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Aberrant Plumaged Raptors

posted by Jerry Liguori at
on Sunday, May 19, 2013 

There are lots of examples of birds that vary from the "norm", so I thought I would show a few raptors I have encountered with unusual plumages.....I have too many to show here and now so sorry, but hope this is interesting ("click" on images to enlarge).
An adult Red-tailed Hawk that nests in Utah with Harlan's-like whitsh mottling on the chest. I have seen several examples of Western Red-taileds with this trait.
Dilute plumaged juvenile Red-tailed Hawk from 1999 at the Goshute Mts., Nevada. Cream-colored birds such as this are better described as "dilute" than leucistic (which means white).
Adult borealis Red-tailed Hawk at Gunsight Mt., Alaska from April, 2009. Not an odd plumage, but significant to note that a fair number of borealis and calurus occur in Alaska.
Leucistic adult Harlan's Red-tail from Idaho (2004, left) and a recent photo of a bird that is possibly the same bird from Oklahoma (?).
Juvenile Merlin that lacks multiple tail bands, this occurs from time to time. Photo taken many years ago at Cape May Point, NJ.
Adult Rough-legged Hawk that could be considered an "intermediate" morph, photographed a few years ago in Utah in winter.
Juvenile Rough-legged Hawk that could be considered an "intermediate" morph, photographed a few years ago in Utah in winter.
Check out this juvenile dark-morph Swainson's Hawk with a white-based, dark-tipped tail? Photographed along the Wasatch Mts, in Utah one September day a ways back. Most likely an aberrant tail and not a hybrid. I have seen a few examples of this....
Note the dark chest on this juvenile Ferruginous Hawk...how do we explain this? A fairly dark head (and eye) for a juvenile as well. Is this an intermediate-morph, who knows?
An unusually heavily marked juvenile Broad-winged Hawk from the Keweenaw Peninsula, MI. These markings are purely juvenile, not adult markings due to molt, however, the primaries with dark tips on the right wing are new adult feathers.
  
Adult Broad-winged Hawk taken last week at the Keweenaw Peninsula, MI  with a white belly. This makes for a beautiful bird!
 
Juvenile Broad-winged Hawk from the Wasatch Mts., Utah with an adult-like tail. I have seen several examples of this and several juveniles with a dark trailing edge to the wings (similar to adults) but with juvenile body plumage. Why? I have no idea, just chalk it up to variation.
Juvenile Northern Goshawk from spring 1994 at Braddock Bay, NY. Why does it have a brown eye when it is supposed to have a pale yellowish eye?
Nearly completely dark Northern Harrier photographed in February 2008 at Farmington Bay, Utah. Of course I wish it were closer, but them's the breaks. Only 4 or 5 "dark" Harriers have been seen in North America.
Adult male Northern Harrier (Farmington Bay, winter 2004) with rufous highlights in the tail and upperwings coverts. Just an odd variant.
Juvenile Cooper's Hawk with dark streaks on the undertail coverts similar to Goshawks....it happens. Photographed in October 2007 along the Wasatch Mts., Utah.
Adult Cooper's Hawk with white eye? Photographed at the Goshute Mts., Nevada several years ago.
Adult Cooper's Hawk (second-year) with unusual, widely-spaced barring on the underside from the Goshute Mts., Nevada September, 1998.
14 Comments:
Blogger Mia McPherson said...

Interesting variations of plumages here Jerry!

May 20, 2013 at 7:41 AM  
Anonymous Jerry Liguori said...

Thanks mia...maybe I'll post others. I'm enjoying the blog and have a lot of posts in mind, hope you enjoy them

Jerry

May 20, 2013 at 9:05 AM  
Blogger Bryce said...

Now this is what I am talking about! You didn't even hold back. I love the dark chested ferrug, and Vic's BWHA, and the leucistic Harlan's. Crazy stuff. Glad to see it!

May 20, 2013 at 11:04 PM  
Anonymous Jerry Liguori said...

Glad you like the birds Bryce....I have lots of other oddballs. Love your blog posts as well.

May 21, 2013 at 7:14 AM  
Blogger Nelson said...

Jerry- You can add 1 to the 5 sightings of Black,black-type Harriers. In Mission Bay, San Diego, in winter 1999-2000, I observed a black-type Harrier in flight. The raptor had a all black dorsal area, as black as a crow, with a white rump patch. The ventral areas were brown-orange,
brown, dark brown, and black.
Also, in Mission Bay. 1 fully mature Cooper's Hawk, female, perched on a wall at close range. This accipiter had an all black head. It was a striking site- the red eye and the black head. The best - Nelson Briefer- Goshawk specialist- Anacortes, WA.

May 28, 2013 at 12:00 PM  
Anonymous Jerry Liguori said...

Thanks for the info Nelson...good to know.

Jerry

May 28, 2013 at 1:09 PM  
Blogger Tim Avery said...

This comment has been removed by a blog administrator.

May 28, 2013 at 7:47 PM  
Blogger Unknown said...

You can also add a dark morph NOHA from Weld County, CO on Aug 26, 2009.

May 31, 2013 at 6:41 PM  
Anonymous Jerry Liguori said...

Oh definitely....that was one of the 4 or 5 I was referring to. A great record and great documentation!Thanks for the note, and the interest in the site and feel free to comment on anything at all.

Jerry

May 31, 2013 at 7:49 PM  
Anonymous Hatem Gomaa said...

Hi Jerry,

great stuff as usual. I have a question regarding the juvy broad-winged hawk with the adult-like tail in the 7th pic up from the bottom - depending on what time of year that bird was photographed, is it possible that it was going through it's molt and that the tail is actually the newly molted adult one? Same thing with possibly they outer primaries? They seem adult-like as well.

I think (correct me if I'm wrong) but there's no set pattern for feathers molting in any specific order in most raptors, but I do think that from juvy to adult, it seems to happen everywhere within the same time frame, more or less, just equally (which BTW is a fascinating subject on its own). In other words, the body, ventral and dorsal could exhibit molted feathers already in new ones scattered about as well as the tail and wings at the same time. I don't think there is an order, for example tail first, then wing, flight feathers, then dorsal feather etc and so is it plausible for it to be the case in that one photo, or not? Of course the time of year will probably the best indicator for that.

December 6, 2013 at 5:43 AM  
Blogger Jerry Liguori said...

Yes, its possible, but the problem is I have seen fresh juvs with tails like this on severl ocassions, especially dark-morphs, so I just wanted to point out that this occurs

There is a set pattern of molt, especially the first molt.

December 6, 2013 at 7:49 AM  
Anonymous Hatem Gomaa said...

Really incredible! How interesting is it that such a feature could easily be overlooked, especially in-field is much harder to pick up. Once you have the photos, it's evident and almost like a door of endless oddities opens up.

When you have some time, could you kindly give us quick run-down on the molt pattern? I'd love to learn about that. I never knew there was one, but noticed that there is balance when the feathers fall out. You almost always see the same primaries on each wing timed together. Same as tail feathers and so on. A neat occurrence and you can easily understand why that would happen.

December 7, 2013 at 8:54 AM  
Anonymous Hatem Gomaa said...

Is it safe to use the dark, center line on the throat to identify juvy broad winged hawks? I think it's the only buteo to have that in it's juvenile state.

December 14, 2013 at 2:29 AM  
Blogger Jerry Liguori said...

Its a fairly good mark, but not totally reliable. A friend just mentions this in an article coming out soon and I made sure to show him photos of Broad-winged and Red-shoulder with identical throat patches. Just like the accipiter throat patch blog post, it is good but not 100%

December 14, 2013 at 6:22 AM  

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