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

Terns on the river

27th August 2014 - Topsham

It seems there was something of a tern movement in south Devon yesterday, I almost missed out. I should really have been down at Exmouth I suppose but still managed to see a few. While on my way to check Bowling Green Marsh I stopped on the Goatwalk to scan the estuary and noticed a group of 15 Common Terns hanging around a buoy in mid channel.

Common Terns - 27/8/2014 Topsham - part of a group of 15, 3 adults and 12 juvs

Common Terns - 27/8/2014 Topsham - part of a group of 15, 3 adults and 12 juvs

They flew my way, overhead and silhouetted against a grey sky, heading east so I moved on to Bowling Green Marsh where I hoped to find them again. But that was it, they were gone. Just as puzzling was the almost complete lack of gulls both at BGM and at Goosemoor - usually at high tide there are hundreds if not thousands. Perhaps something to do with the new hide construction?

Just for a change - a Yellow-legged Gull

August 18th 2014 - Topsham

This is a pretty straightforward 1st year michahellis. The whitish head and body with nice and contrasty mantle and wings made it stand out even before I raised my bins. A closer look soon confirmed my suspicions, luckily it also stayed around for a few photos.

Yellow-legged Gull 1cy - 18/8/2014 Topsham

Yellow-legged Gull 1cy - 18/8/2014 Topsham

Yellow-legged Gull 1cy - 18/8/2014 Topsham

Tertials with thin pale fringes not reaching base, dark wedge at base of outer greater coverts, median and lesser coverts simple pattern with little or no barring. Many scapulars replaced already - see the anchor-marks - whereas most/all HG and LBBG still showing all juvenile scapulars. Rump, upper tail coverts and base of tail white and contrasting with a neat black tail band.

And if that's not enough, some flight views showing a classic tail pattern and dark wing - though with a only faint 'window' due to the slightly paler inner webs to the inner primaries

Yellow-legged Gull 1cy - 18/8/2014 Topsham

Yellow-legged Gull 1cy - 18/8/2014 Topsham

Yellow-legged Gull 1cy - 18/8/2014 Topsham

Yellow-legged Gull 1cy - 18/8/2014 Topsham

Yellow-legged Gull 1cy - 18/8/2014 Topsham

A few common or garden flies

12th August 2014 - Topsham

I know they can be a nuisance, I know some of them spread diseases and I'll admit many have rather unsavoury lifestyles but take a close look at a fly and tell me they're not amazing. I've been pottering about the garden with my macro lens and, as usual, it's been mostly flies. Conditions haven't been perfect but occasionally the sun goes in (photos of shiny insects in bright sun look dreadful) and the wind drops (with exposure times of 1/5 second you don't want the subject moving at all). Here's a few mostly common species, all named using the appropriate identification keys.

Lucilia sericata Calliphoridae - 12/8/2014 Topsham

This is a common greenbottle (also known as the sheep blowfly) Lucilia sericata. Identified by the pale basicosta (that whitish nubbin at the base of the wing) and, as it's a male, by the widely separated eyes (Erzinçlioglu 1996). There are seven British species of Lucilia and this is one of only two which are safely named from a photo, for the rest you're going to need a male specimen and a microscope.

Eristalis tenax Syrphidae - 12/8/2014 Topsham

Here's a very common hoverfly Eristalis tenax, also known as a drone fly as it's a honey bee mimic - even down to the fake pollen baskets on it back legs. Identification is pretty straightforward based on the broad black stripe down the face and vertical bands on the eyes (Stubbs & Falk 2002).

Scathophaga stercoraria Scathophagidae - 12/8/2014 Topsham

Another easily recognised species, this is the common yellow dung fly Scathophaga stercoraria, safely told from the other nine British Scathophaga spp. by the conspicuously black antennae (Ball 2007).

Nemorilla floralis Tachinidae -12/8/2014 Topsham

This one, a parasite fly or Tachinid, is rather less straightforward to identify. It does show the general appearance of the family - strongly kinked medial wing vein, 'delta wing' posture and it's strikingly bristly; another useful pointer is the slow purposeful hunting flight when searching for a host (in this case caterpillars) in which to lay its eggs. I've photographed this species a few times in the garden over recent years, identified using Belshaw 1993 and confirmed by the experts at diptera.info.

References

Ball, S.G. 2007; Key to the British Scathophagidae (Diptera), Version 3.1
Belshaw, R. 1993. Tachinid flies. Diptera: Tachinidae. Handbooks for the identification of British Insects. Royal Entomological Society of London 10, Part 4a(i).
Erzinçlioglu, Z. 1996; Blowflies. Naturalists' Handbooks 23. The Richmond Publishing Co.
Stubbs, A.E. & Falk, S.J. 2002. British Hoverflies. British Entomological and Natural History Society.

