 |
|
|
|
|
ID-FRONTIERS for July 8-14, 2001
[ Prev Week
| Next Week
| Calendar Month
| ID-FRONTIERS Info
]
|
|
To use email addresses replace '(AT)' with '@'.
This is done to confuse the spam 'bots.
|
[ << | >> | ^^ ]
Subject: Eastern smithsonianus
From: Peter Pyle <ppyle(AT)PRBO.ORG>
Date: 8 Jul 2001 9:28am
I just read the interesting article by Jonsson and Mactavish in Birders
Journal (10:92-107, 2001) documenting that adult Herring Gulls in winter
at Niagara Falls have smaller mirrors on p9 and/or p10 than adult
Herring Gulls in Newfoundland. The authors speculate that these two
populations might represent different subspecies.
I was wondering if the plumage variation might also be explained by
sex-specific differences in wintering areas; i.e., Niagara birds may
consist mostly of females whereas Newfoundland birds may be
predominately males. Larry Spear (Auk 105:128-141) found that adult male
Western Gulls from the Farallon Island population remained in central
California (closer to the breeding grounds) during the non-breeding
season, whereas females dispersed to northern and southern California,
apparently unable to compete for food with the larger males. The bill
size and head shapes in the photos of the Niagara birds remind me of
females whereas those of the Newfoundland birds remind me of males;
perhaps a sex-specific dispersal pattern is also occurring in these
Herring Gulls.
The size of the mirrors in p9 and p10 of gulls is known to vary with
age. Does anyone know if this might vary with sex as well? I have
recently videotaped the wings of ~400 known-age and known-sex Farallon
Western Gulls to investigate this but I won't have time to analyze the
tapes until fall.
Peter Pyle
[ << | >> | ^^ ]
Subject: Re: Spruce Grouse booming
From: Lang Elliott <lang(AT)NATURESOUND.COM>
Date: 8 Jul 2001 11:33am
Dear ID Folks:
I actually started this inquiry about Spruce Grouse booming with a posting
last week on a nature recordists listserve.
Several years ago, I recorded Spruce Grouse in Riding Mountain National Park
in Manitoba, where I concentrated on their wing fluttering display given
during short flights, plus various other sounds made with wings and feathers
while perched on limbs or on the ground. Samples of these recordings are
included in my "Stokes Field Guide to Bird Songs, Eastern".
At no time did I hear anything comparable to the booming or hooting of Blue
Grouse, even though I closely monitored the low end freequency spectrum
using headphones. However, I did discover that I could hear a number of
neighboring birds giving flight displays, and the grouse seemed to actually
respond to one another in this respect, leading me to believe that they hear
each other's flight displays (note that I could not hear the displays of
neighbors without using headphones and amplification).
Some ornithologist-birders actually believe that male Spruce Grouse
congregate in "loose leks" in evergeen stands and coordinate their breeding
behavior to some degree . . . my observations in Manitoba lead me to agree.
I was first told of this by birder and tour-leader Daniel Weedon, who lives
just south of Riding Mountain park. But this has nothing to do with booming
or hooting.
It is my feeling that Boag & Shroeder (1992, Birds of North American no.5)
and Hjorth (1970, Viltrevy 7: 183-596) are correct in their assertion that
the recording analysed by Crawford Greenewalt (1968, Bird song: acoustics
and physiology) was probably mis-identified. I would not be surprised if
this is the same recording included in the Peterson guide (A Field Guide to
Western Bird Songs).
Given our current knowledge of this subject, I feel that we should assume
that Spruce Grouse do not boom like Blue Grouse, until proven otherwise by
modern recordings and accurate observations.
Lang
Lang Elliott
NatureSound Studio
www.naturesound.com
[ << | >> | ^^ ]
Subject: Re: Eastern smithsonianus
From: "Lethaby, Nick" <nlethaby(AT)TI.COM>
Date: 8 Jul 2001 12:18pm
This message is in MIME format. Since your mail reader does not understand
this format, some or all of this message may not be legible.
----INCLUDING text/plain MIME SECTION----
There is a difference in mirror patterns between the pacific wintering
populations of smithsonianus and that of Eastern (at least Atlantic) birds.
