Little Grebe - 1994

Breeding resident and winter visitor

Mathew (1894) stated that the Little Grebe was a breeding species in Pembrokeshire but was more frequent in the winter months. Lockley et al. (1949) considered that it did not breed but was numerous in the winter. Saunders (1976) also regarded it as a non-breeder.

Lloyd proved breeding at Llambed in 1936 and suspected it at Slebech in 1937. Breeding was proved at Thornton in 1965, at Pembroke Mill Pond in 1975, at Trefloyne in 1981 and was suspected at Bosherston Pools during the 1970s and 1980s. The Dyfed Wildlife Trust Breeding Birds Survey of 1984-1988 discovered that about a dozen pairs of Little Grebes bred. The localities included Llambed where the grebes were particularly secretive and difficult to see, just as Lloyd noted in 1936, and it is tempting to think that they may have bred there throughout the intervening years.

The Little Grebe is more widespread and numerous in the winter months, when it can be found on estuaries and fresh waters, often occurring on quite small farm irrigation reservoirs. Up to five birds is normal at most localities but there are sometimes larger gatherings at favoured spots: up to seven in the Nevem Estuary, ten at Bosherston Pools, 13 at Carew/Cresswell, 32 at the Gann and in Hook Reach and 40 at Pembroke Mill Pond, the total winter population being about 150 birds. The numbers and pattern of occurrence noted by Lloyd (1925-1937) are consistent with that seen today, suggesting that Lockley et al. were interpreting a similar situation when they described this bird as "numerous".

Little Grebes have not been seen migrating during the day and it is presumed that the occasional occurrence of birds at Skokholm and Skomer and on the open sea off Strumble Head refer to grounded night migrants. 

 

Fieldwork 1984-88 (based on 478 tetrads)

Red = breeding confirmed = 6

Orange = breeding probable = 3

Yellow = breeding possible = 5

Total tetrads in which registered = 14 (2.9%)

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

Great Northern Diver - 1994

Winter visitor and passage migrant. Recorded in every month

Appears to have decreased since the 1940s as both Mathew (1894) and Lockley et al. (1949) stated it was sometimes numerous, particularly in Milford Haven. Dickenson and Howells (1962) noted groups of up to 20 and recorded mainly immature birds. Although 26 in a day have been seen passing Strumble Head during autumn passage, in winter there is a scattering of ones and twos around the outer coastline with occasional concentrations at favoured spots; for example, up to five have been seen in Fishguard Harbour, five in St Bride's Bay and seven in the Strumble Head tide races, with a remarkable 43 there on 6 January 1991, following prolonged gales. It is no longer numerous in the Cleddau Estuary. One or two still occur fairly regularly between Dale and Hakin, with up to five on occasions, but they rarely penetrate further up river. It is seldom seen on fresh water, with just a few records from Llysyfran reservoir and Bosherston Pools.

There is a small spring passage from March to May and a large autumn passage from September to December, birds in full summer plumage occurring particularly in May and September but sometimes in other months.

Black-throated Diver -1994

Scarce winter visitor and passage migrant. Recorded in all months except June, July and August.

Mathew (1894) classified the Black-throated Diver as a winter visitor on the strength of it being included in one of his correspondent's lists, whereas Lockley et al. (1949) considered it "almost as frequent as the Great Northern Diver in winter". Dickenson and Howells (1962) stated it "has always been, and still is, an uncommon bird" in Pembrokeshire, and Saunders (1976) classified it as "scarce" and the rarest of the divers. There has been an increase in the number of active observers in Pembrokeshire in recent decades with superior optical aids to those available in the past, revealing the Black-throated Diver to be a regular winter visitor and passage migrant in small numbers. It is probably still slightly under recorded, divers often being tantalisingly just too far away for certain identification. Nonetheless it has been recorded from all around the outer coast at one time or another, Fishguard Harbour, Strumble Head, St Bride's Bay and the Amroth—Saundersfoot area being the localities from which it is most often reported. Usually one or two birds are seen, occasionally three or four and perhaps a dozen are spread around the county coastline each winter. Has only been recorded inland at Llysyfran reservoir and is the only diver to have been recorded as far out to sea as the Smalls.

A few birds have been noted in full summer plumage, in the months of May, September and October.

