James sent me this Marsh Harier with a suggestion of a possible Eastern Marsh (spilonotus). I cant get past a female Western, with a perhaps paler hand than normal. What do others think? The subject harrier is surrounded bt a young female (dark iris) spilonotus.
I am sending you a message emailed to friends earlier today regarding a marsh harrier at sheppey, kent, uk, which shows some features of eastern. the photos are on http://www.pbase.com/james_lowen/circusas I cannot work out how to attach here. My email is lowen.james at gmail. com if you want to join the email discussion
Durwyn Liley and I had an odd Marsh Harrier at Sheppey on Thurs pm.
The bird was on the Harty Ferry road, in the main raptor area, halfway
between the channel and the Capel Fleet RSPB raptor view point. I
think the time was c15h (the EXIF data on the photos shows midday, as
clock is set to Argentina time).
Durs picked up the bird and called me to have a look at this 'odd
marsh harrier' quartering c 150m away, with loads of cream on it. i
wondered aloud as to what eastern marsh looked like (i've seen it in
Thailand, according to my notebook, but can't remember anything about
it) and turned back to the car to get camera and rattle off some
distant record shots. the bird then drifted off east. we thought no
more about it and bumbled on.
looking at the photos on thurs night, i began to get a bit worried, so
checked a couple of photos of eastern marsh harrier (EMH) on the web.
the similarity was uncanny. couldn't do anything about it fri, other
than forwarding the photos to dave gandy out in Bangkok (who has
shared them today with phil round). but this morning i've had a bit
more time to look into possibilities.
I attach a series of photos of the bird, all low res, plus one
composite image for ease of reference ('ecomposite.jpg). I also attach
a composite image with the bird in the centre surrounded by images of
EMH, largely taken from Oriental Birding Images
The most striking feature of the Sheppey bird is the extensive whitish
bases to the underprimaries, which contrast with dark secondaries and
restricted black primary tips. Judging from Robson, Fergusson-Lees,
and Brazil, this is a classic feature of juv EMH. I have not been able
to find a single photo of female/juv western marsh harrier (WMH) on
the web with such pale underprimaries and such restricted black
The Sheppey bird also shows an extensive cream breast band, apparently
extending onto the neck. While second calendar-year female WMH can
show this feature, neither Durs nor I had ever seen such an extensive
band, and the apparent extension onto the neck is suggestive of EMH,
according to Niall Moores in a v useful Birds Korea web article
I only got one shot of the Sheppey bird's upperparts, but the
extensive cream on the forewing coverts is striking - and more than I
can ever remember seeing on a WMH. Intriguingly there are hints of
pale tips to the greater coverts (forming a very narrow line); while
juv WMH show this, older females apparently do not, whereas it is
routine on juv EMH. Its very presence suggests that the bird is a
juvenile. If it is, there is far too much cream for WMH, so EMH looks
a live possibility. There is also the vaguest hint of pale feathering
on the rump - which again would be a feature of EMH. Juv EMH's often
show a faintly barred tail, but the photo is too poor to enable me to
judge either way whether this feature is present or absent.
The Birds Korea article suggests that head pattern is critical to
distinguish adult/subadult female WMH from juv EMH. Here the photos
are equivocal - but erring towards WMH. There is clearly a dark 'mask'
behind the eye on the ear coverts, which is more likely on WMH.
However, the photo of the upperparts appears to show a cream
demarcation between eye mask and dark neck, which brings EMH back into
play (if the eye mask was continguous with the dark neck, Birds Korea
article suggests that it would mean WMH). I cannot determine, from
photos whether the eye mask extends onto the lores; if it did, this
would again indicate WMH.
I keep coming back to those underprimaries. On the claim of a bird in
Sweden last Sep (a 3rd calendar year bird), web commenters drew
attention to this feature:
http://surfbirds.com/forum/showthread.php?p=17728. If anyone can find
me photos of female WMH with such extensive pale underprimaries, I'd
be v happy to see them! Finally, I am aware that EMH and WMH
hybridise, but have no feel for what features hybrids might show.
Another complication! At the very least, as Dave G suggested to me
this morning, there might be merit in putting out a cautionary note on
Grateful for any advice you guys can give. Feel free to forward the
email more widely (I will try to send to folk such as Jan Jorgensen,
Brian Small, Alan Lewis and Rich Bonser via Birdforum, Surfbirds
forums and Facebook - but feel free to email them if you know them).
And - Andy and John in particular - you might want to alert Sheppey
regulars, or even get over there yourself. Better photos, particularly
of the head pattern, are a must!