Sunday 31 August 2014

How many species of gull in this photo?

30th August 2014 - Topsham

I took this photo at Topsham Recreation Ground yesterday. Three adult gulls, clearly three different 'types' but are there three species involved or just two?

OK that was clearly a leading question and regular readers of this blog will know where this is going. Those who, inexplicably, find gulls uninteresting might want to skip to the end of this post for a photo of a Tree Pipit.

Larus spp. 30/8/2014 Topsham

The middle and right hand birds should present no problems - Herring Gull and Lesser Black-backed Gull - but what about the bird on the left? Medium grey mantle - good for Yellow-legged Gull if perhaps a little 'blue' - but pink legs? I think it's clear we're looking at another hybrid, the parents presumably being Herring and Lesser Black-backed.

Here's some photos showing the primaries more clearly. As you'd expect in late August it's in moult but the relevant feathers are all present. P1-5 are new and fully grown, P6 is nearly so, the old P7 has been shed and the replaced feather is not yet visible, P8-10 are old. There are good sized mirrors on P9 and P10 with a fair amount of black on the outer three primaries and, unlike many apparent hybrids, there is a complete black band on P5 - the overall pattern suggesting michahellis or graellsii rather than argenteus.

Larus hybrid 30/8/2014 Topsham

Larus hybrid 30/8/2014 Topsham

So my answer is: three gulls, two species, presumably one and a half Herring and one and a half Lesser Black-backed (I do realise it may not be that simple since it can't be ruled out that there's also some michahellis mixed up in there and of course it might not be a first generation cross). Never a dull moment with gulls or, to quote a good friend of mine: "welcome to the wonderful world of Larids!"

Meanwhile, here's the Tree Pipit (one of two) taken from the back door a couple of days ago. It's not a garden tick - I've had a few flyovers before - but it is the first one actually in the garden.

Tree Pipit - 29/8/2014 Topsham

No comments:

Post a Comment