Red-throated Diver - 1994

Winter visitor and passage migrant. Recorded in every month except June

Mathew (1894) classified the Red-throated Diver as "the commonest of the three divers that visit our bays and estuaries", and noted Fishguard Harbour and Milford Haven as being particularly good localities. Lockley et al. (1949) also considered it a common visitor, especially to Milford Haven but also "frequent at sea near coasts and islands". Lockley (1961) stated that the Red-throated Diver was more frequently seen than other species of diver. The diaries of Bertram Lloyd for 1925-1937 enable us to compare the statements above with the current situation and his record is consistent with modern findings, so it is probable that the status of the Red-throated Diver has not changed for at least the last 60 years or so. It remains the commonest of the diver species occurring in Pembrokeshire, but is no longer frequent in the Cleddau Estuary (the Milford Haven of Mathew and Lockley et al.) where now only one or two appear, sporadically and mostly at the seaward end.

Red-throated Divers can be found all around the outer coastline in winter. Usually only one to three birds are seen at each locality but they occasionally congregate at favoured tide-races or bays, especially following onshore gales, when up to 18 have been seen off Giltar, 20 in St Bride's Bay, 23 in the Amroth—Saundersfoot area and 40 off Strumble Head. However an exceptional gathering of 200 was at Amroth in late February and early March 1993. Singles at Llysyfran reservoir and Bicton and Hayston Hall farm irrigation reservoirs are the only records from inland waters.

There is a small northerly passage from March to May, when many are in transitional, occasionally in full, summer plumage. The autumn passage south, from September to December (exceptionally from July and August) is of greater volume. Birds in full summer plumage predominate until mid-October, indicating that most juveniles arrive later, though an adult was seen feeding two accompanying juveniles at the Gann on 27 September 1969.

Great Black-backed Gull - 1994

Breeding resident

George Montague (1866) found none breeding in Pembrokeshire while Mathew (1894) knew of only a few pairs resident on some of the islands.  By 1949 Lockley et al were able to note that great black-backed gulls could be found breeding along the whole coast, with a total of 310 pairs on the islands of Grassholm, Skomer, Skokholm, Middleholm and St Margarets, and with others on Ramsey, the Bishops and along the mainland coast.  Davis (1958) during his survey of this species in England and Wales, reported between 490 and 520 pairs in Pembrokeshire.  The population continued to increase; for instance there were 60 pairs on Skomer in 1949 but this had risen to 283 pairs by 1961.  Control measures were applied at Skokholm and Skomer from 1958 to reduce their predatory effects on other seabirds.  This halted and then reversed the increase, and the Skomer population was down to 165 pairs by 1969. At this time Operation Seafarer found a total of 542 pairs breeding in Pembrokeshire, and it is thought that the population may have stabilised at this level.

Great black-back gulls are largely coastal birds, although they find inland rubbish tips readily enough.  A proportion disperse during the winter, some reaching the upper Bristol Channel, with first year birds moving to Cornwall and Ireland; and a Fair Isle-ringed bird has reached Skomer.  A county total of 300 found during the BTO winter gull survey of 1983 suggested that the bulk of the population may stay in Pembrokeshire.

Fieldwork 1984-88 (based on 478 tetrads)

Red = breeding confirmed = 25

Orange = breeding probable = 5

Total tetrads in which registered = 30 (6.3%) 

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

Herring Gull - 1994

Breeding resident and winter visitor

Mathew (1894) commented on an increase in the number of breeding herring gulls in the wake of the sea birds preservation act of 1869.  Lockley et al (1949) traced a continued increase, despite large scale collection of gulls eggs; for example, about 3000 eggs were taken in one season at Skokholm, from a colony of 1000 pairs. 

Limitations were put upon the collection of eggs at Skokholm and Skomer and the harvesting of eggs generally declined throughout the county as social conditions changed.  Herring gulls accelerated their rate of increase, a process aided by the abundance of food at local refuse dumps.  In 1969 Operation Seafarer recorded 11740 pairs breeding in Pembrokeshire, including 1350 pairs on Skokholm and 2200 pairs at Skomer.  Most nest on the cliffs of the mainland and islands but roof nesting has been noted at Tenby and the Esso refinery at Herbrandston and suspected elsewhere.

Herring Gulls began to decrease in the lat 1970s, coinciding with the introduction of black plastic bags for refuse collection.  In warm conditions these bags make good incubators for the bacterium Clostridium botulinum which is thought to have poisoned the gulls feeding on the rubbish tips.  By the time the Seabird register survey of 1985-87 was conducted the breeding population had shrunk to 4062 pairs, with 613 pairs at Skomer, and 321 at Skokholm.  Changes in rubbish tip operations are coming into force which will make harmful food less accessible to gulls, and this may reverse the decline.

