Shag – 2003-07 breeding

Phalacrocorax aristotelis – MULFRAN WERDD – Breeding resident and passage migrant

Comparison with previous atlas:

1984-882003-07
Breeding confirmed2827
Breeding probable43
Breeding possibleexcluded from totalexcluded from total
No of tetrads occupied32 (of 478)30 (of 490)
Percentage of tetrads6.7%6.1%

Shags are essentially inshore feeding birds that prefer rocky coastlines.  Their nests are well-distributed around Pembrokeshire, with concentrations on the offshore islands. 

Despite being relatively common around the coastline, breeding Shags are not very easy to count accurately because they nest in deep crevices and so can be almost invisible.  Also some sites are not commonly visited or counted. The population has fluctuated considerably in the last fifty years with a low point during the late 1980’s and early 1990’s. The reasons for that decline are unknown but it was seen in all areas of the county. The Sea Empress oil spill in 1996 caused the death of a small number of Shags, mainly around the entrance to Milford Haven and around the south coast of the county.  The counts in 2008 were the highest since the early 1970’s and reflect high breeding success during recent years.

Only about 200 pairs currently breed in the county. The overall impression is, however, of a small but vibrant population which is doing well in the first decade of this century.

Steve Sutcliffe.

Records extracted from the Pembrokeshire Bird Reports, which may contain more detail than shown here.

More about the Shag in Pembrokeshire

Shag – 1994

Phalacrocorax aristotelis – MULFRAN WERDD – Breeding resident and passage migrant

1984-88
Breeding confirmed28
Breeding probable4
Breeding possibleexcluded from total
No of tetrads occupied32 (of 478)
Percentage of tetrads6.7%

Mathew (1894) noted colonies of Shags at Ramsey, St Margaret’s Island, Caldey and Elegug Stacks, Lockley et al. (1949) adding Skomer, Skokholm, Grassholm and Middleholm. 

In 1969, during Operation Seafarer, 121-126 nests were found. During 1985-1987 the Seabird Register found 96 nests. Colonies vary in size, from single nests to between 25 and 37, the largest being found at Grassholm, St Margaret’s Island and Middleholm, though numbers do not remain stable.

More maritime than the Cormorant, Shags can be found feeding in deeper water all around the Pembrokeshire coastline and islands as far out as the Smalls.  They regularly fish in the Cleddau Estuary, penetrating upstream as far as Beggar’s Reach, occasionally further, or in the side pills during prolonged stormy weather.

Shags are seen throughout the year but ringing has shown that there is widespread dispersal of breeding birds, especially the young. Some move towards North Wales but most towards the Bristol Channel. A few reach the English Channel, the Bay of Biscay and Spain.  A southwards passage through St George’s Channel occurs each autumn and ringing recoveries indicate that these birds come from at least as far as Gwynedd.   

Donovan J.W. & Rees G.H, 1994, Birds of Pembrokeshire

More about the Shag in Pembrokeshire

Shag – 1980s winter

Phalacrocorax aristotelis – MULFRAN WERDD – Breeding resident and passage migrant

The BTO winter atlas showed that Shags were present in all coastal and two estuarine 10km squares during the winters of 1981-82, 1982-82 and 1983-84.

The colour for each 10km square represents 1-10 birds seen in a day.

Graham Rees. Pembrokeshire County Bird Recorder 1981-2007

Data collected by volunteers for the BTO. Lack, P. 1986 Atlas of wintering birds in Britain and Ireland. T & A.D. Poyser.

More about the Shag in Pembrokeshire

Shag – 1949

Phalacrocorax aristotelis aristotelis

Common resident, more numerous than Cormorant.  Mathew gives the following breeding stations: Ramsey, Skomer, St Margaret’s Island, the channel side of Caldey, and in a cave on the west side of the great Stack.   A pair usually breeds at Skokholm and others at Grassholm and Middleholm, and along the whole coast there are scattered pairs.

R.M.Lockley, G.C.S.Ingram, H.M.Salmon, 1949, The Birds of Pembrokeshire, The West Wales Field Society

More about the Shag in Pembrokeshire

Shag – 1894

Phalacrocorax graadus

A common resident; perhaps even more numerous than the Cormorant.

There are small colonies on St. Margaret’s Island, and on the Channel side of Caldy Island, near Tenby; on Skomer and Ramsey Islands, and at various places on the coast. Mr. Dix, who paid a visit to the Stack Rocks to see the enormous numbers of Guillemots that frequent them in the summer, states that on the west side of the Great Stack is a cave, in which Shags breed in safety, as it is perfectly inaccessible.

Mathew M.A. 1894, Birds of Pembrokeshire and its Islands

More about the Shag in Pembrokeshire

Shag

Phalacrocorax aristotelis – MULFRAN WERDD – Breeding resident and passage migrant

Shag – 2020-21 WeBS

The latest totals from the Wetland Bird Survey in Pembrokeshire – and the average counts for the past ten seasons.

Shag – 2003-07 breeding

Phalacrocorax aristotelis – MULFRAN WERDD – Breeding resident and passage migrant Comparison with previous atlas: 1984-88 2003-07 Breeding confirmed 28 27 Breeding probable 4 3 Breeding possible excluded from total excluded from total No of tetrads occupied 32 (of 478) 30 (of 490) Percentage of tetrads 6.7% 6.1% Shags are essentially inshore feeding birds that […]

Shag – 1994

Phalacrocorax aristotelis – MULFRAN WERDD – Breeding resident and passage migrant 1984-88 Breeding confirmed 28 Breeding probable 4 Breeding possible excluded from total No of tetrads occupied 32 (of 478) Percentage of tetrads 6.7% Mathew (1894) noted colonies of Shags at Ramsey, St Margaret’s Island, Caldey and Elegug Stacks, Lockley et al. (1949) adding Skomer, Skokholm, Grassholm […]

Shag – 1980s winter

Phalacrocorax aristotelis – MULFRAN WERDD – Breeding resident and passage migrant The BTO winter atlas showed that Shags were present in all coastal and two estuarine 10km squares during the winters of 1981-82, 1982-82 and 1983-84. The colour for each 10km square represents 1-10 birds seen in a day. More about the Shag in Pembrokeshire

Shag – 1968-72 breeding

Red = breeding confirmed Orange = breeding probable Yellow = breeding possible More about the Shag in Pembrokeshire

Shag – 1949

Species account from the Birds of Pembrokeshire, 1949, by Lockley, Ingram and Salmon.

Shag – 1894

Phalacrocorax graadus A common resident; perhaps even more numerous than the Cormorant. There are small colonies on St. Margaret’s Island, and on the Channel side of Caldy Island, near Tenby; on Skomer and Ramsey Islands, and at various places on the coast. Mr. Dix, who paid a visit to the Stack Rocks to see the enormous numbers of Guillemots that frequent them […]