Southern Puffin - 1949

Fratercula arctica grabae

Mathew considered it "by far the most numerous" bird on the Pembrokeshire list, describing the colony at Grassholm as contain "countless numbers" which "on rising and flying overhead, for the moment completely shaded the sun".  In 1890 J.J.Neale estimated over half a million puffins at Grassholm.  In 1946 there were scarcely 50 pairs.  The decline in numbers at Grassholm seems to be related to the great increase at Skokholm in the same period.  In the reign of Queen Elizabeth vast numbers bred on Ramsey, which has since been abandoned.  The same may be said of Caldey.  It breeds sparingly on a few isolated stacks and cliffs along the mainland coast, but its main stations are Skomer and Skokholm, where they are so numerous that is is difficult to form an estimate of the total force.  It is probably not less than one hundred thousand pairs.

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

Puffin - 2011 reserach - migration strategy

Individual Atlantic puffins 'scout out' their own migration routes rather than relying on genetic 'programming' or learning routes from a parent, a new study suggests.

The evidence comes from research by a team from Oxford University and Microsoft Research Cambridge which used BAS geolocater tags to track the migration movements of 18 birds: with 8 of these birds being tracked for two consecutive years.

The study found that the birds followed a wide range of different migration routes (suggesting their movements were not genetically predetermined) but that they were not merely random as the same bird followed a similar route each year. Because young puffins leave colonies at night, alone, long before their parents, the idea that they might learn a route directly from others also seems extremely unlikely.

'We think it's likely that, before they start breeding, young puffins explore the resources the ocean has to offer and come up with their own individual, often radically different, migration routes,' said Professor Tim Guilford of Oxford University's Department of Zoology, who co-led the study. 'This tendency to explore may enable them to develop a route which exploits all the best food sources in a particular area wherever these might happen to be.'

The team believe this kind of 'scouting' for good migration routes could also be used by many other species of birds, especially seabirds -- which can choose to stop and feed anywhere on the ocean during their migration.

The full article can be found here

Guilford T, Freeman R, Boyle D, Dean B, Kirk H, et al. (2011) A Dispersive Migration in the Atlantic Puffin and Its Implications for Migratory Navigation. PLoS ONE 6(7): e21336. doi:10.1371/journal.pone.0021336

Puffin - 2003-07

Common offshore around western Pembrokeshire between late March and late July each year, but rarely seen outside this period, they congregate in large rafts close inshore near their breeding colonies in the spring and early summer months and socialise around their breeding colonies each evening.

Puffins are mostly confined to offshore islands free of predators, particularly rats. They nest in burrows on steep slopes in sometimes very dense colonies.  The principal colonies are on Skomer Island, including Middleholm, and Skokholm with small populations on the Bishops near Ramsey, on St Margaret’s Island and at Stackpole Head where they nest in sheer cliff sites.

Numbers in the past were clearly very much higher than they are now and for example it was estimated that 500,000 to 700,000 pairs nested on Grassholm in the  1890’s,  a figure disputed by modern analysis which suggested that around 200,000 pairs would be more realistic.  Whatever the actual figure, the density was clearly much higher than in today’s colonies and on Grassholm there are still remnants of the collapsed burrows testifying to this. This colony was more or less deserted during the 1920’s and it has been suggested that the birds relocated to Skomer and Skokholm, although it is not clear how that assumption was made. There were also apparently big colonies on Caldey and Ramsey in historic times, before rats devastated them.

Mathew (1894) made the observation that they were undoubtedly the most common bird in Pembrokeshire with huge colonies on Skomer stating “ there is scarcely a yard of ground free of them” and Lockley et al (1949) thought that around 50,000 pairs were breeding on Skomer and 20,000 on Skokholm. There were clearly many more birds present than there are today. 

The population estimates which have been made since the 1950’s on both Skomer and Skokholm have been consistent in suggesting that around 9,000 to 10,500 pairs may breed there.  Estimates are however subject to substantial inaccuracies because it is not possible to count burrows, as both rabbits and shearwaters breed on both islands in abundance, and estimates have tended to be done by extrapolation of detailed studies in one small part of the islands.

Consequently, in an attempt to provide greater consistency in counting and to provide comparative long term data of population trends, all counts of birds since the 1980’s have concentrated on the maximum attendance by adult birds in the spring. The spring counts in 2003-2007 of around 10,800 individual birds on Skomer and 4,800 on Skokholm  suggests a rather similar breeding population to the 1985-87 Seabird Colony Survey estimate of a total breeding population of  about 10,600 pairs  on the two islands.

Stephen Sutcliffe

Fieldwork 2003-07 (based on 490 tetrads)

Red = breeding confirmed = 4

Orange = breeding probable = 2

Yellow = breeding possible = 0

Total tetrads in which registered = 6 (1.2%)

Puffin - 1994

Breeding summer visitor

The Puffin was formerly much more numerous than it is today. There was an extremely large colony of Puffins on Grassholm in the 1890s, estimates of its size varying from 500,000 to 700,000 pairs. However, when reviewing these estimates Williams (1978) used a density of two pairs per square yard to calculate that the population was probably about 200,000 pairs. This huge number nested in burrows in the 'haystack' of red fescue which covered most of the island to a depth of two feet. Eventually this became so honeycombed with burrows that it collapsed and Puffins largely forsook Grassholm, probably by 1920, when local opinion was that many had moved to breed on Skokholm. They bred all over the island of Skomer according to Mathew (1894) who stated "that there is scarcely a yard of ground free of them", and around the turn of the century were also breeding on Caldey, St Margaret's and the Bishops. Lloyd found a small colony of about 20 pairs breeding on Ramsey in 1927, where they bred commonly before the island was invaded by brown rats (Howells 1968). He also noted small numbers in the cliffs between Linney Head and St Govan's Head during the 1920s and 1930s.

Lockley et al. (1949) estimated that about 100,000 pairs were breeding on Skokholm and Skomer combined, but by the time of Operation Seafarer (1969) the total Pembrokeshire population was down to about 9,000 pairs and the Seabird Register survey of 1985-1987 found about 10,600 pairs (see map), so there appears to have been a recent period of stability.

Puffins arrive at the breeding area in about the middle of March, and depart the land by about the third week in August, though some are seen in inshore waters well into October. They spend the winter out to sea. Ringing recoveries indicate that the winter range extends from Greenland to Gran Canaria and across the Atlantic as far as Newfoundland.  they are rarely seen in Pembrokeshire in the winter; those birds that do occur in winter are usually sick or exhausted.

 

Fieldwork 1984-88 (based on 478 tetrads)

Red = breeding confirmed = 7

Yellow = breeding possible = 1

Total tetrads in which registered = 8 (1.7%)

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

Puffin - 1970s breeding

Red = breeding confirmed

Orange = breeding probable

Yellow = breeding possible

Puffin - 1894

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

Click to read more ...