Hi Niven,
Indeed the photo of on p. 471 of the Seabirds NPIAW (Lindsey 1986) is a
Great Frigatebird, not a Least as labelled. It is a female most likely in
its third year (second basic plumage). Females in second year (first basic)
have a more rounded belly patch with traces of black mottling around the
vent where this bird has a big black intrusion from the vent making a
U-shape in the rear of the belly patch. The pale, untidy mottling around
the head and throat are the last traces of immaturity.
You are correct that Least shows white axillary spurs in ALL plumages.
However, about a third of 1st year (juvenile) and 2nd year Greats also have
white axillary spurs (see p. 465 of NPIAW and photos 395 and 396 in
Harrisson 1987), which is perhaps the biggest ID pitfall for these 2
species. Least show more black on the throat in all plumages except
juvenile and the early stages of second year (first basic).
Happily and surprisingly, p. 471 appears to be the only misidentified
frigatebird photo in NPIAW. However, there's something funny about the
photo on p. 469. Even when you turn it up the right way its a terrible
photo. Harrison's Frigatebirds are all correctly labbelled as far as I can
tell. There are no photos of Least in Enticott & Tippling 1997
(Photographic Handbook of the Seabirds of the World; Hamliyn). The four
photos labelled Lesser, and all from Lady Elliot Island on the GBR, are
actually all Greaters. The last of these is even mis-sexed.
A word of warning: stay away from Harrison 1983 (Seabirds an Identification
Guide) for frigatebirds; it's a complete disaster, bearing little
resemblance to reality.
cheers
At 17:04 3/03/01 +1000, you wrote:
-----Original Message-----
From: Niven <>
To: <>
Date: Saturday, 3 March 2001 11:40
Subject: [BIRDING-AUS] Frigatebird ID
G'day everyone
I've been going over the points of separation between the
Frigatebirds we get (or are likely to get) and am a bit puzzled about
one thing. I'd assumed that Least showed the white bar on the
underwing in all plumages (I hadn't noticed any lacking this in my
observations, and the field guides show this) yet there is a photo in
the National Photographic Index (Seabirds, p.471) showing neat
plumage but no white 'armpit bar'. This bird also lacks a dark
throat, which I'd expect to be present in a Lesser Frigatebird at the
age this one looks. Is this a misidentified/mislabeled bird in the
photo (ie, is it Great Frigatebird) or are these two species harder to
tell apart than I thought?
Harrison's photographic guide shows a few photos of
immature/juvenile Lesser Frigatebirds all with the white line on the
underwing, and attaining the dark throat prior to adulthood.
Any comments/suggestions?
They're not that easy, Frigate (birds)
Niven
Refs:
Lindsey, T.R., 1986, The Seabirds of Australia, Angus & Robertson
Harrison, P, 1987, Seabirds of the World - A Photographic Guide,
Croom Helm.
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