Corvus monedula – JAC Y DO – Breeding resident
|No of tetrads occupied||449 (of 478)|
|Percentage of tetrads||93.9%|
A common resident according to Mathew (1894) and Lockley et al (1949), the Jackdaw is probably the most versatile of Pembrokeshire’s birds, for it has learnt to exploit just about every niche in the county, nesting in quarries, on crags, in trees, in buildings and other man-made structures, in the sea cliffs of the mainland and on the larger offshore islands.
They were noted breeding in burrows at Skomer as early as 1860 (Lockley et al.). Wintle (1924) recorded them nesting in fair numbers on Caldey in 1924 and Lloyd found that they were an established breeding bird on Ramsey in 1927. Skokholm was colonised in 1965, with numbers building to a peak of 60 pairs between 1975 and 1978 but declining to only five pairs by 1992. At Skomer they increased from 20 pairs between 1946 and 1958 to 200-250 pairs in 1961, and the 1991 census fround 248 pairs. Colony size elsewhere varies widely, but an estimated average density of 20-30 pairs per tetrad would mean a total breeding population of 9,000-13,000 pairs.
They form large communal roosts outside the breeding season, that at St David’s Cathedral being notable for creating so much noise during their evening assembly that it eclipses the best efforts of the choir!
Despite numerous records of Jackdaws flying about over the sea we have found no evidence to confirm immigration of emigration.
McCANCH, N. 1985. A lighthouse notebook. London, Michael Joseph.
WINTLE, W.J. 1924. Some Caldey birds Pax 71:133-139