Herring gulls are not confined to scavenging on rubbish tips, but feed widely across the fields of the county, where earthworms form an important part of their diet.  They also feed around the rocky shores and the estuaries and pick up fish offal at Milford Docks, though fewer catches are landed there than in the past.

Although generally regarded as sedentary, many of our herring gulls disperse from the breeding grounds in the winter, certainly as far as the upper Bristol Channel.  Juveniles can venture further, with recoveries from North Wales, Ireland, France, Holland and Poland, as well as of an Irish-bred bird visiting Pembrokeshire.

Small numbers of Scandinavian birds of the subspecies argentatus were detected in the winters of 1985 to 1987, with records occurring between 11 December and 22 February.

Fieldwork 1984-88 (based on 478 tetrads)

Red = breeding confirmed = 63

Orange = breeding probable = 3

Total tetrads in which registered = 66 (13.8%)

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

Lesser Black-backed Gull - 1994

Breeding summer visitor, passage migrant, winter visitor

Mathew (1894) knew of colonies of 20-30 pairs which Lockley et al (1949) used as a datum to note a considerable subsequent increase in breeding numbers with 1000 pairs at Skomer and 800 pairs at Skokholm; they added that they bred at Caldey, St Margaret’s, Ramsey, Sheep Island and some mainland cliffs such as those at Pwll Deri.

Lesser Black-backed Gulls continued to increase and the Skomer colony had reached 3657 pairs by 1970 with 2500 at Skokholm.  During this period Harris (1965) noted that they predominantly foraged on the agricultural mainland and mainly ate beetles.  The population increased rapidly thereafter and numbered about 20,300 pairs by 1983, with 15500 at Skomer and 4557 at Skokholm.  Studies showed that about 80% of their food consisted of small fish, mostly young blue whiting and poor cod (Todd 1986).  Although birds continued to frequent agricultural land, and a few visited rubbish tips, the greatest proportion flew out to sea to the south-west to feed upon fish discards from the trawlers in the southern Celtic Deep, as far away as 80-100km.  There has been a reduction in numbers since then, the Seabird Register survey of 1985-1987 finding 16560 pairs.  Census results from Skomer illustrate how the population has changed.

The colonies at Skokholm and SKomer experienced large scale breeding failure in 1989 and 1990, and low productivity in 1991 and 1992, with eggs hatching but few young being reared.  A shortage of fish seems to have been the cause, due to changes in fishing practice.  The bulk of the population have now switched to foraging in mainland fields, and studies at the colonies show that they are bringing back insufficient food.  They are also spending long periods away from the nest, which has led to increased predation of eggs and young by other adults.  If fish remains unobtainable the population may dwindle to a level that can be sustained by food gleaned from agricultural sources.  They visit all parts of Pembrokeshire to feed in the pastures, being particularly attracted to fields where slurry is being sprayed, which are being ploughed or which have just been cut for silage.

Most lesser black-backed gulls nest on the plateaux and slopes of the islands, with comparatively few on the cliffs, but a few use the roofs of buildings at the old Esso oil refinery at Herbrandston.  Roof nesting was suspected in the past at Kensington hospital (St Bride’s) and at the former county cinema in Haverfordwest.

Many leave Pembrokeshire after breeding, ringing showing that they can reach Spain and Portugal by October, some penetrating to Morocco and the Canary islands during the course of the winter.  Others pass through Pembrokeshire on spring and autumn passage.  The bulk of the breeding birds return during March.

Rather few lesser black-backed gulls used to winter in Pembrokeshire, with 10-13 seen in 1937 (Lloyd’s diaries) and usually less than ten in a winter during the 1950s.  Winter numbers had increased to about 1500 by 1971 and to 7000 by 1987, most roosting at Llysyfran reservoir.  Whether these are local birds in unclear.

In most winters up to five birds of the Scandinavian races are identified between 16 November and 22 March, the majority seeming to fit the description of subspecies intermedius, which have darker mantles than the British race.  A group of 30 of this subspecies seen at the Gann on 18 January 1987 was accompanied by a very convincing black-backed subspecies fuscus.

