Worcestershire Record No. 22 April 2007 p. 10

P. F. Whitehead

An unusual bird song noted at Beckford, Worcestershire (VC33 SO93) on 24 April 2007 proved difficult to identify. The bird was clearly defending territory in a small area of open, young, planted, ash-cherry woodland, with large wide sunny clearings and large scattered clumps of Blackberry Rubus fruticosus s.l..

The song was insistent and strident containing especially strong, voluble, repetitive notes of Song Thrush Turdus ericetorum Turton, 1796, but also deep throaty notes comparable to Nightingale Luscinia megarhynchus Brehm, 1831, more wavering notes reminiscent of Blackbird Turdus merula L., 1758, as well as coarser repetitive notes comparable to those of Sedge Warbler Acrocephalus schoenobaenus (L., 1758), all continuing for long-extended periods of time, usually ending with a more feeble Blackcap-like rendition. The insistency of the performance and extent of the mimicry at times recalled Marsh Warbler Acrocephalus palustris (Bechstein, 1798).

I had no optical aids to hand and as the bird moved through the crowns of cherry trees with developing foliage it proved difficult to see. Eventually I achieved reasonable proximity to it as it sang from a large Blackberry clump in which it was clearly moving but could not be seen. Sensing where the bird might be in the clump I took numerous photographic images and later examined them at high magnification. One of these showed the head of a bird in enough clarity for it to be identified positively as a male Blackcap.

The normal mellifluous rich fluty cadence of the Blackcap is well-known and readily recognised. There are text references to the Blackcap's ability to produce a mimetic sub-song but a strong consistent performance such as this for hours on end was not something I had previous experience of.