Published on 13 March 2014 in Letters

In the Recent reports section of the February 2009 issue of BB, a photograph of a goose taken at Wells, Norfolk, by Gary Thoburn (plate 73) is captioned as being an adult `Black Brant’ Branta bernicla nigricans. From experience gleaned through the years in north Norfolk, I would say that the bird is in fact an intergrade ­ between a dark-bellied Brent Goose Branta b. bernicla and a `Black Brant’. The bird is too grey on the back and breast/upper belly for a typical Black Brant, despite having a well-marked white neck-collar and flank patch that would suggest that form. In north Norfolk, mixed pairings of Black Brants and dark-bellied Brents with hybrid offspring have been noted at Burnham Deepdale/ Burnham Norton in January­February 2001 (with four hybrid juveniles), Wells/Holkham in the winter of 2004/05 (with two hybrid juveniles) and in the winter of 2005/06 (with three hybrid juveniles) (Bloomfield & McCallum 2001; Norfolk Bird Reports 2001­2007). Since then there have been at least three returning birds showing mixed characters such as those depicted in plate 73 (good neckcollars and flank patches but far too grey on upperparts and breast) in the Burnham area and at least two (but maybe more) in the Wells/Holkham area, one of which is the bird portrayed in BB. With mixed breeding seemingly occurring more regularly than previously suspected, the pitfall of intergrades is something that certainly needs to be considered when confronted by a likely Black Brant candidate.Andrew Bloomfield 20 Lancaster Road, Blenheim Park,

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