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ID-FRONTIERS for July 7-13, 2002
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Subject: Nashville Warbler ID
From: Eric Preston <eric(AT)ERICWPRESTON.COM>
Date: 8 Jul 2002 7:42am
This is a multi-part message in MIME format.
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Dr. Earl S. (Mick) McHugh asked me to post this for him, as he's not on ID
Frontiers...
Possibility of "western" Nashville Warblers in Kansas City area?
I have observed, in three cases in the last two years, Nashville
Warblers (Vermivora ruficapilla), that have constantly "bobbed"
their tails in the manner of Prairie Warblers (Dendroica discolor).
All of these birds have been seen within fifty miles of Kansas
City, Missouri.
The western sub-species V.r.ridgwayi is noted as frequently
bobbing their tail, versus "rarely, if ever bobbed in nominate
"ruficapilla" (pp.171 in "Warblers" by Dunn/Garrett).
All of the above mentioned Nashville's appeared to be adult,
Two in May 01 and 02, and one Sept. of 01. the fall bird did
appear to have "more" white in the belly-vent area, but in all
cases, back and rump color were subjective, and non-comparable
to other Nashville's. All three were seen well, and the tail bobbing
was consistent for the duration of all three sightings.
Because I am "auditorially challenged", no song or call notes
were heard.
What are your thoughts about the possibility of these sightings
being the western sub-species "ridgwayi"?
My thanks to Eric Preston for putting this question on-line.
Mick McHugh
Kansas City
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Subject: Identifying Black and Brown Noddies
From: Martin Reid <upupa(AT)AIRMAIL.NET>
Date: 9 Jul 2002 5:37am
Dear all,
When a BLNO is in with some BRNOs it looks obvious, yet a lone bird with no
size clues can be much harder to assess (especially if the crown pattern
and bill shape seem somewhat intermediate.) I'd like to get some input on
the following tentative ID feature; I'm sure it is nothing new, yet I can't
find it discussed in my references:
The feature concerns the exact shape and position of the whitish lower eye
crescent, and for the purpose of explaining this, you need to imagine the
eye being divided into four equal quadrants along the 12,3,6, and 9 O'Clock
lines, starting at the center of the pupil. The lower-rear quadrant (3 - 6
O'Clock) is the critical zone, and its upper/rear boundary and lower/front
boundary are what are referred-to in the following analysis:-
On BRNO the upper/rear start-point of the crescent is at or very slightly
above the 3 O'clock point; the opposite end is always beyond the 6 O'Clock
point, such that there is always an upwards-curl to this end of the
crescent. It is a bit variable, but a slight upwards curl is always visible.
On BLNO the upper-rear start-point seems to be at or just a fraction below
the 3 O'Clock point - this is very hard to quantify, yet, to my eye,
visible at good angles. To express this another way, the dark gap between
the upper-rear edge of the lower eye-crescent and the rear of the upper
eye-crescent is clearly larger in BLNO compared to BRNO. The upper eye
crescent also seems to be consistently shorter on BLNO, such that this
upper crescent - when visible - is always clearly smaller than the dark gap
between it and the start of the lower eye-crescent (the opposite for
BRNO). The opposite end (lower/front) of the lower eye-crescent either
ends right at the 6 O'Clock line, or extents just beyond it BUT ANGLES AWAY
FROM THE EYE slightly, so that there is never any upwards curl at this end
of the crescent.
All this may seem esoteric, but in combination it creates a distinctive
pattern, I feel. After looking at many images, I found 20+ BRNOs and 16
BLNO images that fitted the above pattern, with no birds that broke this
"rule". I did find a few images where it was not clearly determinable, and
at least two where the ID of the photographed bird is questionable/wrong.
Here is an online image with both species:
http://www.duke.edu/~jsr6/BLNO.jpg - you need to copy/paste/enlarge this
image to see the differences.
- plus look at photo 207 ( last page) in the TERNS book by Malling Olsen
and Larsson.
One problem in assessing this feature is that when the head is turned
towards the viewer, the bare skin of the eye-ring (not the eye-crescent,
which is feathering) can reflect the light somewhat, creating a false
impression of where the crescent ends.
My experience is limited to looking at photos of these birds, plus one
fly-by BRNO, so I don't have much to go on, yet my analysis of images looks
promising. Interestingly, David Sibley, in his Field Guide, has illustrated
this feature perfectly, yet does not mention it in the text.
