As the tide rose around forty Dark-bellied Brent Geese fed on the water's edge to the east of the causeway ... sometimes swimming in the shallows ... and with them, a Black Brant ...
... the appearance of the Brant puzzled me slightly in terms of some of its features ... while it was distinct from the Brents it looked rather different from the Brants that I had previously seen in Norfolk over the years ... the white neck collar seemed less bold and the white flank markings looked less intensely white and was interrupted by greyish bars ... structurally the neck was less obviously thicker than those of the Brents although the forehead was more domed ( as it should be ) in comparison with the Brents ...
... here some Brents feed together, the changing attitudes of the birds giving them ever changing colour tones in the weak sunshine ...
But alongside the Brents, the Black Brant is distinct ...
... here the head shape looks distinctive as the Brant swims behind a Brent ...
... and some video-grabs as the Brant leaves the water ...
Here is a small group of Pale-bellied Brents in the Walney Channel at Barrow ...
... and on the rising tide a flock of around eighty flew in distantly on the west side of the causeway before departing towards Walney Island ...
Still puzzled by what I took to be the atypical appearance of the Brant I checked previous images of the bird taken by others ... it was clearly the same individual ... the niggling doubt that I had was around the purity of the bird ... could it be a hybrid ? ... it strongly reminded me of Black Brant x Dark-bellied Brent hybrids that I saw in Norfolk some years ago ...
I consulted Andy Stoddart on this.
Andy writes -
The key feature to look for would be the presence of dark earth-brown hues (as opposed to grey) in the upperparts and breast ... The flanks and neck collar look to be within the range of variation of Black Brant and the breast/belly contrast looks suitably minimal so, unless the bird was strongly grey-hued, I wouldn't necessarily call it a hybrid based on your images.
Ends.
... having checked further images, the colour tones concerned showed dark brown rather than grey ... and with concerns around the neck collar and flanks allayed, thoughts of hybrid origin faded ...
... a very useful learning experience ... I'm grateful to Andy for his input ...
Interestingly a couple of taxonomic quirks came to light as I was reading around the Brent Goose complex -
- the name Brent is apparently a corruption of Brant and was introduced erroneously by Pennant in the 1800s
- Black Brant originally Branta bernicla nigricans became B.b.orientalis when it was discovered that the type specimen was not a Black Brant but a Grey-bellied Brent which thus acquired the scientific name B.b.nigricans
There have been those who advocated splitting the races of Brent Goose (including Black Brant ) into three of four species but the current IOC position keeps then as a single species.
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