Edward Stubbings
On the afternoon of 11th December 2010, while ringing at Kelling with my ringing trainer, I caught a Treecreeper which was immediately striking due to its pale, ‘frosty’ appearance. Knowing that it was potentially a Treecreeper of the northern European nominate form, we noted its basic plumage features, took a series of measurements and, despite the failing light, secured some photographs. A summary of the bird’s features is set out below.
Plumage
The bird was indeed pale and ‘frosty’, being strongly lined white on its upperparts, accentuating the contrast with a strongly rufous rump. The supercilium, including the fore-supercilium, was bold, broad and clean white. The whole underparts, including the flanks, were similarly bright silky white with only the faintest of buff washes on the undertail coverts.
Measurements
The two most significant measurements were the bill and hind claw and, for each, the mean of three measurements was taken. The bill length of 20mm fell outside that of britannica (14.3-19.1) but within that of familiaris (14.6-20.8) whilst, at 9.9mm, the hind claw was also outside the range of British birds (7.8-9.7) but within that of Northern Treecreeper (8.2-11.6).
Discussion
Given that the bird was both described and photographed and that all the plumage features and measurements were fully consistent with Northern Treecreeper and outside the range of britannica, the County Records Committee has accepted the bird as familiaris.
This is, of course, a significant record. There has long been speculation that Northern Treecreepers may occur in the county, indeed two records are listed in Taylor et al. 1999 and also feature in the Norfolk Bird Report - Weybourne on 4th November 1978 and Holme on 2nd November 1987. However, there is no indication in these sources that either of these birds was trapped, nor are any supporting details published or available. This bird therefore provides the first opportunity to fully document what is presumably a rare bird in Norfolk. Given the new focus on the documentation of scarce and rare bird forms in the county now promoted by the Bird Report, we can hopefully look forward to further records of this form in future, though measurements and photographs would appear to be minimum requirements for acceptance.
References
Cramp, S. (ed.). (1985). The Birds of the Western Palearctic. Vol VII. Oxford University Press.
Seago, M.J. (ed.). Norfolk Bird and Mammal Reports 1978 and 1987. Norfolk and Norwich Naturalists’ Society.
Svensson, L. (1992). Identification Guide to European Passerines. Privately published.
Taylor et al. (1999). The Birds of Norfolk. Pica Press.
On the afternoon of 11th December 2010, while ringing at Kelling with my ringing trainer, I caught a Treecreeper which was immediately striking due to its pale, ‘frosty’ appearance. Knowing that it was potentially a Treecreeper of the northern European nominate form, we noted its basic plumage features, took a series of measurements and, despite the failing light, secured some photographs. A summary of the bird’s features is set out below.
Plumage
The bird was indeed pale and ‘frosty’, being strongly lined white on its upperparts, accentuating the contrast with a strongly rufous rump. The supercilium, including the fore-supercilium, was bold, broad and clean white. The whole underparts, including the flanks, were similarly bright silky white with only the faintest of buff washes on the undertail coverts.
Measurements
The two most significant measurements were the bill and hind claw and, for each, the mean of three measurements was taken. The bill length of 20mm fell outside that of britannica (14.3-19.1) but within that of familiaris (14.6-20.8) whilst, at 9.9mm, the hind claw was also outside the range of British birds (7.8-9.7) but within that of Northern Treecreeper (8.2-11.6).
Discussion
Given that the bird was both described and photographed and that all the plumage features and measurements were fully consistent with Northern Treecreeper and outside the range of britannica, the County Records Committee has accepted the bird as familiaris.
This is, of course, a significant record. There has long been speculation that Northern Treecreepers may occur in the county, indeed two records are listed in Taylor et al. 1999 and also feature in the Norfolk Bird Report - Weybourne on 4th November 1978 and Holme on 2nd November 1987. However, there is no indication in these sources that either of these birds was trapped, nor are any supporting details published or available. This bird therefore provides the first opportunity to fully document what is presumably a rare bird in Norfolk. Given the new focus on the documentation of scarce and rare bird forms in the county now promoted by the Bird Report, we can hopefully look forward to further records of this form in future, though measurements and photographs would appear to be minimum requirements for acceptance.
References
Cramp, S. (ed.). (1985). The Birds of the Western Palearctic. Vol VII. Oxford University Press.
Seago, M.J. (ed.). Norfolk Bird and Mammal Reports 1978 and 1987. Norfolk and Norwich Naturalists’ Society.
Svensson, L. (1992). Identification Guide to European Passerines. Privately published.
Taylor et al. (1999). The Birds of Norfolk. Pica Press.
