Blackbird - 1980s winter

GHR

The BTO winter atlas showed that Blackbirds were present in all 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 115 birds recorded per day.

Ring recoveries confirm that the large winter presence includes Continental birds.

Black Redstart - 1980s winter

The BTO winter atlas shows the 10km squares where Black Redstarts were recorded 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 3 birds seen in a day.

Mainly recorded around buildings.

GHR 

Bittern - 1980s winter

The darkest colour on the map for the BTO winter atlas of 1981-82, 1982-82 and 1983-84 represents 3 or more birds in a day. In Pembrokeshire 4 at Bosherston was the maximum.

GHR

Bewick Swan - 1980s winter

The BTO winter atlas showed that Bewick’s Swans were present in seven10km 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 9-29 birds, the maximum in Pembrokeshire during the period being ten in 1981 during a cold weather influx.

GHR 

Bar-tailed Godwit - 1980s winter

 The BTO winter atlas showed that Bar-tailed Godwits were present in a few coastal and estuarine 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 19-175 birds, with the highest count being in SM 80.

The distribution is consistent with the Birds of the Estuary Enquiry (BoEE, now WeBS) at that time, with the majority of birds in Angle Bay, part of the Cleddau Estuary complex. .

The Nevern and Teifi estuaries provided winter records in the north of the county.

GHR 

Barnacle Goose - 1980s winter

Up to three birds were recorded in one 10 Km square during the 1981 – 1984 Winter Atlas.

The National Nature Reserve of Skomer was managed by a Warden from March to October during the Atlas years but not in the winter, when only occasional visits were made. These few visits indicated that up to 39 Barnacle Geese over wintered on the island but this information was not made available to the Winter Atlas, so is not represented on the map. 

GHR

http://blx1.bto.org/atlases/BY-atlas.html

Barn Owl - 1980s winter

The Winter Atlas showed that Barn Owls were recorded in 14 out of 27 of the county’s 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 3 birds recorded in a day.

This species can be difficult to detect in the winter when it is mainly nocturnal and silent, which despite being a resident, has resulted in a 40% lower registration than in the 1970 breeding atlas survey.

LACK, P.C. (1986) The atlas of wintering birds in Britain and Ireland. T. & A.D. Poyser

Little Grebe - Sea Empress oil spill

Tachybaptus ruficollis  

When the oil – spill caused by the grounding of the Sea Empress occurred, 15th – 21st February 1996, the Milford Haven waterway was badly contaminated, most heavily as far upstream as the Cleddau Bridge. Little Grebes quickly left this area, moving to safer places, notably to Westfield Pill where their presence rose from 39 to 52 birds. None were recorded dead or visibly oiled, so their rapid evasive action was evidently effective.

Graham Rees

(Covers records up to and including 2008)

References

HAYCOCK. A. 2008. A review of the status of wetland birds in the Milford Haven Waterway and Daugleddau Estuary, A report to the Milford Haven Waterway Environmental Surveillance Group. Unpublished

Little Grebe - Migration

Tachybaptus ruficollis

The Migration Atlas (2002) suggests that most Little Grebes disperse from their breeding area to winter elsewhere. It also states that there are still many unknowns about their migration, citing very few examples of immigration based on ring recoveries. BWP considered autumn and spring records on or near the British east coasts, especially at lighthouses, indicated immigration from the Continent.

There are no records of Little Grebes visibly migrating in Pembrokeshire, possibly meaning they pass at night but there have been none noted at local lighthouses. Diurnal records of birds on the sea at Strumble Head and Skomer and visiting ponds on Skokholm, Ramsey and most frequently Skomer, indicate dispersal at least and possibly longer distance migration as well.

Graham Rees

(Covers records up to and including 2008)

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.

Little Grebe - winter

 Tachybaptus ruficollis

Outside of the breeding season Little Grebes have been recorded on all of the estuaries and main freshwaters, as well as on many small ponds.

The Little Grebe was originally classified as a winter visitor by Lockley et al (1949) and Saunders (1976) when there were no known breeding birds in the county and they noted them on small ponds, lakes, reservoirs and estuarine arms. Only Saunders put any numbers to these occurrences, citing up to 20 on the Gann lagoon and 32 in Hook Reach.

Largest concentrations recorded between 1983 and 2005 were: Cleddau Estuary 69, Nevern Estuary 9, Teifi Estuary 8, Freshwaters 97.

Donovan and Rees (1994) estimated the average county winter population to be about 150 birds. Within the cover achieved by the Wetland Birds Survey team over 100 are on record for most recent winters, the maximum being 162 in the winter of 1996/97. However the survey could not cover all the small waters on which Little Grebes have been seen but seldom reported, so the 150 estimate on average is probably realistic or possibly a slight under estimate.

 Haycock (2008) noted a decline in Cleddau Estuary numbers from about the 1990’s and suggested this could be due to Westfield Pill becoming less suitable for this species. She also pointed out that the mid- winter population for the whole county was reasonably steady overall.

