Carrion Crow - 2003-07

The all black appearance of the Carrion Crow means it is easily confused with the Rook. The curved bill and lack of a bare throat differentiates it from the Rook, as does the call and keeping its nest in a discrete territory rather than in a colony. The bulky stick nest, placed high in a tree, is usually conspicuous before leaves appear. In Pembrokeshire they also nest on cliff ledges.

The estimate that accompanied the 1984-88 survey was based on the distances between nests in a small number of random localities. With no other information available at the time, this was used to calculate a county total breeding population of 18,000–21,000 pairs. With the benefit of hindsight this is now considered to be an inflated total. The 1988-91 National Atlas showed Pembrokeshire contained Carrion Crows at maximum abundance and if their UK average density is adjusted to allow for this, suggests a county population of about 10,000 pairs, which seems realistic. The 2003-07 survey found no marked difference in distribution from the 1984-88 survey, so there has probably been no change in the size of the population.

Graham Rees

 

Fieldwork 2003-07 (based on 490 tetrads) 

Red = breeding confirmed = 354

Orange = breeding probable = 51

Yellow = breeding possible = 48

Total tetrads in which registered = 453 (92.4%)

Rook - 2003-07

The Rook looks similar to a Carrion Crow but has a stepped forehead, a pointed bill, a grey–white area of bare skin around the base of the bill and loose flank feathers giving it a “baggy trousers” appearance. The large nest built of sticks is placed in the crown of a tree and several nests are grouped close to each other so that a colony is formed.

There have been many small shifts in the sites of rookeries in the county but no great change in overall distribution. Note the “Possible breeding” category has been omitted when assessing distribution, as Rooks recorded feeding in fields do not give any indication of the origin of their rookery. Site relocations have mostly been due to tree felling but in some cases are for unknown reasons. No complete county rookery census has been conducted during the last 30 years. 

Based on the three previous censuses a county population of between 8,000 and 10,000 pairs was extant over a period of 31 years. The BBS has indicated a 15% decrease in Wales between 1994 and 2007. However limited local surveys conducted over a period of 15 years in the 1980’s and 1990’s, showed fluctuations in annual totals but stability overall. On the information available, it seems reasonable to conclude that there has been no marked change in the Pembrokeshire breeding population and that a countywide census is desirable.

Graham Rees

 

Fieldwork 2003-07 (based on 490 tetrads) 

Red = breeding confirmed = 211

Orange = breeding probable = 3

Total tetrads in which registered = 214 (43.7%)

Jackdaw - 2003-07

At the close of the survey of 1984-88 it was realized that the only assessment of breeding Jackdaw numbers anywhere in the county came from the islands of Skokholm and Skomer. An estimate of the population for the whole county had not previously been attempted. An assessment that an average of 20–30 pairs per tetrad was possible was used, postulating that there were 9,000–13,000 pairs breeding in Pembrokeshire. The 1988-91 National Atlas calculated an average density across the UK which was a little lower than the lowest value used for the initial local survey. The National Atlas also assessed relative abundance, the map of which showed Pembrokeshire at maximum. Making an adjustment to allow for this density suggests that the original estimate of 20 pairs per tetrad in the county was realistic. The BBS then indicated a 36%increase in Wales as whole between 1994 and 2007. No evidence was found that such an increase had taken place in Pembrokeshire but some sign that it has not.

Over the years there has been a 33% decline in the number breeding at Skokholm and a 66% decrease at Skomer. Studies on the islands have shown very low productivity even during times when breeding numbers increased there, meaning birds were being recruited from the mainland. The declining numbers which followed suggests such recruitment ceased, probably because there was no longer a surplus of birds on the mainland. With this in mind it seems best to be cautious and consider that county numbers had not increased. In this case the breeding population in Pembrokeshire at the end of 2007 was thought to have been about 9,000 pairs.

Graham Rees

 

Fieldwork 2003-07 (based on 490 tetrads) 

Red = breeding confirmed = 361

Orange = breeding probable = 18

Yellow = breeding possible = 58

Total tetrads in which registered = 437 (89.2%)

Magpie - 2003-07

A familiar bird to most people, the magpie can be encountered throughout the county and in most habitats. Its large stick nest, with its protective canopy, is obvious in the early spring before trees acquire their covering of leaves. 

The 1984-88 survey was accompanied by a population estimate of 22,000 pairs. As stated at the time, this was an extrapolation from a very small sample, and with the benefit of hindsight led to an inflated value. The 1988-91 National Atlas  showed that Magpies reached maximum abundance in Pembrokeshire, it also quoted densities of over 20 pairs per tetrad in farmland and 40 pairs per tetrad in woodland and suburban habitats. Applying these densities to the geography of Pembrokeshire and the distribution plotted by the 2003-07 survey, results in an estimated county total of about 10,000 breeding pairs.

