I’m a bit weak on Gull identification

I’m writing this today, Saturday, with snow still covering Somerset, trying to remember last Tuesday. It seems as if an entire season has passed and that last Tuesday happened sometime during a previous summer. If it hadn’t been for the low position of the sun, casting long mid-morning shadows, I could well have believed that I was experiencing one of those rare dry and even rarer, sunny, days of a summer past. I had decided to walk with the dogs across the fields towards Brean Down, a towering coastal peninsula that jutts out into the Bristol Channel and is almost the last uprising of the Mendip Hills before they disappear into the sea, and then north along the sands below Weston Super Mare.

At low tide here the shore line birds are usually far out across the mud flats and impossible to reach, but this morning, by luck rather than by judgement, the tide was still high over the sands, so that the few sea birds that had chosen this short strip of coastline to search for food were still close enough to approach on firm sand.

Distinctive amongst the usual assortment of crows and gulls was a small group of oystercatchers. These are distinctive birds with long red bills, red legs, mad red eyes and glossy black and white plumage. Despite its name oysters do not form a large part of its diet which is varied and dependent on habitat. Coastal oystercatchers prey upon limpets, mussels, gastropods, and chitons, whilst those on estuaries hunt for bivalves, gastropods and polychaete worms. Species occurring inland feed upon earthworms and insect larvae.

Oystercatcher
Eurasian Oystercatcher (Haematopus ostralegus)

One noticable variation in sub-species is the shape of the bill which is determined by diet. Birds with broad bill tips open molluscs by prising them apart or hammering through the shell, whilst those with pointed bill tips tend to probe for worms. Juveniles watch and learn technique from their parents so a young individuals final bill shape will be defined by the habitat they grow up in.

Small group of Oystercatchers
These have a slightly different bill shape

As its name suggests, the redshank’s most distinctive features are its bright orange legs and slender orange bill that looks as if it has been dipped in black ink.

Redshank
Redshank (Tringa totanus)

A member of the Sandpiper family, redshanks spend much of the winter on estuaries and coastal lagoons with as many as half of these birds having migrated from Iceland. Like the larger oystercatches these elegant little birds hunt for insects, earthworms, molluscs and crustaceans by probing their bills into the mud.

Redshank
Redshank (Tringa totanus)

The problem with identifying gulls is that there are so many species and sub-species, all with subtle and often seasonal differences. So having taken some quite good identification shots and confident that my wife, an experienced bird watcher and fount of all knowledge, would be able to identify them for me I was a bit surprised when she said: “Dunno, gulls are difficult.”

Lesser Black-backed Gull
Lesser Black-backed Gull

So after several hours of intense study I believe that this is a lesser black-backed gull (Larus fuscus) and that this may be an adolescent; or an adult in winter plumage. You see the problem developing here? You know where you are with an oystercatcher or a redshank, but with gulls it’s all a bit vague.

Lesser Black-backed Gull
Lesser Black-backed Gull

This after extensive research I am fairly confident is a herring gull (Larus argentatus) or it could be another lesser black-backed gull……

Herring Gull
Herring Gull

This is a tricky one. The plumage suggests that this is a yellow legged gull (Larus michahellis), but with pale green legs and bill? Well if anyone reading this does know I would be gratefull if they would share their knowledge.

Juvenille Yellow-legged Gull, or is it?
Juvenille Yellow-legged Gull, or is it?

Sunday: further investigation, we got out all the bird books, reveals that this is probably a second winter common gull (Larus canus). Strangely, common gulls are not very common at all.

Later on Sunday: turns out that the herring gull is another lesser black-backed gull.

Advertisements

Author: Hares on the Hill

I am a designer and photographer. I live with my wife and our two dogs in the Welsh Marches, a land full of history, legends, mountains, rivers and dragon's breath; a place where animism thrives. To our north are the Cambrian Mountains, the Elenydd, a vast plateau so ancient that its mountains now have the appearance of steeply rounded moorland hills; to the east is England; to the south stand the Black Mountains and in the west the Brecon Beacons rise around the twin summits of Pen y Fan and Corn Du, the highest mountain in West Wales.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s