Phalacrocorax aristotelis

Taxonomy

Assessment Information

Geographic Range

Habitat and Ecology

Threats

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Taxonomy [top]

Kingdom	Phylum	Class	Order	Family
ANIMALIA	CHORDATA	AVES	PELECANIFORMES	PHALACROCORACIDAE

Scientific Name:

Phalacrocorax aristotelis

Species Authority:

(Linnaeus, 1761)

Common Name/s:

English

–

European Shag, Shag

Assessment Information [top]

Red List Category & Criteria:

Least Concern ver 3.1

Year Assessed:

2009

Assessor/s:

BirdLife International

Reviewer/s:

Bird, J., Butchart, S.

Justification:
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.

History:

2008	–	Least Concern
2004	–	Least Concern

Geographic Range [top]

Range Description:	The European Shag can be found along the entire Atlantic coast of Europe as far north as Finland and including Iceland, as far south as the coast of Morocco, and ranges in the entire Mediterranean nesting on parts of the coastline of most European (e.g. Italy, Turkey) and north African countries (e.g. Algeria, Libya), as well as parts of the Black Sea coast (e.g. Ukraine)¹.
Countries:	Native: Albania; Algeria; Belgium; Bulgaria; Croatia; Cyprus; Egypt; Faroe Islands; France; Germany; Gibraltar; Greece; Iceland; Ireland; Italy; Libyan Arab Jamahiriya; Macedonia, the former Yugoslav Republic of; Morocco; Netherlands; Norway; Portugal; Russian Federation; Slovenia; Spain; Tunisia; Turkey; Ukraine; United Kingdom Vagrant: Austria; Bosnia and Herzegovina; Czech Republic; Denmark; Finland; Iraq; Kazakhstan; Liechtenstein; Malta; Montenegro; Poland; Romania; Serbia; Sweden; Switzerland; Syrian Arab Republic
Range Map:	Click here to open the map viewer and explore range.

Habitat and Ecology [top]

Habitat and Ecology:	Behaviour The European Shag is a coastal species that shows high nesting site fidelity. It feeds exclusively diurnally, and one bird is always present with the clutch or brood during the breeding season. The species breeds in colonies¹ that can hold more than a thousand well-spaced pairs^2,3. It is largely sedentary¹, although immatures may undergo post-breeding dispersive movements over short distances¹. Some birds undergo short-distance migrations during winter. Individuals often forage alone when away from nesting colonies and in winter^1,3, but may follow dense shoals of fish in flocks of several hundred individuals². Habitat It occupies marine habitats but does not usually occur far from land¹. It shows a strong preference for rocky coasts and islands¹ with adjacent deep, clear water², and forages over sandy and rocky seabeds¹. It also prefers sheltered fishing grounds such as bays and channels, although it generally avoids estuaries, shallow or muddy inlets and fresh or brackish waters⁵. Diet The species feeds on a wide range of benthic, demersal and schooling, pelagic fish. Sandeels (Ammodytidae) are the dominant prey of birds in British and some Spanish populations^8,9,11,12, and are consistently present in the species' diet in most other locations studied. These are usually caught at, or near, the sea bed¹². Other prey species include fish of the families Gadidae, Clupeidae, Cottidae, Labridae, and Trisopterus spp.¹, although birds also take small numbers of polychaetes, cephalopods, other molluscs and small benthic crustaceans⁵. Adults provision their chicks with sandeels, but consume a broader variety of prey for themselves¹¹. The Mediterranean subspecies feeds mainly on coastal fishes, caught from the bottom or mid water over rocky or sandy seabeds, but economically important fish seem to form a very small part of the diet¹³. Breeding site The nest is constructed of marine vegetation and flotsam^1,2, from just above the high water level to over 100 m high³ on ledges, in crevices or in caves on sea cliffs, rocks and stacks, and at the base of sea cliffs amongst boulders¹. Foraging range At Islas Cíes, Spain, birds foraged within 20 km of the colony all year round⁸. During the breeding season, the foraging range was typically within 4 km of the colony, and birds foraged in groups of 300-1000 individuals⁸. Foraging areas tend to coincide with areas of sandy benthic sediment^8,10,11, and occur where depth is less than 80 m^9,10. At the Isle of May, Scotland, over 90% of foraging occurred within 13 km of the colony, and the maximum distance recorded was 17 km¹⁰. Foraging individuals visited more than one area during a trip, often feeding at sites several kilometres apart¹⁰. Birds were often found feeding in areas of strong tidal flow¹⁰. The available data on European Shag feeding habitat suggest that, within the inshore zone as a whole, the species is fairly plastic in its habitat requirements. In some areas, the birds' foraging range is considerably less than 20 km; the small number of birds breeding at Hirta, Scotland, all appeared to forage within a 2 km radius¹¹. Similarly, birds were only present within 3 km of North Rona, Scotland¹¹.
Systems:	Terrestrial; Freshwater; Marine

