----- Forwarded Message ----
From: Brian Finch <birdfinch@gmail.com>
To: Itai Shanni <itaisha1@yahoo.com>
Sent: Sun, 21 March, 2010 16:33:37
Subject: unidentified phylloscopus nairobi np
Dear Itai,
I found this bird in Nairobi Park yesterday. I was wondering if you
could give me your ten cents worth as to what you think it could be, I
have my ideas! Can you put it on the net, or send to anyone else who
might have experience with northern phylloscs. Looking forward to
hearing of your trip, I bet I would have had stacks of liers. I have
posted latest observations separately,
Hope you are all well,
Brian
“Can
anybody shed any light on this observation please. I am somewhat
confused as to the identification of a phylloscopus in Nairobi
National Park on 20th March 2010. I have an idea of what it might be,
but it is rather outrageous though not impossible.
I was with Patrick Lhoir and his father, we were at the Hippo Pools
and there were a few migrant warblers in the area. In the canopy of a
medium-sized acacia we located a rather chunky Phylloscopus but it was
difficult to judge size without any other birds for a direct
comparison, however it looked larger than any Willow Warbler we had
been looking at (including one minute prior to the observation and a
minute after it). I could see through the vegetation that the bird was
pure white underneath and said that it must be a Wood Warbler. As the
bird emerged from cover we could see that the bird lacked any yellow
on the throat and breast and this too was snow white. Knowing
that
there have been Wood Warblers that lack the yellow I still thought
that this bird could only be a Wood Warbler. We took video and images
of the bird, but clearly the tail is too long for a Wood, being more
similarly proportioned to a Willow.
Examination of the images shows some other features, not associated
with migrant phylloscopus to the region. The most noticeable feature
apart from the all white underparts was the striking head pattern. The
upper parts were not seen well as for most of the time the bird was
almost directly overhead, but appeared a fairly bright olive-green,
brighter than most Willow Warblers that we encounter here and darker
than Wood Warbler. The top of the head was also olive-green. Under
this was a very pale yellow sweeping supercilium extending from the
base of the bill back to near the start of the nape. An equally long
and striking dark line ran from the back of the eye, as far
as the
sides of the nape, whilst in front of the eye this continued to the
base of the bill with a more greenish tinge. As a continuous line this
ran underneath the white supercilium for its entire length. Underneath
the black supercilium was a shorter whitish line running from just
under the leading edge of the eye, back to the side of the nape, and
below this a shadowy crescentic line of similar length. The bill was
dark on the ridge of the upper mandible, paler brown on the sides and
lower mandible with a yellowish base and dark tip. The underside of
the lower mandible was brighter yellow as was the mouth lining,
however the bill appeared black against backlight. The bill appeared
shorter than Willow Warbler. The eye was brownish, but appeared dark
in the field. There was a narrow pale crescent below the lower eyelid.
The underparts from chin to extremity of undertail coverts were pure
white, but although not
noted in the field, the image close-ups show
faint and diffuse longitudinal darker streaking. The undertail coverts
were long, but there was still substantial amount of tail protruding
unlike a Wood Warbler. The legs were pale pinkish-flesh, possibly
slightly paler than a Willow Warbler. The images show a whitish
translucency all around the extremities of the tail which was quite
deeply notched.. The bend of the wing looks yellow and in one image a
slightly raised wing shows the underwing as appearing lemon-yellow.
The movements through the vegetation were quite sluggish, there was no
noticeable tail or wing flicking, and the bird gleaned from the acacia
twigs. After we had studied this bird for several minutes it flew off
but did not seem to go any great distance.
The upper images are grabs from the video to show different features,
the remainder a selection of images.”