Is this light-colored Red-tailed Hawk a Krider's?

[smittyone@cox.net]

DeSoto NWR near Missouri Valley, IA in August 2015.  Is this light-colored Red-tailed Hawk a Krider's.  Follow-up question.  Since eye color can change slower than plumage changes, in this particular bird would you ignore the yellow eyes and call it an adult, based on its tail feathers?

[Birds are cool]

Looks like a Krider's to me.

[Avery]

1 hour ago, Birds are cool said:

Looks like a Krider's to me.

How are you eliminating pale borealis? That crown is pretty dark. 

[smittyone@cox.net]

I've got a yes and a maybe not.  Anyone else wanna chip in please?  I've got lots more pics, but I think the ones I posted include all the necessary angles.

The age question also remains unanswered

[Birds are cool]

9 minutes ago, smittyone@cox.net said:

I've got a yes and a maybe not.  Anyone else wanna chip in please?  I've got lots more pics, but I think the ones I posted include all the necessary angles.

The age question also remains unanswered

I have no idea about the age.

[Jerry Friedman]

On 3/6/2023 at 4:34 PM, Avery said:

How are you eliminating pale borealis? That crown is pretty dark. 

There's a very fine line between pale borealis and krideri... And that barely existent patagial mark seems to suggest Krider's.  Maybe the good folks on Facebook would be interested in this one.

[Jerry Friedman]

The age of this bird provoked a lot of discussion on Facebook.  Apparently I was wrong to call it an adult.  I'm just going to quote three replies on the subject.

Gail Kozun Bruckner: Your bird is a juvenile, even though the tail is rather red, there is no thicker subterminal band, and we can see it does not have a darker edge to remiges. The belly band is very simple.

Abu Anka: See Wheeler, "Birds of Prey of the West" 2018; "Orange or rufous dorsal tail surface is common on 'Eastern' juveniles and can be nearly as rufous as adults".

Mike Borlé: Jerry Friedman, I think we've finally landed on the fact that this Red-tail is in juvenile plumage. To put it totally to rest, can you ask your friend for a shot showing spread wings? The lack of any molt and lack of a thick, dark trailing edge to the flight feathers will be very apparent.

Part of the problem seems to be that rufous tails among juveniles are less rare in the East than the West, though Wheeler's "common" may be an exaggeration.  So a Westerner though the rufous was a sure sign of adulthood.

This is the only comment on the subspecies:

Mike Borlé: This bird is a pale plains-type eastern juvenile in my opinion. This bird fledged, by all accounts in far south-western Iowa. If memory serves, neither Nebraska or Iowa have any compelling Krider's breeding records. So although there might be a bit of Krider's influence bleeding into surrounding areas, we can't be sure. What there are in these areas, are plenty of pale eastern-types with minimal or absent bellybands and so on. Hope that helps.

Also a poster named Melissa Beyer commented, "Absolutely amazing photo!"

Edited March 9 by Jerry Friedman
missed on

[Clip]

On 3/6/2023 at 4:48 PM, smittyone@cox.net said:

DeSoto NWR near Missouri Valley, IA in August 2015.  Is this light-colored Red-tailed Hawk a Krider's.  Follow-up question.  Since eye color can change slower than plumage changes, in this particular bird would you ignore the yellow eyes and call it an adult, based on its tail feathers?

Beautiful Bird and photos.

[smittyone@cox.net]

These two throwaway pics are the best I have showing spread wings.  I assumed they wanted underside.  Unfortunately, I have no topside wingspread pics.

[smittyone@cox.net]

So we're decided on an immature bird, likely a lighter than normal Eastern borealis. Easterns only come in light morph, right?  And what is a "Plains" eastern??

[Jerry Friedman]

That's a different bird.  The original one has almost no patagial marks and a belly-band of round dark spots, and the one in the new photos has heavy patagial marks and a cross-hatched pale belly-band.

[Jerry Friedman]

3 minutes ago, smittyone@cox.net said:

So we're decided on an immature bird, likely a lighter than normal Eastern borealis. Easterns only come in light morph, right?  And what is a "Plains" eastern??

Yes, a juvenile, and yes, Easterns only come in light morph, though as @chipperatlsaid, that still includes variation.  A "plains-type Eastern" is what Mike describes--an Eastern with pale, lightly marked underparts (or all the plumage?), seen more on the Great Plains than elsewhere. 

[smittyone@cox.net]

Oops.  Sorry about that.  I just looked for the next shots that showed decent spread wings without looking closely enough if it was the same bird.  Both birds were photographed 9 minutes apart, and this was back in 2015, so I don't remember the exact sequence.  This pic is, I'm 75 percent sure, the same bird.

[Jerry Friedman]

6 minutes ago, smittyone@cox.net said:

Oops.  Sorry about that.  I just looked for the next shots that showed decent spread wings without looking closely enough if it was the same bird.  Both birds were photographed 9 minutes apart, and this was back in 2015, so I don't remember the exact sequence.  This pic is, I'm 75 percent sure, the same bird.