Basically W birds tend to show just one mirror (sometimes with small second)
whether E birds have two. The Niagara birds may be somewhere in between or
it could, as Pete Pyle suggests, be a sexual difference.
-----Original Message-----
From: Peter Pyle [mailto:ppyle(AT)PRBO.ORG]
Sent: Sunday, July 08, 2001 9:31 AM
To: BIRDWG01(AT)listserv.arizona.edu
Subject: [BIRDWG01] Eastern smithsonianus
I just read the interesting article by Jonsson and Mactavish in Birders
Journal (10:92-107, 2001) documenting that adult Herring Gulls in winter
at Niagara Falls have smaller mirrors on p9 and/or p10 than adult
Herring Gulls in Newfoundland. The authors speculate that these two
populations might represent different subspecies.
I was wondering if the plumage variation might also be explained by
sex-specific differences in wintering areas; i.e., Niagara birds may
consist mostly of females whereas Newfoundland birds may be
predominately males. Larry Spear (Auk 105:128-141) found that adult male
Western Gulls from the Farallon Island population remained in central
California (closer to the breeding grounds) during the non-breeding
season, whereas females dispersed to northern and southern California,
apparently unable to compete for food with the larger males. The bill
size and head shapes in the photos of the Niagara birds remind me of
females whereas those of the Newfoundland birds remind me of males;
perhaps a sex-specific dispersal pattern is also occurring in these
Herring Gulls.
The size of the mirrors in p9 and p10 of gulls is known to vary with
age. Does anyone know if this might vary with sex as well? I have
recently videotaped the wings of ~400 known-age and known-sex Farallon
Western Gulls to investigate this but I won't have time to analyze the
tapes until fall.
Peter Pyle
----DELETED text/html MIME SECTION----
[ << | >> | ^^ ]
Subject: Re: Spruce Grouse booming
From: KACastelein and DJLauten <birdsong(AT)HARBORSIDE.COM>
Date: 8 Jul 2001 1:32pm
Lang Elliott wrote:
> At no time did I hear anything comparable to the booming or hooting of Blue
> Grouse, even though I closely monitored the low end freequency spectrum
> using headphones. However, I did discover that I could hear a number of
> neighboring birds giving flight displays, and the grouse seemed to actually
> respond to one another in this respect, leading me to believe that they hear
> each other's flight displays (note that I could not hear the displays of
> neighbors without using headphones and amplification).
>
> Some ornithologist-birders actually believe that male Spruce Grouse
> congregate in "loose leks" in evergeen stands and coordinate their breeding
> behavior to some degree . . . my observations in Manitoba lead me to agree.
> I was first told of this by birder and tour-leader Daniel Weedon, who lives
> just south of Riding Mountain park. But this has nothing to do with booming
> or hooting.
>
> Lang
>
Lang, others,
When I did my graduate work on Ruffed Grouse I came to a similar
conclusion - that like most grouse, Ruffed Grouse are too somewhat of a
lek species. We tend to think of true leks as places where male grouse
(or other species) tend to display together and females choose the best.
I came to believe that Ruffed Grouse are doing what I called an
"audible" or sound lek. Visual display is not as important for these
forest birds, but audible display is. The males often would clump
together unevenly in the habitat, always within earshot of each other.
They would respond to each other drumming. The clumping could be
explained by microhabitat selection, but in some places where we worked
- even though we did not try to collect data to prove this - it seemed
there was enough habitat all around, but yet the males were often
clumped in areas. I believe the drumming was very similar to Prairie
Grouse visual displays, except the females need not see the male
drumming, but could choose a male from the sound of his drum. All the
males would have to be pretty close together so that all the females
could hear all the males and choose the best one. Essentially that is a
lek, just not a visual one. It would not surprise me to find Spruce
Grouse doing the same. By the way, the uneven distribution of Ruffed
Grouse on the landscape is most dramatic at the low point of their ten
year population cycle. When there are lots of grouse around, the males
spread out, but when numbers got real low, the few remaining males would
often be pretty close to each other.
