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Another Harlan's vs. Krider's

posted by Jerry Liguori at
on Saturday, November 16, 2013 

Daryll Myhr shared these adult Red-tailed Hawk photos with me from British Columbia (thank you Daryll). He has shared lots of photos with me over the past few years, and it is always great to see what he has for me in my inbox. This is one of those birds that gets people wondering if it is a Krider's or Harlan's, and for good reason. Some light-morph Harlan's look similar to Krider's and some of the plumage traits overlap at times…and hey, they should, they are both Red-tailed Hawks. However, there are definite ways to distinguish faintly marked, pale-headed Harlan's from Krider's. We summarize this pretty well in 2 articles in a 2009 issue of Birding magazine if anyone wants to download it here:

www.aba.org/birding/v42n2p38.pdf‎
www.aba.org/birding/v42n2p30.pdf‎

Anyway, check out the dark, cold brown upperside and head, white streaks on head and over the eye, pale mottling limited to the scapulars, brownish mottling on the tail, distinct / blobby belly streaks, and snow-white body plumage. These are all Harlan's traits. This just happens to be a Harlan's with a white-based tail ( a common tail type on light adults), which is what causes most of the confusion. Although it's fairly out of range for Krider's, I don't ID birds based on range or probability, just on sound ID criteria such as plumage and structure. To clarify -- adult Krider's have buffy underbodies, thin belly streaks, warm brown uppersides, (often) extensive, pale mottling on the upperwing coverts, and uniform whitish heads (often lack white streaking), or golden brown heads (not dark, "cold" brown. The tail of adult Krider's is often whitish with a pinkish tip, but not mottled with gray or brown like this bird. There are other differences as well, but the birds wings are not spread in these photos, so I won't mention them…they are mentioned in the articles though.

I hope this helps people separate these two similar subspecies, and feel free to comment or ask questions, hopefully I can answer them.


Happy Hawkwatching!

27 Comments:
Blogger D Myhr said...

What I didn't feel confident in was the color should have been more blackish- dusky black and the tail length seemed short. Anyway, RT's are tricky at times to "put in a box".
Daryll

November 16, 2013 at 10:56 AM  
Blogger Jerry Liguori said...

Your too humble, you nailed it as Harlan's Daryll, good call. I agree though, they are tricky, I have a folder of RT's labeled "unknown", they are weird ones....dark and light. I have my suspicions and could be correct, but they are unknown in my files, so that says enough for me. I always know when to be cautious on these things. Besides, it would be impossible to know if I were right or wrong on some of them.

I'll post a few "unknown" RT's on the blog, it will be fun...

November 16, 2013 at 11:03 AM  
Anonymous M. Bernardo said...

Excellent tutorial Jerry!

Your expertise and willingness to share it are much admired. Thank you for this blog, I check it daily and am excited to see when a new post comes up, many tid-bits of neat information on your site.

November 16, 2013 at 3:45 PM  
Blogger Jerry Liguori said...

Thank you M. B. That is very nice to hear, and one of the reasons I have a site...so people like you might enjoy it. I love raptors and writing about them!!!!!!!

November 16, 2013 at 3:49 PM  
Anonymous Anonymous said...

Ditto to what M. Bernardo said. Thanks for the tips Jerry.

November 17, 2013 at 4:25 PM  
Blogger D Myhr said...

Re RT subpecies list: one report listed 14 subspecies another 15 belonging to Buteo jamaicensis: the odd-ball was Buteo jamaicensis suttoni. I was wondering is there a "type" photo and description of each Subspecies listed and identified as the "standard" which one can go to for a "first-look". In reading birding books, I get a range of subspecies and their related morphs that can be confusing at times. There must be a document that fingers the "model bird" for each subspecies, do you know of such?

November 25, 2013 at 8:23 AM  
Blogger Jerry Liguori said...

Hi Daryll

There is supposed to be a "type specimen" for all species and race of birds. However, it can be misleading to look at a single example and base all other Id's on that example. AND, type specimens are sometimes misidentified, either adult or juvenile, or even a painting in one instance i can remember. So, it is mch better to do a google image search in reality (but many pis on google are incorrect). So, I wish I could help more, but that is the reality of it.

There is not one place to see the type specimen photos, the specimens are various collections around the country/world, and even those are tough to use since they are birds with their wings and tail folded in.

