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Raptors Breeding in Juvenile Plumage?

posted by Jerry Liguori at
on Friday, June 7, 2013 

My friend Shyloh sent me a photo today that reminded me of a post I was meaning to get to (too many to get to and not enough time). Check out the Cooper's Hawk sitting on its nest…it is in juvenile plumage, which means it was born last year. Many (but not all) raptors are sexually mature at this age and breed successfully. The first time I noticed something like this was about 22 years ago when surveying Bald Eagle pairs on the East Coast…although, I'm sure it had been documented before that. I witnessed a few eagle pairs where one of the pair was not quite in full adult plumage, having a dark tail tip and some dark on the head. Each time this occurred, it was the female that was the "non-adult." And this makes perfect sense since it is the female that chooses the mate. And would a female choose a young male or an adult male? It's a no-brainer, an adult is going to be chosen every time. In fact, I haven't seen a breeding pair of raptors where the male was in juvenile plumage, but if anyone knows of this occurring, let me know, because its bound to happen. It has been reported that immature male Harriers have helped adult males tend to a female with nestlings, but I can't verify that at the moment (not sure where it was cited).
Anyway, check out the male in the second photo, he's in adult plumage, but still has a pale eye, which indicates that he likely acquired his adult plumage last year. Eye color is not always accurate to tell specific ages, however, males change eye color quickly, and a pale-eyed adult male is almost always one in its first adult plumage. This is definitely not the case with females though who can take years and years to get a red eye (and sometimes never do). Also note the gray cheek of the male, females can have grayish cheeks but it takes them several to many years to show that. So, this is an interesting pair;.a female in juvenile plumage and a male who isn't much older (most breeding males have dark red eyes). By the way, some of this pertains to my next post….

13 Comments:
Blogger Dick Ashford said...

Hi Jerry, An immature-plumaged female Red-shouldered Hawk successfully bred with an adult male in a tree behind my house (Ashland, Oregon) in Spring 2007. It was the first I had ever heard of immature - plumaged birds reproducing. Thanks for the blog! Great stuff!

June 7, 2013 at 11:10 PM  
Anonymous Jerry Liguori said...

Hi Dick:

Thanks for the info, and I'm glad you enjoy the site!

June 8, 2013 at 7:25 AM  
Blogger shyloh monster said...

Thanks for this post Jerry. I'm fascinated with the pair and enjoy checking in on these two birds. Much of the time I'm observing behaviors and soaking in all I can. I never considered age factors with the pair and appreciate your insights. Enriching stuff!

June 8, 2013 at 3:52 PM  
Anonymous Jerry Liguori said...

Shyloh:

Thanks for sharing the photos, I'm glad you and others find the blog helpful. I love that you study bird behavior!

I plan to blog quite a bit and want to share stuff not quite worthy of full articles but stuff I find interesting...

June 8, 2013 at 5:48 PM  
Anonymous Mia McPherson said...

Great info Jerry! I seem to recall a pair of Bald Eagles in Florida where the male wasn't as old as the female and still showed some black on the tail and the face, I will contact a friend who took images of that pair just to be sure and will let you know.

June 9, 2013 at 5:22 AM  
Anonymous Jerry Liguori said...

Hi Mia:

Thanks for all your recent comments and help!

June 9, 2013 at 8:06 AM  
Anonymous Jerry Liguori said...

Just for info update matters...a few people have e-mailed me to let me know they have seen or heard of male raptors breeding in juvenile plumage

June 9, 2013 at 10:53 AM  
Blogger Vic Berardi said...

Excellent post Jerry, really enjoyed this one!

It is informative and enlightening, thank you for sharing your knowledge and experience on things like this. There's so much to learn and that's what makes it so much fun. And thanks to Shyloh for this unique documentation!

Love this blog and keep these posts coming!!!

June 9, 2013 at 5:17 PM  
Blogger Jerry Liguori said...

Vic:

Thanks for the kind words...so glad you like the blog. More to come and more tidbits on Red-tails soon since I know you like them!

June 9, 2013 at 7:03 PM  
Anonymous Ron Dudley said...

Fascinating stuff, Jerry (and Shyloh). I can tell I'm going to learn a lot here. I pulled your book (Hawks From Every Angle) out of my shelf just yesterday to check something on a recent Swainson's Hawk post and now I have yet another resource from you. Couldn't be happier about that.

June 11, 2013 at 6:16 PM  
Blogger Jerry Liguori said...

Wow Ron....glad you like the blog. I hope to blog often and hope to have tidbits to share.

June 11, 2013 at 7:40 PM  
Anonymous Anonymous said...

I was very glad to read this post. I have been watching two Cooper's hawk nests for a volunteer program in the Cleveland Metroparks this season. These two particular nests had hawks that appeared to be in juvenile plumage.

The nest in the first photo didn't get to incubation. The nest in the second image recently produced four fledglings.

http://www.flickr.com/photos/ken-a/8858231026/in/photostream/
http://www.flickr.com/photos/ken-a/8892741011/

Ken Andrews
Maple Heights, Ohio

July 8, 2013 at 12:54 PM  
Blogger Jerry Liguori said...

Ken:

Thanks for the links, and you are correct of course (definitely juvenile plumage). I love seeing this kind of stuff!

July 8, 2013 at 1:02 PM  

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