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Monday 29 June 2020

Third-summer (4cy) Mediterranean Gull

Following on from my last post, I have received the details of green-ringed Med Gull RX2P.  A cracking looking bird that I saw on the Axe Estuary at 9am on 27th June.  It makes interesting reading...

Firstly, incredibly this bird was also sighted in Weymouth on 27th June!  Looking at the EXIF data of the Weymouth photograph it was taken at 5:15pm, and although not all that surprising a gull has travelled 30 miles along the coast in a day, it's gone the opposite way to what I'd expect!  The Med Gull passage off the south west coast at this time of year is usually a westward one so it's gone the wrong way!



Secondly, and something that really excites the guller in me, is that it was ringed as a pullus in Paris on 02/07/17. A quick tot up on my fingers tells me this bird is in it's fourth calendar year (4cy) and it's third-summer plumage.  This is not something I have ever written before for a Med Gull as it shouldn't be an identifiable age-class, with the usual ageing process as follows;

Juvenile - First-winter - First-summer - Second-winter - Second-summer - Adult.

Or if you prefer using calendar years (cy) and not plumage cycles;

1cy - 2cy - 3cy - Adult.

However in the past I've seen some second-winter/second-summer Meds with such a restricted amount of black in the primaries that I've wondered if they were actually a year older. From how RX2P looked the other day, it turns out they probably were!

This is a typical second-summer Med Gull taken on the Axe Estuary on 29/03/11...

Not the best photo but black and white primary tips obvious


And here's a typical looking second-winter Med Gull taken on the Axe Estuary on 2/12/11...

Clearly overcast when I took this photo!


Here is RX2P...

Nearly adult but not quite! Small black streak on otherwise white primaries

A more distant view but shows how little black there is


So what does this mean for the 'second-winter' and 'second-summer' labelling of Med Gulls? Well a bird with a typical amount on black I suspect the ageing remains correct, but for anything showing less 'second or third winter/summer' would probably be a more accurate caption.  For example, let's look at the unringed Med Gull that RX2P was accompanied by...

Looks quite similar doesn't it!


It has a bigger black smudge than RX2P on its otherwise white primaries but it's only one smudge and is far less than the average second-summer.  It has to be a good candidate for another third-summer surely?  

I'm going to have to do some more digging I think and see what other colour-ring sightings have shown.

Gulls, is there no end to the happiness and wonder they give me?  If there is I am a long way from it that's for sure.


4 comments:

  1. Steve, Olsen & Larsson says re 3rd-winter (and hence 3rd-summer too, prior to primary moult later in year): 'P8-10 sometimes with short dark markings to outer Web (present in 25% of third-winter males and 50% of third-winter females)'.
    So you're right. Definitely not 2nd-summer birds.

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    1. Thanks Gav, interesting to read! The benefit of ringing though, good to be reminded it still has a place in modern day ornithology

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  2. To repeat Gav, age-able 3w not uncommon (should be about a third of 3w birds according to Malling-Olsen) - I've got a collection of photos of such. The problem is markings often limited to a small smudge on P9 so only visible on spread wing and rarely something you'd notice in the field; from a series of photos however. . .

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    1. Thanks Tim - good stuff. And yes, cameras are certainly helping us a lot in ID/ageing this day and age

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