November 25, 2013 at 12:30 PM  
Anonymous Hatem Gomaa said...

I think the lack of an officially recognized publication or document showing the 14 subspecies of red tails with several photos of each that would depict the typical and the ends of spectrum variation of plumages is most likely because people are still debating about a 1 or 2 of them and their designation, and arguing their characteristics until this day, is my guess. Heck, is the debate as to whether the Harlan's is a red tail or a separate species, settled yet?! Even if the debate miraculously reaches an overall agreeable conclusion based on solid DNA testing and as many other convincing proofs as possible, there will be some sighting and some photograph of......get this.....a "red tail"....that will most likely pop the debate can open again.

Perhaps a book that shows the North American subspecies only, and not necessarily the Mexican and Cuban and Panamanian or West Indies variants would suffice (for now). So it could clearly depict the Borealis, Calurus, Krideri, Fuertesi, Umbrinus and then list the Harlani as the trouble maker! It still wouldn't be too difficult to describe the Harlan's, either, as part of the Buteo Jamecencis. And Jamecencis itself confuses things since the Bahamanian/Cuban subspecies is referred to as Jamecensic. I think now we know why there's no definitive literature!

In some ways, thank God, that here in the north east when we see red tails, it's settled immediately! But then again, we (certainly I) are envious of the magnificent variety of plumages found in the west.

November 28, 2013 at 8:27 PM  
Anonymous Hatem Gomaa said...

Is it possible that this particular bird in the above photos (and BTW she is absolutely stunning!) has partial albinism, or some form of leucism or melanism? I ask because of a few, particular feathers on the back. You can see some of those scapulars that have the distinct white halves, but then there's that one tertial feather that is completely white (a common leucistic and albinistic trait) as well as the 5th primary has the white tip and seems to be the only primary out of the batch that is exposed showing a white tip. What made me think of that is I had seen, many years ago, a photo of a Borealis that was completely normal colored with the exception of 1 single tertial feather that was fully white. It was in Wild Bird magazine. What do you think, Jerry?

November 28, 2013 at 8:37 PM  
Blogger Jerry Liguori said...

Yes, but I didn't mention it because the white streaking on the head and white based tail are not from leucism and didn't want to confuse people or distract them from the purpose of the post

November 28, 2013 at 9:33 PM  
Blogger Jerry Liguori said...

Hatem -- your comment about showing all the subspecies variation deserves its own book!!!! And even that would likely be confusing and full of subjective ID's. Also, some races themselves are debateable as to whether they are justified, but I won't talk about that on a simple blog.

I haven't heard of any debate on whether Harlan's is a species? As far as I know, it is an accepted subspecies of the Red-tailed Hawk. The DNA does show it is a Red-tailed Hawk, is there debate over the study? I don't think any taxonomists are debating this....that's for them to blog about. Or maybe I will blog about what I am privy to up until now.

November 29, 2013 at 7:19 AM  
Blogger D Myhr said...

Hatem's comments and yours of Nov.25-28 have merit and as a novice birder and 'hawker" I like the idea of a "type" specimen(s) and then some details for the range( of morphs) that they may exhibit. For example- William S.Clark's article in Birding (vol 41,No 1,Jan. 2009) begins with the Type specimen for a Harlan's in his report Extreme Variation In The Tails....differs from Red-tailed Hawks. In geology, type-sections describe and document a formation. Variation(s) from this are either, facies equivalents or warrant a new name( and type-section). Yes, a retired geologist I am and so I could see that the Rt's and their subspecies would have to have a type-specimen and after that the blogs and reports and books would and have evolved. Jerry,"subjective ID"S", well not if a few of you experts got together and nailed down the type-specimen from each region and its Type-morph . After that we with less experience can argue the merits of an ID.

November 29, 2013 at 5:26 PM  
Blogger Jerry Liguori said...

Working on it Daryll...please keep commenting!

November 30, 2013 at 5:57 AM  
Anonymous Hatem Gomaa said...

Jerry, how rare is this particular bird, as far as light colored Harlan's with so much white and even some luecism (if you agree that it does have some of that)? Is this someone rare to see this color variation or is it more common than one would think?

Daryll, how often have you seen this bird? Do you have any other shots of the face? That color variation and dark eyes is just spectacular! Also, what approximate distance were you from the bird while taking these photos?