More Yellow-legged Gull...and why not?

6th August 2014 - Topsham

The Ross's Gull is gone it seems, I hope it may still be around as it would be great to see it finish moult. The Exe Estuary's purple patch continues though with Matt Knott's spectacular find of a Caspian Tern at Exmouth yesterday. For Matt's account see his blog at birding exmouth, with the sequel here. Chris Townend also got some 'record shots'. A big thank you to Matt for the texts/calls and to Chris for the scope views. I got there just in time to see it fly up river, after a further sighting at Exmouth later that afternoon it appears to have moved on.

That doesn't mean that as I cycled down to the Rec this morning I didn't entertain at least a small hope that a huge red-billed tern might be sitting out there on the shingle waiting for me. Needless to say, the anticipated tern had other ideas and failed to show.

As some form of compensation I did find another Yellow-legged Gull. One of this year's brood newly arrived from further south, though exactly where is an interesting question.

Here's how it first looked, preening on the water's edge and showing bright white upper tail coverts and rump, with a black tail band, narrowing to the outer tail feathers and with a lot of clean white on the outer web of R6.

Yellow-legged Gull juv-1W 6/8/2014 Topsham

Yellow-legged Gull juv-1W 6/8/2014 Topsham

Preening continued, scapulars with simple pale fringes, reasonably worn and with one or two second generation feathers appearing. Tertials also thinly fringed, white not reaching greater coverts and quite worn at the tips. You might say it's no longer in full juvenile plumage but is a bird moulting to first winter plumage, maybe it's simpler to call it 1st cycle.

Yellow-legged Gull juv-1W 6/8/2014 Topsham

With juvenile Lesser Black-backed and Herring Gulls for comparison, and on it's own.

Yellow-legged Gull juv-1W (with LBBG left and HG right) 6/8/2014 Topsham

Yellow-legged Gull juv-1W 6/8/2014 Topsham

Yellow-legged Gull juv-1W 6/8/2014 Topsham

And the spread wing? Nice and dark with pale only on the inner webs of the inner primaries.

Yellow-legged Gull juv-1W (with HG left) 6/8/2014 Topsham

Yellow-legged Gull juv-1W 6/8/2014 Topsham

 It's perhaps a little fresher and less worn than is typical of a Mediterranean bird in August, I wonder if it's from an Iberian population - supposedly later fledging and therefore less advanced?

Adult Yellow-legged Gull - I suppose...

31st July 2014 - Topsham

I paid my daily visit to the Ross's Gull. Today it was venturing further up river from its favourite spot opposite the Retreat, after nice close views on the shore by Newcourt Park (see photos below) it flew upstream and I followed, I found it feeding by the outflow north of the water treatment works.

On my way back I found this among the Herring and Lesser Black-backed Gulls on the spit.

pres. Yellow-legged Gull - 31/7/2014 Topsham

pres. Yellow-legged Gull - 31/7/2014 Topsham

pres. Yellow-legged Gull - 31/7/2014 Topsham

pres. Yellow-legged Gull - 31/7/2014 Topsham

pres. Yellow-legged Gull - 31/7/2014 Topsham

pres. Yellow-legged Gull - 31/7/2014 Topsham

The mantle is clearly darker than a Herring Gull and the legs are yellow (or yellowish, they are quite pale but that might not be unusual on a post-breeding bird), the bill looks a good shape, the orbital ring looks like it might be dark red (impossible to be sure from these photos) and there's a lot of black on the primaries - particularly so on P8. So why can't I just call it a Yellow-legged Gull? My suspicious mind - I've seen too many probable hybrids here in recent years, many of which have aroused doubt due to their odd primary pattern. The give away on most birds has been a broken black band on P5. The only problem with this moulting bird is that P5 is not visible yet (nor is P6). I waited a few minutes hoping it would fly and show the tip at least of a growing P5, I turned away for a few seconds and it vanished. I heard from Keith Birchall that an adult michahellis had been reported here the previous day, it might reappear.

Meanwhile, as promised, here's some more of the Ross's Gull. Still looking decidedly tatty but primary moult progressing nicely; P1-5 new, P6 growing (though still too short to see) and P7-10 old, still no change in the secondaries and tail feathers though.

Ross's Gull - 31/7/2014 Topsham

Ross's Gull - 31/7/2014 Topsham