Habitat and Ecology:

Behaviour The European Shag is a coastal species that shows high nesting site fidelity. It feeds exclusively diurnally, and one bird is always present with the clutch or brood during the breeding season. The species breeds in colonies¹ that can hold more than a thousand well-spaced pairs^2,3. It is largely sedentary¹, although immatures may undergo post-breeding dispersive movements over short distances¹. Some birds undergo short-distance migrations during winter. Individuals often forage alone when away from nesting colonies and in winter^1,3, but may follow dense shoals of fish in flocks of several hundred individuals². Habitat It occupies marine habitats but does not usually occur far from land¹. It shows a strong preference for rocky coasts and islands¹ with adjacent deep, clear water², and forages over sandy and rocky seabeds¹. It also prefers sheltered fishing grounds such as bays and channels, although it generally avoids estuaries, shallow or muddy inlets and fresh or brackish waters⁵. Diet The species feeds on a wide range of benthic, demersal and schooling, pelagic fish. Sandeels (Ammodytidae) are the dominant prey of birds in British and some Spanish populations^8,9,11,12, and are consistently present in the species' diet in most other locations studied. These are usually caught at, or near, the sea bed¹². Other prey species include fish of the families Gadidae, Clupeidae, Cottidae, Labridae, and Trisopterus spp.¹, although birds also take small numbers of polychaetes, cephalopods, other molluscs and small benthic crustaceans⁵. Adults provision their chicks with sandeels, but consume a broader variety of prey for themselves¹¹. The Mediterranean subspecies feeds mainly on coastal fishes, caught from the bottom or mid water over rocky or sandy seabeds, but economically important fish seem to form a very small part of the diet¹³. Breeding site The nest is constructed of marine vegetation and flotsam^1,2, from just above the high water level to over 100 m high³ on ledges, in crevices or in caves on sea cliffs, rocks and stacks, and at the base of sea cliffs amongst boulders¹. Foraging range At Islas Cíes, Spain, birds foraged within 20 km of the colony all year round⁸. During the breeding season, the foraging range was typically within 4 km of the colony, and birds foraged in groups of 300-1000 individuals⁸. Foraging areas tend to coincide with areas of sandy benthic sediment^8,10,11, and occur where depth is less than 80 m^9,10. At the Isle of May, Scotland, over 90% of foraging occurred within 13 km of the colony, and the maximum distance recorded was 17 km¹⁰. Foraging individuals visited more than one area during a trip, often feeding at sites several kilometres apart¹⁰. Birds were often found feeding in areas of strong tidal flow¹⁰. The available data on European Shag feeding habitat suggest that, within the inshore zone as a whole, the species is fairly plastic in its habitat requirements. In some areas, the birds' foraging range is considerably less than 20 km; the small number of birds breeding at Hirta, Scotland, all appeared to forage within a 2 km radius¹¹. Similarly, birds were only present within 3 km of North Rona, Scotland¹¹.

Systems:

Terrestrial; Freshwater; Marine

Threats [top]

Major Threat(s):	The species is persecuted (e.g. shot, intentionally drowned or poisoned) at commercial fisheries and fish farms as it is perceived to be a threat to fish stocks^{4, 5}. It also suffers predation at nesting colonies by introduced American mink Neovison vison⁵, is vulnerable to coastal oil pollution^{5, 8}, locally suffers from accidental entanglement and subsequent drowning in gill-nets (fishing nets)^{5, 6}, and is susceptible to the Newcastle disease so may be threatened by future outbreaks of the virus⁷. Utilisation Eggs, chicks and adults are taken from colonies for food⁵.

Major Threat(s):

The species is persecuted (e.g. shot, intentionally drowned or poisoned) at commercial fisheries and fish farms as it is perceived to be a threat to fish stocks^{4, 5}. It also suffers predation at nesting colonies by introduced American mink Neovison vison⁵, is vulnerable to coastal oil pollution^{5, 8}, locally suffers from accidental entanglement and subsequent drowning in gill-nets (fishing nets)^{5, 6}, and is susceptible to the Newcastle disease so may be threatened by future outbreaks of the virus⁷. Utilisation Eggs, chicks and adults are taken from colonies for food⁵.

Citation:	BirdLife International 2009. Phalacrocorax aristotelis. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloaded on 09 February 2012.
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