Wren - 1949 status

Troglodytes troglodytes troglodytes

Common resident, also breeding Caldey, Skomer, and Ramsey, but not Sokholm or Grassholm.  Ringed Wrens returned to winter on Skokholm.

R.M.Lockley, G.C.S.Ingram, H.M.Salmon, 1949, The Birds of Pembrokeshire, The West Wales Field Society

Wren - 2003-07

The estimate of 40,000 breeding pairs accompanying the 1984-88 survey was based on an estimated average density of 100 pairs per tetrad. The UK national average was assessed as being 120 pairs per tetrad. The lower estimated density in Pembrokeshire was based on the premise that the predominant pastureland would hold fewer birds than richer habitat to be found further east. However, subsequent findings have shown that density is high in areas of pasture, and the 1988-91 National Atlas, depicts maximum abundance in Pembrokeshire as a whole. It seems reasonably safe therefore to apply the UK value to the 2003-07 results, taking into account that the BBS indicates a 12% increase in Wales between 1994 and 2007. This results in an estimate of about 62,000 pairs breeding in the county. The population is expressed in pairs but Wrens are often polygamous, especially in prime habitat such as deciduous woodland.

Wrens can suffer high mortality during cold winters but there were unbroken mild winters during the years between the two local surveys, which would have been a major factor in the steady increase in their population.

Graham Rees

 

Fieldwork 2003-07 (based on 490 tetrads)

Red = breeding confirmed = 195

Orange = breeding probable = 265

Yellow = breeding possible = 7

Total tetrads in which registered = 467 (95.3%)

Wren - 1994

Breeding resident

A common resident to Mathew (1894) and Lockley et al. (1949). Today Wrens nest everywhere in Pembrokeshire apart from the mountain tops and the smallest offshore islets such as Grassholm and the Smalls (see map). At an estimated 100 pairs per tetrad the population probably totalled about 40,000 pairs during the 1984-1988 Breeding Birds Survey.

Wrens suffer high mortality during severe winters, that of 1963 being particularly devastating. Numbers recover quickly in subsequent breeding seasons provided no further cold winters intervene. Wrens are predominantly woodland birds in Pembroke­shire during times of low population, suggesting that this is their preferred habitat and that other places are occupied as increasing numbers enforce expansion; for instance, Skokholm was colonised for the first time in 1987 when the mainland population was high.

Fieldwork 1984-88 (based on 478 tetrads)

Red = breeding confirmed = 210

Orange = breeding probable = 230

Yellow = breeding possible = 8

Total tetrads in which registered = 448 (93.7%)

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

Wren - 1970s breeding

Red = breeding confirmed

Orange = breeding probable

Yellow = breeding possible

Wren - 1980s winter

The BTO winter atlas showed that Wrens were present in the majority of 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 25 birds seen in a day.

Graham Rees 

Wren - 1894

Species account from M Mathew, 1894, "The Birds of Pembrokeshire and its islands"

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