Another Harlan's x Rough-legged Hawk Hybrid?

posted by Jerry Liguori at
on Friday, February 7, 2014 

I love when people share photos with me because there is so much to see out there; the plumage variation is endless for some species. I also get excited when I see birds like the one below in my inbox! My first thought as I saw this image ('click' to enlarge) was "could this be another hybrid buteo?" So I opened the image to full size for a closer look. This bird was photographed by Jill Smith in Prowers County, CO and she was happily willing to let me post it on the blog (thanks Jill). She had sent the photos to Christian Nunes originally, who thought I'd like to see them (thanks Christian).

So is this bird a hybrid? Well, I don't pull the hybrid card quickly, I like to rule out any odd variation of one species first. But, if a bird clearly shows traits of two species and is beyond the plumage of a single species, I feel safer call that bird a hybrid. And confirmed mixed pairs and hybrids are being found in greater numbers than ever now with the amount of photographers out there these days!

Let me hear your thoughts on this bird...

Blogger Holly Thomas said...

Hi Jerry,
I don't have that much field experience with Harlan's or Rough-legged hawks, but I'll put in my two cents anyway. I think it's a Harlan's. Its shape looks red-tail to me. Most of the plumage traits are consistent with my understanding of adult Harlan's. What most suggests Rough-legged are the apparent carpal patches, but I'm not sure I'd be willing to say hybrid on just that. I'll be curious to read what others see on this bird.
BTW it's a gorgeous bird and I'd be happy to see something like this any time.

February 8, 2014 at 8:01 AM  
Blogger Jerry Liguori said...

Thanks Holly, thanks for your evaluation! I'd love to see the topside of the bird, maybe it will get tracked down again for more photos.

February 8, 2014 at 8:15 AM  
Anonymous Derek Lyon said...

Traits that I would class as Harlan's: overall shape, wing shape, underwing barring, but is missing patagium. Traits that I would class as Rough-leg are: carpal marks and necklace band of white above bellyband. I'm an eastern hawkwatcher and only know Harlan's from photos, but I've not come across a Harlan's without a patagium, having carpals or a necklace like this. A view from the topside could help decide, but for now I'd go with a Hybrid of the two for now.

February 8, 2014 at 10:42 AM  
Anonymous Anonymous said...

I'm thinking hybrid for the simple reason that it just doesn't look right to my eye for a Harlan's or a Rough-legged and looks like it could be a mix of the two.

February 9, 2014 at 7:16 AM  
Anonymous Hatem Gomaa said...

I personally think it's a Harlan's red tail. The head is completely RT, especially the side view of the 2nd and 3rd photo. The first photo (on the left) is also completely RT with that dark head and that white that surrounds the bill and cere and the the throat patch - take a look at this photo of a Harlans face it's exactly what you see here -

And as far as the patagium and the distinct carpal patches of rough legs, I don't think that's a definitive way of looking at it because IIRC, there are some dark Harlan's that don't have dark patigial markings - exhibit A -

That's about as Harlani as it gets without any dark patagial marks and it's just the same dark color of the wing chord.

As far as the carpal patches that is such an identifying mark for rough legs, well, guess what? Yep, good ol' Harlani also sometimes develops that dark carpal patch Exibit B -

The huge, dark belly band that's also synonymous with rough legs is also something you see occasionally on Harlan's - Exhibit C -

The wing length is a little tricky but it doesn't seem like it's as long as the RL and the tail is pretty long like RL but still, some RT's are known to have long tails as well.

If we could see the legs......and they were rough with little feathers and booted like the RL, then I would be sold. But can't see those.

So the plumages don't confirm it for me and neither do the physical characteristic and without seeing the feathered legs, I'll go with just "unique" Harlan's RT.

Jerry and any one else is more than welcome to correct me if I'm wrong with any of the examples and things I've stated. :)

February 9, 2014 at 9:18 AM  
Blogger Jerry Liguori said...

There's no right or wron here, I'm just looking for opinions. The only comment is that the juvenile bird in one of those links looks shadowed at the carpals and may be what is contributing to the dark carpal look. And when even western RT's can show solid underwings coverts that mask the patagials, but when they are barred on the underwing coverts, the patagials are typically solid and darker.