 

Another fine shot.  I agree that that's the original bird.

[smittyone@cox.net]

I'm glad we've identified this bird.  On the downside, now I have to submit every light Eastern Red-tailed Hawk I've ever called a Krider's.  Every one of them, like this one, photographed within 20 miles of the Missouri River (both sides) from Missouri Valley in Iowa down to Mound City in Missouri.  At least Jerry's FB experts will have a few more to mull over.  Almost make me want to re-join Facebook again, no, wait...no it doesn't. 

[Jerry Friedman]

2 minutes ago, smittyone@cox.net said:

I'm glad we've identified this bird.  On the downside, now I have to submit every light Eastern Red-tailed Hawk I've ever called a Krider's.  Every one of them, like this one, photographed within 20 miles of the Missouri River (both sides) from Missouri Valley in Iowa down to Mound City in Missouri.  At least Jerry's FB experts will have a few more to mull over.  Almost make me want to re-join Facebook again, no, wait...no it doesn't. 

No, the ones in migration and winter can still be Krider's.  But the experts will probably be happy to see more birds.

[smittyone@cox.net]

I'm adding this bird to the original post because I'm about 90% sure it's the same bird.  It was photographed in the area five days later.  Do you guys agree?

 

[chipperatl]

There are scoring systems for how much white is on the rump of Storm-Petrels.   Is there some scoring for patagial marks, belly-bands, heads, tails and rumps for Red-tails?  If not, maybe there should be.  

[Avery]

34 minutes ago, chipperatl said:

There are scoring systems for how much white is on the rump of Storm-Petrels.   Is there some scoring for patagial marks, belly-bands, heads, tails and rumps for Red-tails?  If not, maybe there should be.  

There probably is somewhere. I’ve seen it for the White-winged Gulls and for BWWA/GWWA

[Jerry Friedman]

Mike Borlé: As I mentioned the lack of any molt at all, and lack of a thick, dark trailing edge on the flight feathers should be enough to convince anyone that thought this bird was an adult. I'm beating a dead horse a bit here, that's for sure!

Speaking of "for sure", I'm sure the hawk in your excellent new photos is the original one.

Edited March 9 by Jerry Friedman

[smittyone@cox.net]

It seems after a quick review of all of my Krider's hawks, using the above pale "Plains" Eastern (borealis) as a reference, it seem that many, if not most of what I thought were Krider's, have been misidentified.  I'll still post them here just to be certain.

I do still need clarification (in simplified terms) what a "Plains" version of borealis is.  Is it a regional difference, or a plumage difference, or both.  Are all pale borealis considered "Plains-type"?  Because if that's the case, I have A LOT of them in my area.  Is Plains the only sub-subspecies of borealis, or are there others?  

[smittyone@cox.net]

1 minute ago, Jerry Friedman said:

Mike Borlé: As I mentioned the lack of any molt at all, and lack of a thick, dark trailing edge on the flight feathers should be enough to convince anyone that thought this bird was an adult. I'm beating a dead horse a bit here, that's for sure!

Speaking of "for sure", I'm sure the hawk in your excellent new photos is the original one.

Wait...are we talking about the same bird?  I though we'd settled on it being a juvenile.

[Jerry Friedman]

18 minutes ago, smittyone@cox.net said:

Wait...are we talking about the same bird?  I though we'd settled on it being a juvenile.

Same bird, and he's still saying it's a juvenile.  To paraphrase what Mike write, anyone that thought this bird was a adult should now be convinced it's a juvenile.

[Avery]

36 minutes ago, smittyone@cox.net said:

It seems after a quick review of all of my Krider's hawks, using the above pale "Plains" Eastern (borealis) as a reference, it seem that many, if not most of what I thought were Krider's, have been misidentified.  I'll still post them here just to be certain.

I do still need clarification (in simplified terms) what a "Plains" version of borealis is.  Is it a regional difference, or a plumage difference, or both.  Are all pale borealis considered "Plains-type"?  Because if that's the case, I have A LOT of them in my area.  Is Plains the only sub-subspecies of borealis, or are there others?  

I think it is a regional change in plumage following Gloger’s Rule (animals in higher humidity climates are darker than animals in arid climates). It wouldn’t be a subspecies of borealis, since borealis is itself a subspecies. These “plains-type” I think are a way to label birds that are from the “contact zone” between Krider’s and borealis. Red-tails are highly variable, even within each subspecies, especially with such a large range. 

[smittyone@cox.net]

The attached map was borrowed from the redtailedhawkproject.org.  Although not indicated, I presume it depicts Red-tailed Hawk's breeding range.  Based on this map, my birding area in eastern Nebraska southward, put's me in the western middle of borealis territory.  But kriderii range is also within that same range.  Where I typically bird, there aren't any boreal forests or higher humidity regions, where the "darker" versions of borealis should normally be seen.  Therefore, my simplified logic dictates that, except for migration season, most, if not all the Eastern Red-tailed Hawks I encounter should all (or mostly) be Plains-type.  What do I call borealis in my area that aren't the lighter Plains-type?