Manx Shearwater - 2003-07

The Manx Shearwater colonies of the Pembrokeshire islands total around 50% of the world population, with around 120,000 pairs on Skomer, 45,000 pairs on Skokholm and 4,000 pairs on Ramsey. Because of the importance of this Shearwater (in European and indeed World terms) these island have been designated a Special Protection Area for them (under the EC Directive on the conservation of wild birds (79/409/EEC)

They are very difficult to census accurately and methods have changed over the years, from simple estimates based on counts of birds seen at night, estimates of burrow densities through capture/recapture methods derived from known numbers of ringed birds, through to the present day estimates based on counts of burrows and the responses of adult birds to tape recordings of their calls. Each method has been refined and compared but throughout there has been strong evidence of a continuing slow increase in the populations in the last fifty years, perhaps with an indication of a reverse of this in the early 2000’s.

On Ramsey Island the small population (perhaps 1,500 – 2,000 pairs) has risen rapidly since the Brown Rats were removed in 2000. In 2008 the population was estimated as 4,000 pairs.

Steve Sutcliffe.

Fieldwork 2003-07

Red = breeding confirmed = 3

Total tetrads in which registered = 3

Fulmar - 2003-07

Fulmars are now one of the commonest breeding seabirds around the coast of the UK but only a century ago were virtually unheard of as far south as Pembrokeshire. Their spectacular spread around the coast of the British Isles in the last century  and a half is one of the best documented of any bird species. The Seabird 2000 survey estimated that there were just under 538,000 apparently occupied sites in Britain and Ireland.

In Pembrokeshire Fulmars can now be found virtually everywhere around the coastline. They nest on sheer cliff faces on small ledges in small groups and sometimes as individual pairs.  Near Saundersfoot they nest behind the tangled roots of cliff edge trees, on the predator free islands sometimes on wide accessible ledges but always they try to find as much height as they can.  Only where the cliffs are comprised of low sloping sandstone or are exposed fully to the glare of the sun are they absent. They are fairly easy to count as they occupy their sites for many months each year, and are only totally absent in September and October when they are at sea moulting.

The number of occupied sites increased steadily in the county from the first known breeding site at Flimston in 1940, to what seems to be a discernable peak of near to 2,500 sites in the mid to late 1990’s.  Annual counts are very variable as many of the sites are occupied by non breeding or prospecting pairs.

Between the counts from 1985-88 and the Seabird 2000 counts, Fulmar numbers in the county jumped from 1,409 sites to almost exactly 2,500 sites. However these totals  mask the changes from 1996, when detailed annual counts on Ramsey, Skomer, Skokholm, Castlemartin, St Margaret’s and Caldey, suggest that the trend in subsequent years has been at best stability and more probably the population is showing a tendency to a steady decline. The distribution maps also show a decline in tetrad occupancy

Steve Sutcliffe

Fieldwork 2003-07 (based on 490 tetrads)

Red = breeding confirmed = 61

Orange = breeding probable = 6

Yellow = breeding possible

Total tetrads in which registered = 67 (13.7%)

Great Crested Grebe - 2003-07

Great crested grebes were first proved to have bred in Pembrokeshire when a pair incubated eggs at Llys-y-fran Reservoir in 1996, the nest later being predated. Although present there in following years, breeding was not proven again until 2004. A pair present with three juveniles in July 2002 was suggestive but at that date they could have come from elsewhere.

Single pairs occupied Rosebush Reservoir from 1995 onwards and were seen to have hatched a chick in 1997. They may well have attempted breeding there in each subsequent year, it being confirmed in 1999, 2002, 2004 and 2006.

Breeding was attempted at Heathfield Gravel Pit in 2005 but was unsuccessful.

Graham Rees

Little Grebe - 2003-07

The little grebe inhabits still fresh waters in the breeding season so is absent from the county’s fast flowing streams and rivers. It is secretive and inconspicuous around the breeding area and can easily be overlooked, however its distinctive far–carrying, whinnying call often betrays its presence. The nest is a floating platform of vegetation which is anchored to reeds and overhanging branches.

Comparison of the results of the two surveys indicates an almost four-fold increase in the number of occupied tetrads during the elapsed period. Most pairs were recorded on well-vegetated farm ponds used for irrigation, where there is an abundance of food in the form of small fish and invertebrates. Many of the ponds used in 2003-07 had only recently been constructed in the 1980’s but have subsequently matured, becoming vegetated and therefore suitable for Little Grebes.

Although most small waters are used by just one breeding pair, some tetrads encompass more than one such body of water and at Marloes Mere for instance, there have been four breeding pairs. Allowing for these variables, the county total was estimated to be about 70 pairs by 2007, compared to 12 pairs in 1988.   

Graham Rees

 

Fieldwork 2003-07 (based on 490 tetrads)

Red = breeding confirmed = 31

Orange = breeding probable = 9

Yellow = breeding possible = 11

Total tetrads in which registered = 51 (10.4%)

Pheasant - 2003-07

The Pheasant is an Oriental species which was introduced into Pembrokeshire about 1586, and has since naturalised. Considerable numbers are reared and released each year for shooting purposes and this has been the case for many years. Some have survived the shooting seasons to breed in a wild state and this is the population which the local surveys have attempted to assess.