December 3, 2013 at 3:45 PM  
Blogger Jerry Liguori said...

Hi Hatem

Considering all the variation, this bird is pretty typical of a light adult. The few white feathers is as common or more on Harlan's than on other races. But that is speaking from field observations and mental notes, not actual comparison data.

December 3, 2013 at 3:54 PM  
Blogger D Myhr said...

Guys: seen only once. First rear shots close ,say 100m away ,frontal shot 200-300m away.I will forward all my shots to Jerry and he can forward to you as I have his email address, not yours. I was shocked by the brilliant white the bird displayed and the Harlan-like tail color.

December 3, 2013 at 5:15 PM  
Anonymous Hatem Gomaa said...

Well, you got some pretty good shots of a real beauty. And thanks for sending that other photo. This bird has those really dark, adult eyes you see every once in a while and it seems to go well with the rest of the colors. Great!

December 5, 2013 at 5:29 PM  
Anonymous Hatem Gomaa said...

Thanks for the answer on the rarity question, Jerry.
BTW, if anything like this ever showed up in this neck of the woods, there would be panic and pandemonium and all kinds of calamities with people loosing their minds out of excitement! There has been, though, several documented cases of leucistic eastern red tails in New England, but they are far and few between. Waiting for the day to be able to photograph one with good, sharp clarity. Last time we had a grey phase gyrfalcon in Boston, people were coming from Japan just to see it!

There was also, probably what many would describe as one of the most unusual and rare sightings for raptors that occurred about 9+/- years ago and that was a red footed falcon found hanging around on Martha's Vineyard. That was pretty crazy considering it's an eastern European raptor that migrates to Africa and back. Do you recall this at all, Jerry?

http://virtualbirder.com/vbirder/rba/rffa/

December 6, 2013 at 6:56 AM  
Blogger Jerry Liguori said...

I do recall it, crazy when birds show up here that are from far away!

December 6, 2013 at 7:43 AM  
Anonymous Hatem Gomaa said...

There was a HUGE debate as to whether it was truly a vagrant or someone's bird that got away. I tend to believe the latter. The distance in this case is just too much for a bird of that size to pull off and the terrain makes it even less likely. We're talking about crossing the Atlantic Ocean! Its natural migration has mostly land so easy call on that one, for me at least.

Jerry, someday if you feel up to it, it would be great to see some of those "unknown" red-tail pics you talked about above. If there are RT's that stump even the Jerry Liguoris of the world, heck, these things must be crazy odd and a lot of fun to take a stab at! :)

December 7, 2013 at 7:29 AM  
Blogger Jerry Liguori said...

I think I will show some, but I'm working on an article, so it will have to be after that....

I can surmise what I think they are, but it is truly impossible to know for sure o n some birds and that's the nature of birds!

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

Indeed, and the overlapping of the red tail's range with so many variants to begin with compounds things exponentially. Hopefully it doesn't reach a point where they're so mixed that there are more birds that are intergrades than there are pure subspecies. It certainly seems to be heading in that direction! Or perhaps there is just much more awareness these days and we're only discovering what's actually been out there for a long time out of raised interest and the growing availability of photos and of course, the wonderful internet. Hard to asses.

December 7, 2013 at 9:22 AM  
Blogger Jerry Liguori said...

Much more awareness and sharing of photos!!!

December 7, 2013 at 9:27 AM  
Anonymous Hatem Gomaa said...

Jerry, what's your feeling with regards to the possibility of the species moving towards a very large population of intergrades more than pure sub-species? Do you find that trend increasing through the many years that you've been observing these birds?

December 12, 2013 at 4:06 AM  
Blogger Jerry Liguori said...

I do find it happening with Red-tails, but that is just a perception based on what we know now compared to what we knew way back when. It could be that we are just catching up on our learning, some of the old literature says this too. So, maybe it has always been and we are just more aware of overlap and intergrading because more areas are accessible and there are more eyes looking.

Habitat is changing too, and that is a factor

December 12, 2013 at 6:58 AM  
Blogger D Myhr said...

A site I use to compare BC Hawks wih our more northern neighbours is Yukon Red-Tailed Hawks found on the Flicker.com web site. Very good pics and ID's I feel.

December 12, 2013 at 7:30 AM  
Blogger Jerry Liguori said...

Thanks Daryll...I'll check it out!

December 12, 2013 at 9:35 AM  

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