Graham Rees

Fieldwork 2003-07 (based on 490 tetrads) 

Red = breeding confirmed = 305

Orange = breeding probable = 81

Yellow = breeding possible = 59

Total tetrads in which registered = 445 (90.8%)

Jay - 2003-07

The Jay is a medium-sized bird which is pinkish-brown in appearance, with blue and white wing patches, black tail and white rump. Despite its striking appearance, the Jay is shy and retiring and its presence is often first revealed by its raucous call. It is found in woodland and mature gardens, placing its nest close up to the trunks of trees or among thickets of ivy or thorns.

An estimate of 600 pairs breeding in Pembrokeshire was made at the close of the 1984-88 survey, based on an average density of three pairs per occupied tetrad. The 1988-91 National Atlas used an average density of four pairs per tetrad when calculating the UK total breeding population. The relative abundance map in that book indicates that this value might well have been applicable to Pembrokeshire. This would have elevated the county total to 800 pairs. The BBS charted a decrease of 14% across Wales between 1994 and 2007 and the survey of 2003-07 returned a 6% increase in distribution in the county. Applying the BBS value to the 2007 county distribution, results in an estimate of 730 pairs breeding in Pembrokeshire at the end of 2007.

Graham Rees

 

Fieldwork 2003-07 (based on 490 tetrads) 

Red = breeding confirmed = 31

Orange = breeding probable = 85

Yellow = breeding possible = 96

Total tetrads in which registered = 212 (43.3%)

Leach's Petrel - breeding season

Oceanodroma leucorhoa

Leach’s Petrels have been noted visiting Storm Petrel breeding colonies at Skokholm, occasionally singing, as follows: 15th July 1966, 22nd – 23rd June 1976, 1st June 1978, 21st May, 9th and 12th June 1980, 22 June 1989 and two birds were seen and heard regularly between the 1st June and 2nd July 1977.

Graham Rees

(Covers records up to and including 2011)

Leach's Petrel - 2012 winter

Leach’s Petrel Oceanodroma leucorhoa Winter

BWP notes that stragglers remain in the North Atlantic during winter which may explain December sightings of singles at Strumble Head on the 26th 1997, Newgale on the 24th 1989, Wiseman’s Bridge on the 24th and 25th 1989 and six in Angle Bay during December 1989. Additionally, in December 2006 a total of at least 240 were reported from Strumble Head, Newgale, Druidston and Freshwater West, 150 of them at the latter locality, and singles were found stranded in car parks at Cwm yr Eglwys and Haverfordwest.

There have been no January sightings but one was at Fowborough (Daugleddau) on the 6th February 1983, 14 at Goultrop Roads on the 3rd February 2002 and six at Strumble Head on the 6th February 2002, the 2002 records part of a larger incursion when 314 were noted off Aberaeron, in neighbouring Ceredigion on the 6th February. None have been recorded in March but three were seen off St Govan’s Head on the 4th April 1998.

Graham Rees

(Covers records up to and including 2011)

References

CRAMP. S. (Editor), 1977 – 1994. Handbook of the Birds of Europe, the Middle East and North Africa : the birds of the Western Palearctic, Oxford University Press, 9 Vols.

Leach's Petrel - autumn

Oceanodroma leucorhoa

Near annual passage migrant and occasional summer visitor.

Breeds around the North Atlantic and North Pacific, migrating south to winter in regions of tropical convergences.

“Not very rare as a visitor in stormy weather” wrote Mathew (1894), this based on his visiting various collections of stuffed birds and noting down information imparted by numerous sporting friends and taxidermists. This method evidently worked but with the demise of collecting specimens Lockley et al (1949) had no such network available to them, noting only one occurrence “in the last fifty years”, picked up at Pembroke Dock on the 12th November 1931.

A large scale “wreck” of Leach’s Petrels took place on the western seaboard of Britain and Ireland between the 21st October and the 8th November 1952. It was thought to have been caused by widespread gales and persistent strong winds over the North Atlantic during October. It is probable that the whole North Atlantic population of Leach’s Petrels was affected, not just the European component. Hence Canadian birds might well have been among the 88 dead and five alive found along a quarter of a mile stretch of Newgale beach on the 27th October, two dead at Dale before the 2nd November, three dead at Marloes before the 2nd November and “several” others there before the 4th November. (Boyd,1954).

Just six birds were recorded over the following 30 years, namely: one picked up in an exhausted condition at Broad Haven (N) on the 1st November 1954, which recovered and flew off; one at the Gann on the 19th October 1959; three seen from the Fishguard to Rosslare ferry on the 15th September 1966; one off Strumble Head on the 22nd September 1974.

There was an upsurge in the number of active observers from the early 1980’s. There was also a growing interest in seawatching and an improvement in the quality of optical equipment, which resulted in a better understanding of the status of the Leach’s Petrel in Pembrokeshire.