A question regarding these taxa: most guide books quote overall
measurements ("length") without stating how these measurements were
obtained; Were most of these based on laid-out skins? - and most
importantly, can BRNO size variation extend to the point where some are
almost as small as the average for BLNO???
Regards,
Martin
Martin Reid
Fort Worth, Texas
upupa(AT)airmail.net
http://www.martinreid.com
[ << | >> | ^^ ]
Subject: Short-legged "mystery tern"
From: Floyd Hayes <floyd_hayes(AT)HOTMAIL.COM>
Date: 9 Jul 2002 10:28am
Photographs of a short-legged "mystery tern" are posted at:
http://www.geocities.com/secaribbirds/ttmysterytern3
Actually its identity isn't really a mystery but the implications for
misidentification are obvious.
Floyd E. Hayes
Lecturer in Zoology
**********************************************************
Department of Life Sciences, University of the West Indies
St. Augustine, Trinidad and Tobago
Tel: 868-645-3233 x2206, Fax: 868-663-5241
Website: http://www.geocities.com/floyd_hayes
**********************************************************
_________________________________________________________________
Chat with friends online, try MSN Messenger: http://messenger.msn.com
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Subject: Plegadis identification and aging
From: Angus Wilson <wilsoa02(AT)ENDEAVOR.MED.NYU.EDU>
Date: 9 Jul 2002 1:37pm
During the past week, two different White-faced Ibis were discovered on the
south
shore of Long Island, New York. Glossy Ibis are abundant during the summer but
White-faced Ibis
is a less than annual rarity. I have posted some photos of these birds on Ocean
Wanderers.
http://www.oceanwanderers.com/NY.WFIbis.html
Andy Guthrie, has also posted some excellent shots of the Cow Meadow ibis,
which
he first found on the 4th July.
http://home.earthlink.net/~andyguthrie/wfibis.htm
A question for ID-Frontiers, is what age are these birds? Both lack the
prominent
white feathering bordering the naked facial skin and have extensive pale brown
flecking on the head
and upper neck. Although a large number of young Glossy Ibis have just fledged,
most adults are still in what seems like full breeding plumage. How rapidly do
white-faced ibis loose
the white feathering? Maybe observers to the west of us can comment on the
current state of local birds?
Cheers, Angus Wilson
New York City
http://www.oceanwanderers.com
-------------------------------------------------
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Subject: From Peter Pyle: Aging and molt in White-faced
Ibis
From: Angus Wilson <wilsoa02(AT)ENDEAVOR.MED.NYU.EDU>
Date: 9 Jul 2002 6:55pm
Peter Pyle asked me to forward this to the list. As usual, Peters comments are
insightful and rich in unpublished information. Angus Wilson
******************************
Hi all -
I have recently looked through over 100 White-faced Ibis specimens at
California Academy of Sciences to determine molts and plumages. Based on this
examination I would age the Cow Meadow bird as either a typical(?)2 year-old
(TY) or a somewhat retarded 3 year-old (4Y), less likely a retarded 4 year-old
(5Y), and the Jamaica Bay bird as at least a 3 year-old(ATY) and possibly at
least a 4 year-old (A4Y).
Plegadis appear to have one protracted partial "first prebasic" molt that spans
from August through March or April of the second year, followed by a complete
second prebasic molt in May-Nov, essentially followed by the definitive cycle
consisting of a partial prealternate molt in Jan-Mar and a complete prebasic
molt in Jul-Nov. The white feathering of the head and neck is not present on
all juveniles (~40% of specimens in juvenal plumage lacked white). I went in
predicting that these were just downy tips remaining on the juvenal
feathers(that wear off by December) but this was not the case: they are pure
white juvenal feathers which appear to be replaced early during the first molt,
by Nov-Dec. Other features of juvenal plumage include brown head and neck
(lacking white streaks typical of adult basic plumage), dull greenish-brown
lesser and median coverts, and a dull brownish-green tail.
The first molt includes most or all body feathers, no to a few lesser and
median coverts, and no greater coverts or flight feathers. In SYs the head and
neck remains largely unstreaked and the lesser and median coverts remain mostly
to entirely dull greenish brown, with a few maroon centers to replaced feathers
on some birds. They do not acquire the fully bright maroon lesser coverts or
shiny median coverts displayed by the New York birds.
