Melanistic Lesser Black-backed Gull, Richmond Bank, Cheshire, March 2010

On the 8th March 2010, my regular gull watching companion Pete Berry located a very odd looking bird on the mudflat at Richmond Bank, Cheshire that took him somewhat by surprise. The realisation quickly dawned on him that is was in fact an almost all black large gull! Pete quickly drew my attention to the bird and we watched the 'sooty' individual for well over an hour.

It was a remarkable looking bird to say the least and neither of us with our combined 40 years of serious gull watching had seen anything remotely similar. We presumed the individual to be a Lesser Black-backed Gull Larus fuscus graellsii due to it's overall structure along with a small area of 'normal' leg colouration. Due to it's bare part colouration the bird was aged as an adult.

Initially, I harboured doubts about the bird being truly melanistic, mainly due to my complete lack of knowledge and experience of such individuals and that it's bizarre appearance was most likely due to discolouration of some kind. However, our combined close study and considered approach quickly dispelled that theory and the realisation that the bird was indeed truly melanistic suddenly became apparent, especially after the bird made a short flight around the mud flat in front of us.

Essentially the bird appeared entirely black/charcoal grey apart from an entirely silvery white crown, nape and hindneck, rather sharply demarcated against the darkness of the rest of the plumage and overall was vaguely reminiscent of a huge Western Jackdaw Corvus monedula spermologus. Closer inspection found that the bird's 'face' was particularly deep black but the foreneck and entire underparts were charcoal/grey and entirely even in colouration, lacking any blotching or patchy effect. The mantle, back and scapulars were very deep black whilst the entire upper and underwings apart from the secondaries and primary tips, were very slightly paler, though still a very dark charcoal/grey. The secondaries on each wing were evidently white tipped, creating the more usual distinct white trailing edge to the inner wings clearly evident in flight. The primaries similarly exhibited small white tips although their colour appeared slightly less pure white than the secondaries. From beneath, the tail appeared dark charcoal/grey yet the upperside displayed prominent silvery white in flight though the extent of this colour across both webs of the tail feathers was not fully ascertained. The eyes and bill were consistent in colouration to those of a typical adult Lesser Black-backed Gull but the legs were solidly deep black but for the very rear of the lower section of tarsus on each leg which was patently yellow. The bird behaved perfectly normally in every aspect, never appearing sickly and the entire evenness and complete symmetry of the black colouration throughout the bird left us in little doubt that it was indeed truly melanistic. Perhaps surprisingly given it's remarkable appearance, the many thousands of Lesser Black-backed Gulls Larus fuscus intermedius and Herring Gulls Larus argentatus argenteus surrounding it never seemed concerned by it's presence at any time.

Reference made to apparent melanistic Black-headed Gulls in Kent, March 1998 (M. J. Orchard) and on Orkney, July 1996 (Roderick H. F. Thorne) bear some similarities to the Richmond Bank bird, not least in their shared characteristic of having the nape as clearly the palest part of the plumage.

Please bear in mind that all the photos below were digiscoped at long range, most at 60x magnification and in an often dreadful heat haze, so whilst their quality is distinctly below par I am only pleased anything exists at all!

Above: The 'sooty gull'. Remarkable and unmistakeable in appearance amongst it's more normal counterparts.

Above: Notice how 'smooth' and uniform the sooty black on the underparts and face is. It was not blotchy or inconsistent anywhere on the entire birds plumage and was in fact particularly symmetrical in it's hue and extent. The bill can be seen to be rather typically yellowish with a patent reddish goyns. The iris was 'normal' yellowish in colouration.

Above: Again, the uniformity of the underparts is apparent as are the apparently jet black legs. Note here how the bill appears slightly darker but did not appear as such in the field. One of the more peculiar features the bird possessed was the silvery white crown and hindneck, rather sharply demarcated against the fore-neck and certainly so with the mantle though somehow over exaggerated slightly in the image.

Above: The underside of the tail too appears rather uniformly black although the uppertail was certainly more silvery coloured.

Above: The extent of the silvery crown and hindneck is clear here although it's colour was enhanced and appeared and more whitish whenever the neck was stretched.

Above: Once again the bizarre silvery hindneck contrasts sharply against the blackness of the rest of the plumage. In the field the mantle appeared truly deep and solid black and the wings very slightly less so but still entirely uniform in distribution of colour. The primaries can clearly be seen to possess the usual white tips found in adults. Although the legs were certainly black the very bottom of the rear of the tarsus was in fact yellow but was extremely restricted in it's distribution and was symmetrical on both feet. We unfortunately did not ascertain if the yellow colouration extended onto the feet and webs.

Above: The 'sooty' gull with a Carrion Crow for comparison!

References

Orchard, M. J. 1998. Presumed melanistic Black-headed Gull. British Birds 91:12, 561-563

Thorne, Roderick H. F. 1996. Melanistic Black-headed Gull. British Birds 89: 12, 569-570

Acknowledgements

My thanks to Pete Berry for our seemingly hours of discussion and his own research into this bird.

Ian McKerchar, November 2010

BACK TO THE IDENTIFICATION ISSUES HOMEPAGE

BACK TO THE MANCHESTER BIRDING HOMEPAGE