How to tell the sex of bluebird nestlings
Date: Sat, 22 Apr 2000 09:03:11 -0700
From: "W.Guglieri" wendyg"at"jps.net
Subject: Re: chick rescue: all done
Pattie:
How do you tell the sex of such little creatures? By day 12,
the primary feathers begin to unsheath, and you can see the
bright blue to the males. It's unlikely that you'd have all
of one sex, so seeing the difference in the the two sexes (femalesare
a duller blue) makes it quite apparent. Of course, I'm speaking
of Western Bluebirds, but I would imagine that the Easterns
are pretty much the same.
Wendy Guglieri
Rescue, California-in the Sierra Nevada foothills 40 mi. east
of Sacramento-wendyg"at"jps.net
From: Rogerjette"at"aol.com [mailto:Rogerjette"at"aol.com]
Sent: Thursday, April 12, 2001 11:51 AM
Subject: bluebirds eyes
Jim,
enjoyed you excellent site. I hope you can answer my question.
I have noticed that some bb's have a more pronounced rings around
their eyes than others. do you know why this is? thanks for
any help you may have.
Roger
rogerjette"at"aol.com
Date: Thu, 12 Apr 2001 12:15:34 -0500
From: "Jim McLochlin" bluebirdbox"at"cox.net
Subject: RE: bluebirds eyes
Roger,
Not sure on this one so I am including the mailing list (Bluebird-L)
in my response to you. The eye rings seem more pronounced to
me in female, young, and some first year birds.
Date: Thu, 12 Apr 2001 15:46:43 -0400
From: "Bruce Burdett" blueburd"at"srnet.com
Subject: Re: bluebirds eyes
In the Eastern Bluebirds that I see here in NH, the adult male
has no visible eye ring, the adult female has a very pronounced
eye ring, and the young of both sexes all have eye rings. The
eye rings of the young males gradually disappear as they grow
older, but they persist, more or less, throughout their first
summer. By the following spring, all the males' eye rings have
vanished.
Bruce Burdett, NH Bluebird Conspiracy,
blueburd"at"srnet.com
Date: Thu, 12 Apr 2001 18:13:20 -0400
From: DottyRogers"at"netscape.net
To: bluebird-l"at"cornell.edu
Cc: Rogerjette"at"aol.com
Subject: Re: bluebird eyes
Roger:
If you pull up www.naturephotosonline.com, click on "Photographers"
then click on "Skip Moody", you'll have 3 pages of
crisp, available-light close-ups of eastern bluebirds; males,
females and young. Nope -- I'm not connected to the site in
any way; just like the photos.
Hope this helps.
Dot
Date: Fri, 20 Jul 2001 14:33:22 -0400
From: "Pamela Ford" jpford"at"home.com
To: bluebird-l"at"cornell.edu
Subject: How to tell sex of fledglings
Hi all,
I'm having a great bluebird season. The female is incubating
her third clutch of 4 eggs. The male is bringing the four fledglings
from the second nesting closer and closer to the house as they
use the mealworm feeder. As I've been watching the fledglings
learn to forage for their own insects I've been trying to tell
their sex. I'm having trouble doing this based upon the overall
amount of blue in their feathers. Are there any other things
to look for?
Also, all three of the clutches this year had exactly four
eggs. Is this a distinctive of the female's age, condition,
health? Everything I read indicates 5-6 eggs are "normal"...
but we know that normal is not easily defined....
Pam Ford
Abingdon, Harford County, Maryland
Date: Fri, 20 Jul 2001 19:43:58 -0700 (PDT)
From: Horace Sher hjsher1"at"yahoo.com
Subject: Re: How to tell sex of EABL fledglings/nestlings
Hi Pam...The way I tell the sex is to look at the tail feathers
only. If you see blue there, it's a male. If you don't see blue,
but sort of grayish dull or dirty blue, then it's a female.
You can really see this difference when you monitor & check
the nestlings when they are at least 9 or 10 days old in the
box.....Horace in NC.
Date: Sun, 16 Mar 2003 16:57:54 -0800
From: Ann&Tom Long longann"at"pacinfo.com
Subject: Eye ring
Does a white eye ring indicate the age of a female WEBL??
Tom Long
Western Oregon
From: "laura" obi424"at"earthlink.net
Subject: Re: Eye ring
Date: Thu, 20 Mar 2003 18:24:54 -0500
According to the information in Pyle's Identification Guide
to North American birds used by bird banders - no. Age/sex is
determined by details of molt and plumage, breeding status and
wing measurements. There is no mention of eye ring information.
Hope this helps..
From: Burnham, Barbara [mailto:Barbara.Burnham"at"zzz.zzz]
Sent: Thursday, June 24, 2004 9:30 AM
RE: Day 7 pics and question! ...
On day 13 I always stop monitoring. By that time, the nestlings' feathers are showing color, and you can see that the wing feathers of males have lots more blue than the females. On both males and females, their tail feathers are very blue. I always look forward to counting the boys and girls at the last nest check, and wishing them luck in life! ....
From: Evelyn Cooper [mailto:emcooper"at"bayou.com]
Sent: Thursday, June 24, 2004 9:42 AM
RE: Day 7 pics and question!
If you notice, some of the nestlings have a white ring around their eyes and some don't. I have been trying to find the information about it, but seems like I remember the female has the white ring. I could have it wrong. Does anyone have this information handy? Evelyn Cooper Delhi, LA
From: Evelyn Cooper [mailto:emcooper"at"bayou.com]
Sent: Thursday, June 24, 2004 10:24 AM
RE: Day 7 pics and question!
The only thing I have found so far about white rings around the eyes is in "Bluebirds Forever" by Connie Toops and it says: "Youngsters develop white eye rings". It did not say it had anything to do with identity whether male or female. I have noticed that some have them and some don't and maybe some are slower about developing them. Evelyn Cooper Delhi, LA
From: Tina Wertz [mailto:tinawertz"at"bellsouth.net]
Sent: Thursday, May 26, 2005 3:08 PM
Subject: Is there any way to tell
Is there any way to tell whether a fledgling with be an adult male or female? Just curious.
Tina Wertz
Woodstock, Ga.
From: Torrey [mailto:torrey_canyon"at"yahoo.com]
Sent: Thursday, May 26, 2005 4:23 PM
Subject: Re: Is there any way to tell
Hi Tina,
You can sex Eastern Bluebirds at 10 days old. I don't know about the other species of bluebird.
At 10 days, about 1/4" of wing feather is exposed.
(The feathers start to break out of the sheathes at Day 7.) The tips are a brownish-black, but there will be a color difference above that. The young male will be a noticeably brighter blue, especially in the coverts (the feathers right above the long flight feathers). The young female will be brownish-blue or even just brown.
It takes a bit of practice, looking at different nests of young. (I'm always iffy about the first couple nests that i band.) Sometimes all the babies in one nest are the same sex, which is also confusing because then there's no contrast. Once the young are older & their feathers get longer, it's easier to tell. If the parents bring the kids around to your feeder or birdbath, you should be able to see the difference pretty easily.
All of my other birds have identical plumage as adults, so there's no way to sex them as nestlings.
(OK, House Sparrows you could probably do, but i've certainly never let a HOSP nest get that far.)
yours, Torrey
Torrey Moss
Kalamazoo Nature Center
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