How to tell the sex of bluebird nestlings
Date: Sat, 22 Apr 2000 09:03:11 -0700
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.
From: Rogerjette"at"aol.com [mailto:Rogerjette"at"aol.com]
Date: Thu, 12 Apr 2001 12:15:34 -0500
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
Bruce Burdett, NH Bluebird Conspiracy,
Date: Thu, 12 Apr 2001 18:13:20 -0400
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.
Date: Fri, 20 Jul 2001 14:33:22 -0400
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....
Date: Fri, 20 Jul 2001 19:43:58 -0700 (PDT)
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
Does a white eye ring indicate the age of a female WEBL??
From: "laura" obi424"at"earthlink.net
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]
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]
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]
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.
From: Torrey [mailto:torrey_canyon"at"yahoo.com]
Sent: Thursday, May 26, 2005 4:23 PM
Subject: Re: Is there any way to tell
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.
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.
HOME - ASO
BEST OF BLUEBIRD_L CLASSIFIEDS HOME | Audubon Society of Omaha | The Bluebird Box | Bluebird FAQs | Search | Contact me
All material was originally posted on the Bluebird_L or Bluebird mailing list, and has been reposted here with slight modifications to make the posts more readable in an HTML format. In cases in which quoted material has been deleted to save space, this is indicated by an ellipsis (...)
For more information about Bluebird_L, check out http://www.cit.corn.edu/cit-pubs/email/using-lists/index.htm. If you wish to contact the author of a post, you will need to edit the e-mail address, replacing "at" with the "at" symbol (above the number 2 on your keyboard). (This change was made to discourage spammers.)
If you are the author of a posting and would like to see a particular post (or posts) removed from these web pages, please contact me with the web page address, title of post, and date and time of the post(s), and I will remove whatever material you like. If you have a different opinion from one posted here, you need not contact me, as often I will have a different opinion too. The intent is to try and provide both sides to the issues facing bluebirders, and to do so in an impartial and objective manner.
If you have problems, encounter broken links (unless they are within an e-mail thread, as I do not maintain those links), or have suggestions on how the site can be improved to make it more useful, please contact the Best of Bluebird-L Classifieds webmaster.
Website design by