Fieldwork 1984-88 (based on 478 tetrads)

Red = breeding confirmed = 24

Orange = breeding probable = 1

Total tetrads in which registered = 25 (5.2%)

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

Update on Saturday, August 3, 2013 at 10:28AM by Pembrokeshire Avifauna committee

The means of field identification of the different races of LBbGs has developed beyond the assessment of the shades of the upperparts, prevalent during the 1990s. It would seem prudent therefore to discard past racial identifications in favour of more rigorous examination of future occurrences.

Graham Rees

Common Gull - 1994

Winter visitor

Both Mathew (1894) and Lockley et al (1949) described the Common Gull as a frequent autumn and winter visitor, a status which has not changed.

The birds begin to arrive from early August onwards, and are mostly adults, sometimes accompanied by birds of the year.  The main winter population arrives in October, recoveries suggesting a northern European origin.  For instance, one ringed in north Germany in July 1953 was recovered at Lamphey in February 1956 and another ringed at Skokholm in February 1956 was recovered in Norway in June 1957.  Small numbers frequent the outer coastline and the estuaries but most forage widely across inland fields, commuting from the main roosts at Fishguard harbour, Cleddau Estuary and Amroth-Saundersfoot, with an average count total of about 4000 birds.  Most depart during March with a few others passing through in April and May, while first year birds occasionally summer at the coast.

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

Redshank - 1994

Winter visitor and passage migrant, has bred in the past

Mathew (1894) knew of no definite breeding records for redshank. It was suspected that redshanks bred near St David’s in 1932 and 1948 (Lockley et al 1949) while two pairs definitely bred at Trefeiddan, also near St David's, in 1955.  There have been no breeding records since.

Mathew (1894) noted that although previously common, the redshank had markedly decreased including in the Cleddau Estuary where Lockley et al (1949) had noted it as an abundant winter visitor. Lloyd’s diaries for 1925-37 contain dates, counts and localities that suggest that its status then was similar to today.  The Cleddau Estuary counts demonstrate the general pattern of occurrence and the numbers involved.

Up to 30 redshanks winter on the Teifi Estuary. Three to five in Fishguard Harbour and 10-15 in the Nevern Estuary.

They arrive from 11 June, numbers building up progressively to peak in December before levelling out to a settled winter population.  Departure takes place in late March and early april with only small numbers staying until late May.  Redshanks also pass through Pembrokeshire on passage between March and May and between June and November, when they are seen at headlands and offshore islands, are heard passing at night and have been recorded at lighthouse attractions at Stumble Head.  Groups have been seen to depart northwards from the Cleddau Estuary on calm spring evenings.

Rees G H & Donovan J W, 1994, Birds of Pembrokeshire, Dyfed Wildlife Trust

Curlew - 1994

Breeding resident, winter visitor and passage migrant

According to Mathew (1894) curlews bred on the Preseli Mountains and occasionally on Skomer.  Lockley et al (1949) stated that they were not common as a breeding bird before the early 1930s, but greatly increased afterwards to breed throughout the county, including Ramsey and Skomer but not the Castle Martin peninsula, being most numerous in the north.  Lloyd’s diaries indicate that they were a widespread breeding species in Pembrokeshire by 1927.  The breeding range extended to the Castle Martin peninsula in about 1950 (Lockley 1961)

Extensive land reclamation and drainage was to follow, while traditional grazing of common land decreased, modifying the tussocky structure and permitting invasion by scrub.  The curlew’s breeding range retracted and Saunders (1976) found them nesting in only small numbers.  The decline continued, curlews last occupying breeding grounds at Rosebush in 1980, Slade Bottom near Puncheston and Dowrog common in 1983.  The Breeding Birds Survey of 1984-1988 found only about 20 pairs, 13 on Skomer and the rest on bogs in the Preseli Mountains, although they were also present in the breeding season in the meadows around the junctions of the rivers Syfynwy and Easter Cleddau.

They are much more widespread outside the breeding season.  A few non-breeders are present in late May and early June, numbers building up quickly during July and peaking in September before settling back to the winter level.  A rapid departure takes place in March and early April,  Numbers reach 600 on the Teifi estuary, up to 450 on the Nevern estuary, and 100 in Fishguard Harbour, but they are not confined to estuaries, being found also on beaches and field all around the coastline, as well as on the offshore islands.  The average total mid-winter population is probably about 3000 birds.