Dave Lauten
Bandon OR
birdsong(AT)harborside.com
[ << | >> | ^^ ]
Subject: Re: Eastern smithsonianus
From: Phil Pickering <philliplc(AT)HARBORSIDE.COM>
Date: 8 Jul 2001 7:19pm
Peter and all,
As a possible parallel and for whatever it's worth, I've also noticed a
correlation between size, and amount and lateral extent of the black in the
wingtips of adult thayeri that winter on the Oregon coast. Larger birds (and
perhaps those more male-like structurally) seem to tend to have more black,
and to be more filled in on the wingtips. More petite birds most often seem
to show less black and to look more obviously patterned. I've posted about
this in the past trying to figure out if this might not be a sign of advanced
population-wide introgression with glaucoides. Perhaps it's actually part
or all male/female variation?
Phil Pickering
Lincoln City, Oregon
philliplc(AT)harboriside.com
>The size of the mirrors in p9 and p10 of gulls is known to vary with
>age. Does anyone know if this might vary with sex as well? I have
>recently videotaped the wings of ~400 known-age and known-sex Farallon
>Western Gulls to investigate this but I won't have time to analyze the
>tapes until fall.
>
>Peter Pyle
[ << | >> | ^^ ]
Subject: Mystery Raptor
From: Trevor Hardaker <trevor(AT)DHK.CO.ZA>
Date: 11 Jul 2001 1:02am
Greetings from Cape Town,
How well do you know your raptors? Have a look at the latest mystery bird,
an interesting young raptor, on our website at http://www.zestforbirds.co.za
and let us know what you think it is and what your reasons are for saying
so.
Looking forward to hearing from you.
Kind Regards
Trevor and John
---------------------------------------------------------
Trevor Hardaker and John Graham
Cape Town, South Africa
ZEST for BIRDS
Website: http://www.zestforbirds.co.za
---------------------------------------------------------
[ << | >> | ^^ ]
Subject: RFI: someone doing DNA work on gulls?
From: Martin Reid <upupa(AT)AIRMAIL.NET>
Date: 11 Jul 2001 5:32am
Dear all,
My apologies for this rather off-topic email, but the end-results may well
be of interest to ID-ing gulls in the Americas.
I have obtained a photo of the spread wing of a dead adult gull from Oman
that seems to match my idea of a "Big Pale Heuglini" - see
http://www.martinreid.com/heuginx.html and some of its pages for more on
this form. I have also been sent the outer two primaries of this
individual, thus I want to get in touch with any researcher who may be able
to use this tissue sample in a meaningful way, with regard to this
individual's relationships with other known taxa.
Thanks in advance for any leads,
Martin
Martin Reid
Fort Worth, Texas
upupa(AT)airmail.net
http://www.martinreid.com or http://www.cyberramp.net/~upupa
[ << | >> | ^^ ]
Subject: Data on Banded HERG in Texas
From: Martin Reid <upupa(AT)AIRMAIL.NET>
Date: 11 Jul 2001 6:20am
Dear all,
Briefly continuing the unseasonal gull theme, I have obtained the banding
data for the adult HERG seen near Galveston in early April 2000:
http://www.martinreid.com/hsmitp59.html
- The bird was banded at an arctic field camp at East Bay, Southampton
Island in Hudson Bay, Nunavut, Canada (61.4 N, 84.0 W) on June 21, 1998. A
few interesting observations about this gull at the East Bay field site
from the researcher:
"R4 was captured on June 21, 1998 (sadly its plumage status was only
recorded as immature, suggesting alternate III). It did not breed in 1998.
R4 returned to the Island colony in 1999 in definitive alternate plumage
but did not breed. R4 foraged in the territories of others as a "floater".
Your observation: La Marque, Texas: April 3, 2000
Arrival date East Bay, Southampton Island: May 30, 2000
In 2000, male R4 and female H3 successfully took possession of a nest site
and territory from unpaired "No Code", occupied the site for a short period
of time until R4 lost a battle for the site with a paired unbanded male.
The R4 and H3 pair subsequently dissolved and R4 reverted to the strategy
of not breeding and "floating" around the colony, intruding into the
territories of others to steal eggs, as it had done in previous years. "No
Code" had also adopted this "floater" strategy. R4 and "No Code"
consequently both failed to breed."
Regards,
Martin
Martin Reid
Fort Worth, Texas
upupa(AT)airmail.net
http://www.martinreid.com or http://www.cyberramp.net/~upupa
|
|
|
|
BIRDxxxx
BIRDCHAT
ID-FRONTIERS
US:NewEngland
