Pomatorhine Skua - 1949

Stercorarius pomarinus

Mathew makes the surprising statement that this "is by far the commonest of the family upon our coasts", and says a few are to be seen every autumn.  It seems likely that he confused it with the Arctic Skua.  It has not been seen Skokholm.  J.Wynne records that he has seen it twice and Mackworth-Praed states one was shot in 1914.  One was seen in Whatsands Bay, 21 Sept 1930 (D.L.Lack)

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

Pomarine Skua - 1994

Passage migrant. Not recorded in January and March

Lockley et al. (1949) knew of only four birds having been recorded in Pembrokeshire, having cast doubt on Mathew's (1894) statement that it "is by far the commonest of the family upon our coasts and a few are to be seen every autumn".

One or two have been recorded in ten of the years between 1950 and 1979. Regular seawatching at Strumble Head has since given us a new perspective on their occurrences. Table 12 shows that Mathew was indeed correct, a few are seen every autumn, between 4 August and 30 November. On some days late in the period, such as 22 November 1985 when 22 passed, and 17 October 1991 when 97 were seen followed by 130 next day, they can also be the commonest of the skuas to occur.

Observations at the Smalls revealed that one or two passed on ten days in the autumn of 1982, on seven days in 1983 and four in 1984. The only other autumn occurences away from Strumble Head during the 1980s were of a single bird off Skokholm on 16 October 1987 and a total of 10 between 10 August and 22 September 1989.

In combination these records suggest that the path of Pomarine Skuas flying out of the Irish Sea is blocked by the north coast of Pembrokeshire, and they follow this until they can head out to sea again when clear of the Bishops, a few individuals thereafter wandering inshore.

Single Pomarine Skuas have been noted in most recent springs, between 8 April and 6 June, when they have not been confined to the north coast. A flock of five passed Skokholm on 27 May 1991.

Singles were noted at Strumble Head on 8 December 1985 and at the Smalls on 28 February 1983.

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

Pomarine Skua - ageing and morphs

Stercorarius pomarinus  

Age and or morph was recorded for most Pomarine Skua sightings. Fewer adults than other ages were recorded. Adults made up 37 % of the total in the Strumble Head series between 1982 and 2003.

 When the highest day totals were recorded, on the 17th October 1991 and on the 18th October 1991, during a recovery movement in strong north–west winds, following south–west gales which had presumably displaced unusually high numbers into Cardigan Bay, only 25 % and 18 % respectively were adults, suggesting immature birds were more susceptible to the immediate effect of extreme weather.

Light- phase made up the bulk of the adult sightings, dark-phase birds amounting to less than 1% of the total.

Graham Rees

(Covers records up to and including 2006)

Pomarine Skua - spring passage

Stercorarius pomarinus

The Pomarine Skua has been of erratic occurrence in spring, involving small numbers between the 8th April and the 18th June. Singles have been recorded from Caldey, St Govan’s Head, Skokholm, Skomer, Grassholm, The Smalls, Druidston, Newgale, Ramsey and Strumble Head, with two together at Amroth on the 4th May 2003 and a party of five passed Skokholm on the 28th May 1991.

One seen at The Smalls on the 28th February 1983 may have been an early migrant or possibly over wintering in the general sea area.

Graham Rees

(Covers records up to and including 2006)

Pomarine Skua - autumn passage

Stercorarius pomarinus  .

The Arctic breeding range of the Pomarine Skua is almost circumpolar, being mainly correlated with the variable distribution of Lemmings. Migrants seen in north-west Europe are en route to or from wintering areas off west Africa, which lie largely north of the Equator.

The Pomarine Skua was first recorded for Pembrokeshire by Mathew (1894), who commented “a few are to be seen every autumn, and after heavy gales large flocks are observed.”  Lockley et al (1949) considered he could have been wrong, as they knew of only four occurrences during their time, the only one dated being on the 21st September 1930.

There were seven records involving 11 birds during the next 28 years. With the exception of 1979 they have been recorded annually since 1976. Most were seen in the autumn, between August and December and predominantly at Strumble Head.

 

N. B. The discrepancy between the 1991 total and that given by Donovan and Rees (1994) is because of additional records received since publication of that work.

Totals August to November 1980 – 2006.Values are expressed in six day intervals, the last period in months of 31 days have been adjusted from seven day totals by dividing by seven and multiplying by six.

Daily totals were small, normally involving less than 20 birds, with the following exceptions: 22 on the 20th October 1984, 30 on the 10th November 1985, 59 on the 7th October 1988, 97 on the 17th October 1991, 130 on the 18th October 1991, 20 on the 4th September 1992, 24 on the 20th October 1999, 27 on the 6th November 1999 and 21 on the 4th December 1999.

There were only six other bird days recorded in the month of December over the whole period from 1980 to 2006, the latest being on the 27th in 1990 and 1999. Early occurrences were of single birds on the 21st and 22nd July 1990 and 24th July 1998.

Away from Strumble Head, autumn records of one to four birds were noted off Fishguard, from the Fishguard to Rosslare ferry, Ramsey, Newgale, The Smalls, in the Celtic Deep, Skomer, Skokholm, St Govan’s Head and Amroth, with 11 at St David’s Head on the 5th November 1999.

Graham Rees

(Covers records up to and including 2006)

References

DONOVAN. J and REES. G. 1994. Birds of Pembrokeshire, Dyfed Wildlife Trust.

LOCKLEY. R. M, INGRAM. C. S. and SALMON. H. M.1949. The birds of Pembrokeshire, West Wales Field Society.

MATHEW. M. 1894. The birds of Pembrokeshire and its islands, R. H. Porter

Pomatorhine Skua - 1894

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

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