Lesser Whitethroat - 2003-07
Friday, June 29, 2012 at 6:08PM The Lesser Whitethroat, a summer visitor, is an inconspicuous warbler which favours deep cover. Its most notable feature when seen well is its black patch through the eye. Its monotone rattling song often reveals its presence in the scrubby areas it frequents and where it nests.
No way has been found to separate possible passage birds from the records when evaluating the results of the 1984-88 survey. A minimal density of one pair per tetrad was used to estimate a county breeding population of 70 pairs. The 1988-91 National Atlas shows an abundance distribution where the Pembrokeshire density was much lower than the UK average of just over two per tetrad, suggesting that the local estimate was realistic. The same situation existed when assessing the returns from the 2003-07 survey, so the county estimate remains the same. Nonetheless the uncertainty of the impact of migrants being involved, means it should be regarded as a maximum and the true level might have been smaller, for the BTO considered that the UK population dropped to about 64,000 pairs by the year 2000 from an estimated 80,000 in 1991.
Graham Rees
Fieldwork 2003-07 (based on 490 tetrads)
Red = breeding confirmed = 4
Orange = breeding probable = 66
Yellow = breeding possible = 9
Total tetrads in which registered = 79 (16.1%)
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