British Razorbill - 1949

Alca torda britannica

Mathew describes it as a common summer resident, but less numerous than Guillemot or Puffin, and mentions the folowing breeding stations: Caldey, St Margaret's, Skokholm, Skomer, Grassholm, Ramsey and various mainland cliffs.  Breeds today in suitable sites from Cemmaes Head to Caldey.  Decreased during the recent war, prabably because of oil-pollution.

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

Razorbill - 2003-07

Razorbills nest mostly in loose colonies scattered around broken cliffs in cracks and holes and less commonly on small ledges. In some places just a few birds might breed in suitable sites, so their distribution is slightly wider around the county than the gregarious Guillemot.

 There are many fewer Razorbills than either Guillemots or Puffins but they occupy many more breeding sites around the coastline, especially along the south coast of the county and between Dinas Head and Newport along the north coast.  Their distribution appears to have hardly changed during the last century.

 Razorbills are not easy to count as they nest in scattered, often well concealed, small groups.  In the late 1970s (but for some reason not on Skokholm until the late 1980) the count methodology was changed.  Now all individuals attending the colony (i.e. observed on land), are counted, rather than using the older method of estimating “apparently occupied sites”.   Accordingly population comparisons have since been made using a standard conversion factor of 0.67 across the UK, i.e. for every three birds counted there are two nest sites on average. Even so, because of the problems of seeing birds easily at some sites (where sometimes the birds are very evident and sometimes they hide very effectively, which is possibly weather related), and because of the simple variation in attendance from day to day, the census counts are at best reasonable estimates. 

 Because of these census variables, data needs to be accumulated over a long period of time to assess population changes.  Information for Razorbills at their main breding sites has been collected for more than 40 years. The counts during the Seabird Colony register in 1985 – 1988 found a population of around 6,600 individuals in the county, half of them on Skomer. Seabird 2000 counts between 1998 and 2002 showed a significant increase to c. 9,000 birds during the period 2003–07, with almost 5,000 of them on Skomer.  This is the highest known population level.

Steve Sutcliffe

 

Fieldwork 2003-07 (based on 490 tetrads)

Red = breeding confirmed = 27

Orange = breeding probable = 1

Yellow = possible breeding = not included

Total tetrads in which registered = 28 (5.7%)

Razorbill - 1994

Breeding resident and passage migrant

Breeding distribution seems to have changed little since the time of Mathew (1894). Assessing numbers, though, is even more problematical

than for Guillemot, for a large proportion breed in rock crevices where they are not readily visible.

Changes in the fortunes of the Razorbill have been very similar to those of Guillemot. Lockley et al. (1949) noted a decrease in numbers following the second World War, which they attributed to the effects of oil pollution. The population continued to decrease thereafter, with numbers on Skomer, for example, falling from about 2,100 pairs in 1963 to about 1,600 by 1974. In addition to oil pollution, Razorbills in the Irish Sea area were also casualties of toxic residue build-up (Saunders 1976). The Operation Seafarer survey of 1969 found about 3,000 breeding pairs in Pembrokeshire, about 50% of which were at Skomer.

Despite the Irish Sea seabird wreck of 1969 and oiling incidents such as those involving the Christos Bitas and Bridgeness, Razorbills began increasing again in the late 1970s and 1980s. The Seabird Register survey of 1985-1987 found about 6,600 occupied sites in Pembrokeshire, the major colonies being at Skomer (3,869), Ramsey (927), Skokholm (702), Elegug Stacks, Flimston (393), Needle Rock, Fishguard (266), Stackpole Head (138) and St Margaret's Island (154).

Flightless young and moulting adult Razorbills gather off Strumble Head with Guillemots during August and September. Ringing has shown that some Razorbills stay in home waters throughout the year, while others, particularly first year birds, wander to Ireland, Scotland, the North Sea (as far north as Norway), the English Channel, all the way down the Bay of Biscay and into the Mediterranean.

Large numbers pass southwards out of the Irish Sea between late September and early December, often mixed with Guillemots but normally greatly outnumbered by them, though a remarkable 20,000 birds were estimated to have passed Strumble Head on 25 October 1992.

Fieldwork 1984-88 (based on 478 tetrads)

Red = breeding confirmed = 24

Total tetrads in which registered = 24 (5%)

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

Razorbill - 1970s breeding

Red = breeding confirmed

Orange = breeding probable

Yellow = breeding possible

Razorbill - 1980s winter atlas

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

The darker the colour, the higher the relative total count for each 10km square.  The darkest blue represents over 17 birds.

Small numbers were found feeding in coastal waters but many more during their occasional winter time visits to breeding locations.

Graham Rees

Razorbill - 1894

Species account from M Mathew, 1894, "The Birds of Pembrokeshire and its islands"

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