TYs are variable. The rects are squared and have a purplish gloss, quite
different from the rounded and dull greenish-brown juvenal rects retained by
SYs. The head and neck can consist mostly to entirely of adult-basic like
plumage (brown with white streaks) or it can show a variable amount(to all?) of
maroon alternate plumage. The lesser-covert patch is partially acquired (mixed
maroon and greenish feathering - I estimated 20-85% of "full" adult alternate
plumage) and the glossy sheen to the median coverts of adult-alternate plumage
is mostly to entirely acquired. The Cow Meadow bird could be a somewhat
advanced individual in this plumage whereas the Jamaica Bay bird (in "full"
alternate lesser-covert plumage) is too far advanced to be a TY and thus an ATY
at least.
Although I knew the precise age on none of the specimens, I predicted(based on
the easier-to-study plumages in White Ibis) that some but not all 4Ys will show
less than "full" alternate plumage, and the Cow Meadow bird could be one of
these. The lesser-covert patch may be on the full side for a TY (~80% "full"
adult alternate) but my sample of spring TYs was small. Defining criteria for
the separation of TYs and 4Ys (and even retarded 5Ys?) will require study of
marked, known-age birds.
I have not looked at this in Glossy Ibis yet but would predict the wing-covert
criteria (at least) to be similar. I noticed on the photos of the New York ATY
Glossy Ibises that the breast and belly appear to be in full alternate plumage
whereas adult-alternate White-faced Ibis usually retained a few basic breast
feathers and many to all basic belly feathers.
This suggests that the prealternate molts of Glossy Ibis may be more complete
than those of White-faced Ibis but whether or not this carries over to the
first "prebasic" molt or 2nd prealternate molts (and plumages)remains to be
seen.
Peter Pyle
-------------------------------------------------
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Subject: Red-tail Question
From: "Guenther, Michael E." <GUENTHME(AT)TUHS.TEMPLE.EDU>
Date: 10 Jul 2002 7:16am
I realize this is not an "ID" question but I thought that someone out there
may be able to help.
Have there ever been sightings of the "krider's" Red-tailed Hawk in the
northeast or mid-atlantic areas?
And...what is the range of the Krider's form?
Michael Guenther
Delaware County, Pennsylvania
[ << | >> | ^^ ]
Subject: Re: Red-tail Question
From: Michel Bertrand <bertrmi(AT)COLBA.NET>
Date: 10 Jul 2002 8:33am
Michael E. Guenther asked :
> Have there ever been sightings of the "krider's" Red-tailed
> Hawk in the northeast or mid-atlantic areas?
___________________________
Hi,
I did see one in southern Québec, near Ormstown, a few years ago. The bird
was perched when I noticed it along the road as I was conducting a field
trip. It was so pale that, for a second, while driving, I suspected a
Gyrfalcon. But I saw it was a buteo. We stopped and observed it for a long
time through our scopes. The buteo had an mainly white head, only very faint
lines on the lower part of its breast and only the distal part of its tail
was showing some rufous, but a very pale rufous. The proximal third of the
tail was almost white. I have seen similar birds in western Manitoba. Here,
I have seen other pale Red-tailed Hawks, but never one showing all the
characteristics of the krideri as this bird was.
A probable krideri is reported now in Québec, at Candiac near Montréal. See
the original message by Jean-Guy Papineau at
http://birdingonthe.net/mailinglists/ORNQ.html#1026179526
Be happy...
MICHEL BERTRAND
Sainte-Julie, Qc
bertrmi(AT)colba.net
[ << | >> | ^^ ]
Subject: Cayenne Tern
From: Floyd Hayes <floyd_hayes(AT)HOTMAIL.COM>
Date: 11 Jul 2002 8:45am
Nine superb photos of Cayenne Terns nesting in Argentina, kindly supplied by
Argentinian seabird researcher Flavio Quintana, are posted at:
http://www.geocities.com/secaribbirds/idcayennetern
Dowloading the photos will take some time. If you have difficulty accessing
the page due to data transfer limitations, try again later.
The Argentinian birds look very similar to what I often see here in Trinidad
and Tobago--and are unlikely to be confused with Elegant Tern, though Flavio
wrote "I saw few individuals with bright orange bills but unfortunately we
don't have any pictures."
-Floyd
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