Evan, if you have a copy take a look at the photo on the front of Wingspan,
Vol 15, No1, March 2005. It is an immature Spotted Harrier and has a blotchy
white band across the rump, and obvious facial disk. There is material on
raptor id by Steve Debus in that edition as well. In his book "The Birds of
Prey of Aus" Steve also describes Spotted as having a slight wedge shape to
the tail which can appear dished from behind compared with a more gently
rounded to square tip of the Swampy; and that is also evident in the photo
mentioned above. I am not sure if those features are always obvious though.
Greg Czechura, Qld Museum, a frequent co-author with Steve did run a great
one day course on raptor id which shows how you can use comparative features
such as different wing shapes; tail shapes; and tail length compared to wing
base width to confirm ids. I'm not sure if he still does the course or would
provide material but I have found that his methods have really worked for me
on numerous occasions.
Regards Rex Fisher
-----Original Message-----
From:
On Behalf Of Evan Beaver
Sent: Friday, 24 November 2006 7:35 AM
To: Birding-Aus
Subject: Pitt Town Harrier
Birders,
I mentioned a Harrier I saw yesterday at Pitt Town, which after some
consternation we decided was a SwampHarrier. This was decided on the
basis of information supplied in Pizzey, Simpson+Day and Moorecombe.
The main identifying feature was the pale rump; I didn't think it was
white as such and not the shape I'm used to seeing, more a thin pale
band than the bold white of a Swampy. Now, consultation with Debus has
swung me back toward a Spotted.
Debus's approach has changed my identifying procedures for Raptors.
He suggests that like waders, plumage in raptors can be misleading and
that the overall shape and behaviour are much more useful. So this
bird was no different. It seemed a broad winged bird to me, narrower
at the body, gliding in a very deep dihedral, carpals held fairly
straight. It quartered low over the lagoon, using the grasses as
cover, with virtually no wong movement. Size was very similar to the
Brahminies I had seen in Cairns the week before. Underbody colour was
a bold rusty brown streaked with small white lines down the front. The
facial disc was clearly visible in the horizontal afternoon light. I
watched it pass low over the waterbirds which didn't seem phased, and
then land in the long grass over the back. I actually managed to get
the scope onto it in flight and saw dark grey uperparts and that thin
white rump patch.
To confuse matters, another harrier flew over later in the day. This
was a clear Swampy; the rump marking a bold white, at least 25.4mm
across. Colouring was more uniform above and below, and the facial
disc not obvious.
To summarize: There are 2 Harriers at Pitt Town, one of them might be
a Spotted. Keep your eyes peeled if you go there. I currently lack the
courage of my convictions to tick it but I'll be back there very soon
hoping for a better look.
Evan
--
Evan Beaver
Lapstone, Blue Mountains, NSW
lat=-33.77, lon=150.64
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