They migrate by day as well as by night, being seen flying in off the sea along the snorth coast and down the west coast in autumn, and arriving from the south of the southern shores in the spring.  They are not infrequently heard passing over the county at night, and have been noted at lighthouse attractions at the Smalls and Strumble Head. 

Ringing has shown that curlews from northern Britain and Finland visit Pembrokeshire.

Fieldwork 1984-88 (based on 478 tetrads)

Red = breeding confirmed = 2

Orange = breeding probable = 6

Yellow = breeding possible = 4

Total tetrads in which registered = 12 (2.5%)

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

Teal - 1994 Birds of Pembrokeshire

Common winter visitor, passage migrant and scarce breeder

The status of the Teal has probably changed very little from that recorded by both Mathew (1894) and Lockley et al (1949).

It has bred in a variety of localities over the years, but has probably not nested annually.

It is common throughout the winter, when small groups are distributed widely at farm irrigation reservoirs and waters such as Bosherston Pools and Pembroke Mill Pond.  There are usually concentrations of 200 or more on the Pentood Marshes and 300 or more at Marloes Mere but the main concentration is found on the Cleddau Estuary, particularly upstream from Daucleddau.  They arrive from July, slowly building up to peak numbers in December and January, then depleting slowly through February with a sudden exodus from late March to early April.  The average Cleddau Estuary peak count for 1983-87 was 2028 and for 1988-92 was 2425.

Extensive ringing conducted at Orielton from 1937 to 1961 has shown that many of the Teal that occur in Pembrokeshire in the winter later breed on the Western Siberian Plain, extending as far as 61 degrees each beyond the Pechora River.  They pass down through the Baltic area and, having arrived in Pembrokeshire, stay for the winter, but others travel west to Ireland or southwards to France, Portugal and Spain, while yet others spread north and east across Wales, and into south England.

Males of the American race A c carolinensis were noted at Rosehill Marsh on 30^th January 1972 and at the Gann on 22-27 April 1977 and 2 March 1986.

Fieldwork 1984-88 (based on 478 tetrads)

Red = breeding confirmed = 1

Yellow = breeding possible = 1

Total tetrads in which registered = 2 (0.4%)

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

Wigeon - 1994 Birds of Pembrokeshire

Winter visitor and passage migrant.  Not recorded in July

Past evidence suggests that the wigeon may well have been more numerous than it is now.  At the Orielton Decoy 500-600 were taken annually during the winters of the 1870s and 1880s, suggesting that a very large population must have been present.  Mackworth Praed (1946) thought that probably 9,000-10,000 was the daily presence at Orielton prior to the 1930s, but in that decade numbers dwindled to about 3000 on the nearby estuary.  Lloyd noted about 3000 at Angle Bay in 1925.  A continued slow decline seems indicated by records of 2500 in the Hook area in 1949 and 1950, and about 2200 in Angle Bay in 1974.  The average of the peak counts for the whole of the Cleddau Estuary from 1983 to 1986 was 2060, and from 1988 to 1992 was 2331.

The picture changes when severe cold weather grips wintering areas further east, as it did in January 1987.  Suddenly about 10,000 wigeon appeared on or near the Cleddau Estuary with a further 3000 elsewhere, demonstrating how important the preservation of estuarine habitat in the mild west is.

Away from the Cleddau the wigeon is normally concentrated only at Marloes Mere (100-500 birds) and the Pentood Marshes (200-500 birds), with smaller groups using ponds and farm irrigation reservoirs.  These inland waters also provide a refuge during cold spells, as in 1987 when there were 1,000 at Treleddin Farm reservoir, 860 at Llysyfran reservoir, about 500 at Maerdy and about 500 at Bosherston Pools.

Wigeon arrive in Pembrokeshire from September to December.  Numbers peak in January, with a rapid departure in late March and stragglers occurring thereafter.  Small parties are seen passing Strumble Head and stopping off at the offshore islands during the arrival period but the bulk arrive unseen, presumably during the night.  Little visible movement is seen during the rapid spring departures.

Recoveries of Wigeon ringed at Orielton from 1937 to 1961 show that many of our winter birds breed on the western Siberian Plain, as far as 65 degrees east.  The recovery pattern also shows that they move down through the Baltic region after breeding, and that some of the birds that stop off in Pembrokeshire later carry on to Ireland.  Some return in subsequent winters but other range widely in France, Portugal, Spain and Italy.

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