the Mediterranean and Black seas. Unlike the nominate race, inhabiting the Atlantic coasts, it undergoes a steady decline and its population inside the European Union is now reduced to a mere 3000-3500 breeding pairs

Migration

Dispersive, some adults perhaps resident. All European Atlantic populations show coastwise dispersal, though this not normally so extensive as in sympatric Cormorant, for Shag more closely associated with rocky coasts. Icelandic population believed resident. Those breeding Murmansk partially resident, but some move south-west around Norwegian coasts as far as 65 degrees N.
Populations of Mediterranean and Black Sea mainly resident, but some disperse; movement in Black Sea follows fish shoals.

Distribution map