Otherwise, I appreciate the comments as always!

February 10, 2014 at 4:30 PM  
Blogger T MF said...

Hi Jerry,
I've been following your blog for a while now and have read your ABA journals pertaining to Red-tailed Hawks. Most of what I have learned about Red-taileds I can attribute to your published research. I have not posted here before but I am familiar with these photos so I thought I'd chime in.

I must say, when the photos of this bird were originally posted on a Colorado birding group page I was one of the first respondents to practically shout "Harlan's Hawk!" I gave all my reasoning (black/white plumage, white chest, white tail with diffuse dark subterminal band, banded primaries...). I ruled out Roughie right away because I didn't see enough darkening in of the carpal area and I felt the primaries were too banded. I was stunned to have a fellow birder jump on and correct me by saying "Dark-morph Rough-legged". Clearly this was a Harlan's! However, I have since been forwarded images of this bird and I am looking at them in full screen as I type this. I have looked very closely. I could make a case that this bird is a tad long-winged and long-tailed for a Red-tailed, but that is a tough call with every photo being at an angle. There may be a ghost of a carpal patch under those wings and perhaps the patagials are rather weak/nonexistent (and I'd expect them to show stronger with that amount of underwing mottling). A case could be made for those multiple black tail bands leaning toward male adult Roughie. In the profile shots, the bill does seem rather petite. My verdict? Dunno. It's definitely at last half Harlan's; that much is certain! We are all hoping the bird is refound. Then maybe we can take a good look at those tarsi!

I'm not putting anything past Buteos as far as hybrids go; someone on a raptor count in PA just last week witnessed a RTHA and RSHA copulating and posted some photos. I know that's not a first, but still rather rare as I understand it.

Thanks for discussing this bird! All the best.

Tami M

February 11, 2014 at 4:57 PM  
Blogger Jerry Liguori said...

Hi Tami:

Great to see you on the blog, hope you comment more often. Please, if you do get to see more photos, I'd love to see them too.

February 11, 2014 at 6:12 PM  
Anonymous Ron Dudley said...

Fascinating, both bird and comments.

February 12, 2014 at 6:14 PM  
Anonymous Hatem Gomaa said...

I guess there are some critical questions to ask about hybridization in raptors (or even just buteos in this case) so one can know what to look for when confronted with a unique bird such as this one. One question would be if there are any previous examples or specimens that have been studied and then information published as to the dominant traits from each species that would more likely show up in a hybrid bird. I'm guessing there isn't much information, if any, since it's kinda rare and it's only been recently that we're seeing more of these occurrences because of people getting out there with cameras and the Internet etc. But I do recall coming across a site where some study skins of hybrid buteos were studied and discussed but there wasn't much detail beyond the things mentioned in many of the comments here. If we could better understand the dominant traits of each species that are more likely to show up in the offspring, then it would be easier and more accurate to gage and to know exactly what to look for. What are the greater probabilities of the famale's traits showing up. What about the male's? Is there a pattern or does it vary from individual to the other? If the male is a rough leg and the female is a red-tail, will the male's plumage and physical traits show up more or the other way around? What about the DNA of hybrids? If you took the DNA of two separate hybrids (both RL x RT) would that DNA be identical for both specimens? For hybrids all across? Then there's also the possibility of the single species itself being an oddity or a unique bird. It could possess some "likeness" to both species but in reality is one or the other because they already share so much in common in the first place. So many things to ponder....such little time.

February 13, 2014 at 7:59 AM  
Blogger Jerry Liguori said...

Hatem - I have to catch my breath after reading all that, hee hee

February 13, 2014 at 8:40 AM  
Anonymous Hatem Gomaa said...

Bring it, Jerry! :)
We still haven't heard your opinion BTW.

February 13, 2014 at 9:25 AM  
Blogger Jerry Liguori said...

I guess the true purpose of this post is to hear others, it is a good thing for me to stay out of it on purpose and just listen. I don't have some kind of final say of course and posted it because I want to hear unbaised opinions. Like I said, there is no wrong or right in the end...

February 13, 2014 at 9:40 AM  

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