Friday, August 23, 2013 at 7:56AM Riparia riparia riparia
Summer resident and passage migrant. Colonies, usually small, in river banks and gravel pits.
R.M.Lockley, G.C.S.Ingram, H.M.Salmon, 1949, The Birds of Pembrokeshire, The West Wales Field Society
Thursday, May 10, 2012 at 9:04PM Trans-Saharan migrants, Sand Martins usually arrive in Pembrokeshire in March, but were recorded as early as the 14th February during the 2003-07 Atlas survey period.
In Pembrokeshire, Sand Martins nest in sandy/gravelly river banks, in soft sandy/gravelly sea cliffs and in artificially created habitats, notably sand and gravel pits. They are highly colonial, and return to the same colony site, although they generally dig fresh nesting burrows, to avoid parasitic infestation. Sand Martins feed mostly on aerial insects, foraging over freshwater, wetlands and pasture, preferably grazed by cattle. They generally avoid urban and densely /wooded areas.
As illustrated by the map, on the mainland colonies are scattered on the coast and inland. With the exception of a cliff site in the Freshwater West area, all the colony sites were found in mid and north Pembrokeshire. Sand Martins are absent from the offshore islands.
At first glance, a comparison between the two tetrad surveys suggests a significant expansion in the breeding population of Sand Martins. A closer inspection of both the numbers of tetrads where Sand Martins were recorded and the tetrad map, however, revealed a 10% decrease in the number of tetrads where breeding was confirmed. There were also changes in distribution of colonies: They have disappeared from four tetrads in between the two surveys. This was counter-balanced by the recording of several new colonies, mostly on the coast.
The two sets of tetrad data for “confirmed” and “probable” breeding are very similar, although the tetrad map clearly suggests changes in distribution of colony sites. This could well indicate that suitable nesting habitat is a finite resource in Pembrokeshire, hence a potential limiting factor on the distribution and size of future breeding colonies of Sand Martins.
Sand Martin colonies tend to be transient, and will move if a particular sandy bank becomes over-stabilised. On rivers, fresh bank falls that occur whilst rivers are in spate will be preferred to stable bank/cliff faces that may become over-gown. Similarly, artificial sites e. g. sand and gravel pits will also be deserted once exposed faces become too stable, hence unsuitable for Sand Martins, they even move around within active sand pits. This is likely to be a contributing factor in the changes in distribution noted between the two surveys: sites may have fallen into disuse because they no longer offer suitable exposed, soft sandy/gravelly cliffs which birds can burrow into, yet are firm enough for the burrows to remain intact during the breeding season.
The overall size of the breeding population is not thought to have changed significantly between the two tetrad surveys, and is thought to be between 70 and 100 pairs ( the population estimate given in Donovan and Rees (1994) was based on accurate colony counts).
Jane Hodges
Fieldwork 2003-07 (based on 490 tetrads)
Large dots = breeding confirmed = 11
Medium dots = breeding probable = 2
Total tetrads in which registered = 13 (2.7%)
Friday, December 23, 2011 at 9:42AM Breeding summer visitor and passage migrant. Not recorded in January and December
A common summer visitor to Mathew (1894) "nesting in banks, the sides of gravel pits and old quarries". Lockley et al. (1949) noted the Sand Martin as a summer visitor to small colonies in river banks and gravel pits and as a passage migrant. Colonies in Pembrokeshire today are found in river banks, such as the Western Cleddau, sand pits such as Dale and Gupton, quarries including Treffgame and sea cliffs such as Abermawr. The occupation of sites varies according to the availability of suitably exposed sandy faces. River bank colonies are prone to move, so as to occupy the bends where there has been a fresh bank fall caused by spate during the previous winter. Sites that were occupied in the past, such as Dale sand pit, have become disused as they have become unsuitable. Some sites are only used for second broods, such as the sand pit at Trecwn. The Breeding Birds Survey of 1984-1988 found a total of 72 pairs breeding in Pembrokeshire (see map).
The first Sand Martins generally arrive in Pembrokeshire in the last week of March, but in some years they can be as early as 10 March, and one was at Bosherston Pools on 23 February 1989. Passage continues throughout April and May, sometimes until mid-June. Most pass through coastal areas and the offshore islands. They can be seen coming in off the sea along the southern shores, coasting along the western seaboard and departing out to sea from the north coast. They frequently stop off to feed on the way, especially over fresh water, including Pembroke Mill Ponds, Marloes Mere and Trefeiddan where aggregations of up to 200 occur. The Sand Martin population crash of 1983-1984 (Mead 1984) resulted in far fewer than normal passing through in the springs of those years, but there has been a steady revival in numbers since.
They begin to pass southwards on a broad front from July and continue until mid-September, numbers being smaller than in spring with usually less than 100 at any locality. Stragglers continuing up to 26 October are not rare, and one was seen at Bosherston Pools on 4 November 1986.
Fieldwork 1984-88 (based on 478 tetrads)
Red = breeding confirmed = 9
Orange = breeding probable = 1
Total tetrads in which registered = 10 (2.1%)
Sunday, November 13, 2011 at 2:55PM 
Red = breeding confirmed
Orange = breeding probable
Yellow = breeding possible
Saturday, December 18, 2010 at 8:58AM Species account from M Mathew, 1894, "The Birds of Pembrokeshire and its islands"