The 2003-07 survey found there had been a 21% increase in distribution since 1984-88, suggesting there were about 1,630 nests by the end of 2007 compared to 1,350 in 1988, using the mean of the estimate ranges. This is expressed as nests rather than pairs as male Pheasants habitually have several mates. They were absent from the higher parts of the Preseli Hills during both surveys.

Introduced to the islands of Skomer and Caldey, they were found there during both surveys.  They possibly bred on Ramsey during the 1984- 88 period, having presumably reached it unaided, but were not recorded there in 2003-07.

Graham Rees

Fieldwork 2003-07 (based on 490 tetrads)

Red = breeding confirmed = 29

Orange = breeding probable = 225

Yellow = breeding possible = 54

Total tetrads in which registered = 308 (62.9%)

Quail - 2003-07

Small numbers of quail are detected in Pembrokeshire most summers. Usually they are located by call, only rarely are nests found and most probably do not attempt to breed. The number registered during the two five year surveys are typical of the normal level and pattern of occurrence in the county. Greater numbers are encountered during infrequent “invasion years”.  The last time this was experienced was in 1989 when at least 80 were recorded and both eggs and young were found.

Graham Rees

Fieldwork 2003-07 (based on 490 tetrads)

Red = breeding confirmed = 0

Orange = breeding probable = 11

Yellow = breeding possible = 1

Total tetrads in which registered = 12 (2.5%)

Grey Partridge - 2003-07

Considered to be fairly common in Pembrokeshire at the end of the 19^th century, the grey partridge was in decline by the middle of the 20^th century. By the time of the 1984-88 survey it was barely hanging on, surviving only because of additional birds released for shooting. The position remained precarious at the time of the 2003-07 survey and it is doubtful that a self sustaining population existed. Most modern farming practices produce conditions which do not suit Grey Partridges.

Graham Rees

Fieldwork 2003-07 (based on 490 tetrads)

Red = breeding confirmed = 2

Orange = breeding probable = 0

Yellow = breeding possible = 3

Total tetrads in which registered = 5 (1%)

Red-legged Partridge - 2003-07

The county population of red-legged partridge is sustained by annual releases for the purpose of shooting. Those birds which survive the shooting season are able to breed but it is doubtful that a self sustaining population would endure without further releases. Comparing the results of the two surveys indicates a fivefold increase but in the absence of information on the scale of releases, which appears to be unregulated, it is impossible to meaningfully interpret these findings.

Graham Rees

Fieldwork 2003-07 (based on 490 tetrads)

large dots = breeding confirmed = 5

Medium dots = breeding probable = 8

Small dots = breeding possible = 12

Total tetrads in which registered = 25 (5.1%)

Tufted Duck - 2003-07

In the breeding season tufted ducks favour lowland fresh waters of moderate depths in the range two to five metres.

In Pembrokeshire, a wild bird bred with a captive one in 1988 but a fully wild pair hatched young at Marloes Mere in 1996 and again in 1997 and 1999. None were found breeding during the 1984-88 survey but in the 2003-07 period a pair produced a brood at Skomer in 2005 and again in 2006 and 2007. Probable breeding was also registered at Marloes Mere, Bosherston and Rosebush Reservoir with breeding season presence noted near St David’s.

Graham Rees

Fieldwork 2003-07 (based on 490 tetrads)

Red = breeding confirmed =1 

Orange = breeding probable = 3

Yellow = breeding possible = 1

Total tetrads in which registered = 5 (1%)

Shoveler - 2003-07

Shoveler have nested at several localities in the county in the past but in the last twenty years seem to have become confined to three places. During the 1984-88 survey breeding was confirmed at Skomer and Marloes Mere. The 2003-07 survey found confirmed nesting at Skomer and probable breeding at Skokholm and Marloes Mere.

Graham Rees

Fieldwork 2003-07

Red = breeding confirmed = 1

Orange = breeding probable = 1

Total tetrads in which registered = 2

Mallard - 2003-07

Mallard nest largely around fresh water but have shown a capability to use sites well away from water. They have also readily adapted to artificial sites, perhaps epitomised here in Pembrokeshire, by sitting on eggs aboard a working lobster–fishing boat throughout its mobile working days.

An estimate of 400 nests was made during the 1984-88 survey, though at the time this was thought to be a little conservative. Interpolation from the findings of 1988-91 National Atlas provides a figure of 460 nests for Pembrokeshire. The BBS suggests there has been a 15% decrease in population in Wales over the period 1994–2007. However, the evidence from the 2003-07 county survey is of a 27% expansion in distribution, suggesting there could have been about 500 nests by 2007. The estimates are expressed as nests rather than pairs, as male Mallards normally take no part in incubation or tending young.

Graham Rees

Fieldwork 2003-07 (based on 490 tetrads)

Red = breeding confirmed = 100

Orange = breeding probable = 57

Yellow = breeding possible = 76

Total tetrads in which registered = 233 (47.6%)

Teal - 2003-07

Historically the teal has only sporadically bred in Pembrokeshire. It was found breeding at just one locality during the 1984-88 survey. None were found nesting during the survey of 2003-07, although there was a single record of a bird displaying at Marloes Mere.

Graham Rees