Normally they have started to appear on the estuaries in August and September and reached peak numbers by November to January, thereafter numbers diminished with most having departed by April.

Graham Rees

(Covers records up to and including 2008)

References

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

HAYCOCK. A. 2008. A review of the status of wetland birds in the Milford Haven Waterway and Daugleddau Estuary, A report to the Milford Haven Waterway Environmental Surveillance Group. Unpublished.

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

SAUNDERS. D. R. 1976. A brief guide to the birds of Pembrokeshire, Five Arches Press.

Little Grebe - breeding

 Tachybaptus ruficollis

Breeding resident and winter visitor.

The Little Grebe breeds throughout the temperate and tropical Old World and is resident, dispersive and migratory.

In Pembrokeshire it inhabits still fresh waters in the breeding season so is absent from the fast flowing rivers and streams. It requires waters to be vegetated around the fringes and beneath the surface. It is secretive and inconspicuous around the breeding area and can easily be overlooked, its far carrying, distinctive, whinnying call often being the first indication of its presence.

The breeding status of this species in the county in the past is difficult to evaluate. To Mathew (1894) it was a breeding species but by 1949 Lockley et al stated “apparently does not breed”.

Saunders (1976) commented “Strangely it does not remain to breed, for at least to human eyes, there are several suitable waters.”

However, Bertram Lloyd’s diaries contain records of breeding at Llambed in 1936 and suspected breeding at Slebech in 1937 and Sharrock (1976) indicated possible breeding between 1968 and 1972 in the south west of the county.

Donovan and Rees (1994) quoted breeding at Thornton Reservoir (now defunct) in 1965, at Pembroke Mill Pond in 1975 and at Trefloyne in 1981, with suspected breeding at Bosherston during the 1970’s and 1980’s.

The lack of breeding during the review periods of Lockley et al and Saunders might well have been the result of severe winters in 1939-40, 1947-48 and 1962-63 eliminating a small population which was previously present.

Two breeding bird surveys of the county using a grid of tetrads have since been completed and the results are summarised as follows: 

[Breeding maps & statistics]

Comparison of the results of the two surveys indicates an almost fourfold increase in the number of occupied tetrads during the elapsed period. Most birds were on well vegetated farm ponds used for irrigation. Many of the ponds used in 2003 – 07 had only recently been constructed in the 1980’s and only subsequently became vegetated and thus suitable for Little Grebes.

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

Graham Rees

(Covers records up to and including 2008)

References

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

LLOYD. B. 1929-1939 Diaries, National Museum of Wales.

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.

SAUNDERS. D. R. 1976. A brief guide to the birds of Pembrokeshire, Five Arches Press.

SHARROCK. J.T. R. 1976. The atlas of breeding birds in Britain and Ireland, Berkhamsted, T. & A. D. Poyser.

Carrion Crow - 2010

Corvus corone

Breeding resident.

The Carrion Crow was assessed as common and widespread in Pembrokeshire by Mathew (1894), Lockley et al (1949) and Donovan and Rees (1994). They were persecuted by gamekeepers during Mathew’s time, a hint of the scale being the record of 134 killed on the Cawdor estate in 1821. This continued into the Lockley et al era, an example being 150 counted on a gibbet at Slebech in 1930. Such carnage diminished during the two World Wars when many gamekeepers were recruited to the armed services. Control measures are still attempted but on a small and localised scale, so they are now unmolested over much of their county range.   

Nesting in trees, on old buildings and cliff ledges, the Carrion Crow has been found breeding all over the county, including the major offshore islands. Its breeding distribution was plotted in 1984 – 88 by a survey using tetrads as a grid and this was repeated in 2003 – 07.

Breeding surveys	1984 – 88	2003 – 07
Total tetrads where found	459	453
Confirmed breeding	390	354
Probable breeding	22	51
Possible breeding	47	48

An estimate of the breeding population was attempted following the survey of 1984 – 88, which 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 BTO’s New Atlas of 1988 – 91 showed Pembrokeshire contained Carrion Crows at maximum abundance and if their UK average density is used as an adjustment, a county population of about 10,000 pairs results, which seems more realistic. The 2003 – 07 survey found no marked difference in distribution from the 1984 – 88 survey, so there was probably no change in the size of the breeding population.

Being a successful breeder the Carrion Crow produces a surplus component to its population, comprised of immature birds that are too young to breed or adults which cannot find a vacant breeding territory. In places these form flocks which have been most noticeable on parts of the estuaries such as Fowborough and the Gann. This “reservoir” enables territories made vacant by various means, like shooting, to be recolonised.

There are several records of Carrion Crows flying in off or out to sea at headlands and islands, as far out as The Smalls, but the only concrete evidence of migration was of a nestling ringed on Bardsey Island which was recovered in north Pembrokeshire. 

Graham Rees.

(Covers records up to and including 2010)