The main observer effort was made at Strumble Head, which proved to be well placed for witnessing autumn seabird movements. Leach’s Petrels were recorded in variable numbers in most autumns from 1983 onwards, the majority passing in September and October but also a few in August, one as early as the 3rd, and into November up to the 20th. Peak numbers were recorded when there were strong winds from the north-west or north. None were seen when there were winds with an easterly component. 

Day maxima counts were: 79 on the 13th September 1997, 85 on the 7th September 1990, 109 on the 13th September 1988, 81 on the 15th September 2001 followed by 122 the following day, and 120 on the 16th September 2010. 

Few have been recorded in autumn away from Strumble Head, they were singles at the Smalls on the 24th September 1983 and 20th September 2005, Fishguard Harbour on the 19th November 1990, from the Fishguard to Rosslare ferry on the 30th August 1995, Newport Bay on the 17th October 1998 and 23rd September 2004, Ramsey 11th September 1997 and Grassholm on the 18th September 2005, with three off St David’s Head on the 16th September 2001.

Graham Rees

(Covers records up to and including 2011)

References

BOYD. H. 1954. The “wreck” of Leach’s Petrels in the autumn of 1952, British Birds, Vol 47 : 137-163.

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.

Smew - 2011

Mergellus albellus

Scarce winter visitor.

The Smew breeds from Fenno–Scandia eastwards to central Siberia, a proportion of these wintering in the Baltic and North Sea countries, particularly Holland. The Smew has long been a regular winter visitor to southern England, with further influxes when winter conditions have frozen birds out of nearby mainland Europe.

It has occurred less regularly in Wales and in Pembrokeshire a total of 52 birds have been recorded in 25 years between 1904 and 2008. All records refer to single birds apart from two at Dale in 1904, two at Fernhill on the 23rd February 1985, two at Carew Mill Pond on the 1st January 1997, three at Dale on the 16th January 1963, up to four at Pembroke Mill Ponds between the 12th and 26th January 1997 and six at Orielton in January and February 1939, the latter referred to as eight in Donovan and Rees (1994) due to a typographical error.

The majority of Pembrokeshire records do not correlate with influxes to the UK caused by cold continental weather. Smews are restless and mobile birds and it is this characteristic which has probably resulted in most Pembrokeshire records. Such restlessness was demonstrated on a local scale in January to March of 1966, when one was frequently seen at both Bicton Reservoir and Marloes Mere but never at both localities during simultaneous observations.

Apart from the localities already mentioned, Smews were recorded at St Dogmael’s, the Teifi Marshes, near Newport, Fishguard Harbour/Goodwick, Heathfield Gravel Pit, near St David’s, Solva Harbour, Castle Pill, Landshipping, Llangwm, Hook, Little Milford, Bosherston, Llys y fran Reservoir and Rosebush Reservoir.

The earliest recorded in the county was near St David’s on the 10th October 1914, the latest at Llys y fran Reservoir on the 29th March 1992. 

Presence by month, 1904 – 2011.

Most records refer to one date only but Smews have stayed from up to ten days to three months. Only seven adult males were involved in the Pembrokeshire record.

Graham Rees.

(Covers records up to and including 2011).  

Bonaparte's Gull - vagrant

Larus philadelphia

Vagrant

The Bonaparte’s Gull breeds in W Alaska and across Canada, wintering along both the Pacific and Atlantic coasts. A few are recorded annually in the UK.   

The first Bonaparte’s Gull recorded in Pembrokeshire was shot at Solva in the spring of 1888 and taken into the bird collection of H.W.Evans. Although some of this collection went to the Tenby Museum the Bonaparte’s Gull was not included and consequently it has not been possible to establish whether it was an adult or not.

The second record was of a first winter bird seen in flat calm conditions at Strumble Head on the 28th September 1997, dip feeding across the whirlpools of the inner tide race in the company of a Common Gull and a Black-headed Gull.                

Graham Rees

Little Egret - visible migration

Egretta garzetta

Notable visible movements recorded were of one flying to the south, towards Devon, at Penally on the 1st May 1997, three flying eastwards towards the mainland at Skomer on the 4th September 2003, four flying north west towards Ireland at Strumble Head on the 24th August 2004, a single bird doing likewise there on the 27th August 2006, also two heading north east towards Ceredigion on the 9th August 2005, nine heading north west out to sea at St David’s Head on the 9th July 2009.

Graham Rees

(Covers records up to and including 2011)

Little Egret - breeding season

Egretta garzetta

In March 1995 five Little Egrets were noted displaying at a heronry and in 1996 two birds were seen sitting on nests, as was one in 2003. It is not known whether these breeding attempts were successful. Also in 2003 what was probably a fledgling was seen near another heronry, where two adults had been seen previously. A group of nine at Quoits Marsh on the 1st August 2008 were thought to be two family parties. A juvenile being fed by an adult at the Eastern Cleddau in June 2009 may have indicated breeding had taken place in the vicinity. Two or three occupied nests with young were noted at one Cleddau site in 2010.

Graham Rees

(Covers records up to and including 2011)