The Dartford Warbler in Kent

R.C.Stone

The last recorded breeding of the Dartford Warbler (Sylvia undata) in Kent was on Hayes Common in 1891 (Ticehurst and Harrison). The purpose of this paper is to assemble and consider the Kent records since that year.

A female Dartford Warbler was recorded at Dungeness on Oct. 28th 1914 , and another bird was seen at the Hoppen Pits by the watcher (J. R. Tart) on June 4th 1926 (Harrison).

The next record is of two at Westwood (north of Hythe) at the end of October 1937 (Harrison). These, presumably, were shot by G. Mannering and are in the Maidstone Museum. Twenty years followed without a published record until an adult female was trapped and ringed at Dungeness on Oct. 19th 1957. I was present when this bird was released by H. E. Axell and recall it perched on some low broom near the Observatory. Another bird (unringed) was seen on October 26th-27th. On November 16th in the same year my attention was drawn by a Whitethroat like "churr" from a kale field at Boyton Court, East Sutton and I saw a Dartford Warbler flying from cover.

The bird was seen again by myself or other-observers on seven or eight days up to December 29th, by which time most of the kale, beneath which it seemed to spend most of its time, had been eaten off by cattle. Apart from the Westwood birds, this seems to be the only record away from Dungeness during this century.

The next record at Dungeness was on Dec. 17th 1960, a year in which vagrants were reported at Portland (Dorset), Titchfield Haven (Hants) and Walton-in- Gordano (Somerset), all on October 16th, and near Prawle Point (Devon) three days earlier, on the 13th.

The breeding population of Dartford Warblers in the New Forest and elsewhere had been building up because of a series of mild winters and in 1961 was estimated at 450 pairs (Tubbs). This build-up was reflected at Dungeness by the occurrence of four-five birds between November 5th and 26th and single(s) on December 3rd and 26th. Two trapped were adult and first winter males. Birds were seen also on Feb. 18th and 19th 1962; one was ringed on Mar. 11th and another seen on Mar. 13th. Severe weather early in that year brought about a crash in the breeding population of Dartford Warblers, especially in Hampshire. A bird was, however seen at Dungeness on Oct. 14th.

The ever memorable winter of 1962/63 followed, when the British population, already greatly depleted, was almost wiped out. No more records came from Dungeness until Feb. 22nd 1967, by which time there had been a small recovery. Since then birds have been seen on the rather unusual date of July 30th 1970 and, less unexpectedly, on Oct. 18th 1970 and Oct. 30th-31st 1971 .

The following table summarizes the records for Kent this century. Each record is shown only in the month that the bird was first seen.

Clearly, October is the likeliest time to find a Dartford Warbler in Kent, and post-breeding dispersal, especially after a good season, is the main factor. Whether the birds come from Sussex , where a few nest, from Hampshire or from further afield, it seems difficult to say. The July bird might possibly be of foreign origin, as it occurred at a time when other southern migrants were seen. It may be significant that none has so far been recorded from Sandwich Bay, the movement seems to be along the south coast. In the Eastern counties most recent records seem to be of one at Walberswick, Suffolk about 1939, and a pair most surprisingly nesting near Frinton, Essex in 1948. Dartford Warblers ceased to breed in Suffolk about 1917. Bannerman remarks that 'a certain amount of Iocal movement takes place in autumn, some birds at any rate leading a more or less nomadic existence when they may be encountered on almost any sort of rough ground, for choice where small bushes can serve as cover; even fields of roots are visited in winter' and he quotes Walpole-Bond as believing that in Sussex the Dartford Warblers are inclined to make for the low ground near the coast.

Away from the Observatories, it is only by the greatest good luck that a Dartford Warbler will be spotted in autumn or winter. On dull days especially the birds keep closely to cover.

References

Bannerman, D. A. (1954) 'The Birds of the British Isles' Vol. II, p. 158.

Cohen, E. (1963) 'Birds of Hampshire and the Isle of Wight'

des Forges, G. and Harber , D. D. (1963) 'A Guide to the Birds of Sussex'

Dungeness Bird Observatory 1952-62 and 1967. Harrison, J. M. (1953) 'The Birds of Kent' Vol. II, pp. 187-88.

Hudson, R. and Pyman , C. A. (1968) 'A Guide to the Birds of Essex'.

Payn , W. H. (1961) 'The Birds of Suffolk'.

Tioehurst , N. F. (1909) 'The Birds of Kent'.

Tubbs, C. R. (1967) Numbers of Dartford Warblers in England during 1962-66. British Birds. 60: 87-89.