Page 1 of 2

Head-streaked michahellis or Azorean atlantis?

Posted: Mon Apr 08, 2013 9:42 am
by richard lowe
Hi all - this unusual second winter 'michahellis' - type was videod with a 3w Iceland Gull at Poolsbrook Country Park, Staveley, Derbyshire, U.K. on 27th March 2013. The general plumage seems OK for 'michahellis' other than the well demarcated heavily streaked 'hood'. I have never seen this degree of head streaking in the spring. Although a feature of Azorean 'atlantis' it just didn't gel as one to me but I would greatly value any comments you may have.
Not seen in flight and no other pics available - sorry! (Incidentally, the eye rim is red - not readily visible on the attached video-grab. Bright sunlight has slightly burned-out the nape streaking - in real life the hood was fairly even, other than the 'face' which can be seen to be 'duskier'.)

Best wishes to you all, Richard Lowe (Derbyshire, U.K.)

Re: Head-streaked michahellis or Azorean atlantis?

Posted: Tue Apr 09, 2013 7:08 pm
by marsmuusse
Hi Richard,
Of course could be interesting if it is atlantis, but key probably is ruling out March 3CY micha. 2nd winter birds may still have streaking in March, but April would be late. I checked a few pictures on GullResearchOrg and digged up a few oldies from Etaples (near Boulogne-sur-Mer) NW France:
http://gull-research.org/ylgadsubad/3cy ... ha9117.htm - 17 March 2003:
Image

Another one of these birds also has head streaking. A few more on http://gull-research.org/ylgadsubad/3cy ... 3cymar.htm
Sorry, its only just afew birds, but there are more websites on michahellis on the web.

Not really as hooded as your bird, but once streaking is possible you probably end up in a discussion where do streaks end and does a hood starts?
But see the bird below, from exactly your date, albeit photographed in Rome (so latitude may be important):
Image

Of course, here is a link to atlantis:
http://gull-research.org/atlantis/3cymarch.html
Note some appear hooded, but these birds (Madeira, not Azores!) are not necessarily hooded, some may show streaks even down in the hind neck.

Re: Head-streaked michahellis or Azorean atlantis?

Posted: Wed Apr 10, 2013 9:13 am
by richard lowe
Many thanks, Mars. Azorean 'atlantis' would seem a difficult bird to nail - moult would have to be a key feature but there appear to be no anomalies with 'michahellis' on this bird. Worth a try though.....
Regards, Richard.

Re: Head-streaked michahellis or Azorean atlantis?

Posted: Wed Apr 10, 2013 9:45 am
by richard lowe
Just thought I would post a couple of pics of 3cy Azorean 'atlantis', courtesy of the excellent 'Birding Azores' website, both taken Jan/Feb, for comparison.
Richard Lowe.

Re: Head-streaked michahellis or Azorean atlantis?

Posted: Wed Apr 10, 2013 11:07 am
by adriaens
To be honest I am not even sure that this bird is a 2nd winter; note the distinct white primary spots, which seem to indicate 3rd winter.
I am also not sure that it is not a Herring Gull...

Re: Head-streaked michahellis or Azorean atlantis?

Posted: Wed Apr 10, 2013 5:20 pm
by JanJ
Ageing can be tricky from this pic but as Peter suggest - those distinct white primary tips would indicate an older bird. However, other plumage features could well indicate a younger bird.
This - http://waarneming.nl/foto/view/3121527 - 3cy type bird shows no direct signs of white primary tips but in this pic - http://waarneming.nl/foto/view/3121515 - they are rather obvious, perhaps slightly less obvious than on the subject one but otherwise rather similar. Structurally, the seemingly long primary projection and blackish tertial markings and coverts indicate to my eyes michahellis...but can´t exclude herring ;)

JanJ

Re: Head-streaked michahellis or Azorean atlantis?

Posted: Thu Apr 11, 2013 7:38 am
by lou bertalan
adriaens wrote:To be honest I am not even sure that this bird is a 2nd winter; note the distinct white primary spots, which seem to indicate 3rd winter.
I am also not sure that it is not a Herring Gull...
tertial and gc pattern is indeed odd for michahellis and i was wondering along the same lines as peter if this isn't in fact a 4cy herring gull...

Re: Head-streaked michahellis or Azorean atlantis?

Posted: Thu Apr 11, 2013 2:36 pm
by richard lowe
Peter, Jan and Lou - I attach another image showing a 3w type Herring Gull for comparison of upperpart tones. The subject bird (i.e. headstreaked 'michahellis') is darker toned / less blue and this combined with the black tertial marks, covert marks, red eye ring, strongly suggested 'michahellis' to me. However, I accept that a 4cy Herring Gull could look like this. The purpose of the post was the degree of head streaking at this time of the year - I apologise if the ageing / species i.d. has got in the way!
Regards, Richard Lowe.

Re: Head-streaked michahellis or Azorean atlantis?

Posted: Mon Jun 10, 2013 1:08 pm
by Stefan
As an input into this discussion, I forward a link viewtopic.php?f=13&t=759
where I show photos of 3 herring gulls with unusually dark head streaking in Iceland.

Best regards

Stefán

Re: Head-streaked michahellis or Azorean atlantis?

Posted: Tue Jun 11, 2013 4:23 pm
by marsmuusse
Well one thing is sure, on Iceland when they say head streaking they really mean head streaking.