Dark morph fun

[DLecy]

Not seeking an ID as I know what this bird is, but thought I would throw it out there for others to discuss. Dark buteos are challenging...er, I mean fun. Any takers?

Northern CA - 11/8/20

[AlexHenry]

Rough-leg?

[DLecy]

Care to explain your thinking @AlexHenry?

 

[AlexHenry]

Not Swainson’s (underside of flight feathers too pale) not Ferruginous (underside of flight feathers not pale enough, especially at the very tip of the wings). Tail does not look like adult or juvenile Red-tailed Hawk.

I’m not really confident in that ID. Also I have no experience with dark morph Broad-winged Hawks. I find size and shape tougher to judge in photos.

Edited November 26, 2020 by AlexHenry

[AlexHenry]

Oh another thing is that dark morph Froojies and calurus/alascensis Red-tails tend to have brownish and rusty tones. Dark morph Rough-legged Hawks are more grayscale, black and white, not much color or warmth.

[Avery]

Froojies... 😂 

[Connor Cochrane]

I’m not going to discuss this since I know the ID of the bird, but I always enjoy these quizzes, and seeing how people explain their identification. 

[DLecy]

10 hours ago, AlexHenry said:

Not Swainson’s (underside of flight feathers too pale) not Ferruginous (underside of flight feathers not pale enough, especially at the very tip of the wings). Tail does not look like adult or juvenile Red-tailed Hawk.

I’m not really confident in that ID. Also I have no experience with dark morph Broad-winged Hawks. I find size and shape tougher to judge in photos.

How did you rule out Harlan's RTHA?

[AlexHenry]

I didn’t rule out Harlan’s. 

[Tony Leukering]

BWHA

[DLecy]

1 hour ago, Tony Leukering said:

BWHA

BWHA, with that combo of the prominent trailing edge to the wings and that tail pattern?

[Charlie Spencer]

11 hours ago, DLecy said:

BWHA, with that combo of the prominent trailing edge to the wings and that tail pattern?

Does your question indicate you thought it was something else?

[DLecy]

5 hours ago, Charlie Spencer said:

Does your question indicate you thought it was something else?

Correct. That prominent trailing edge to the wing is a trait I have only ever seen in adult BWHAs. Yet, the tail pattern (if assuming BWHA), is that of a juvenile bird...so it doesn't add up. Yet, RLHAs have a prominent dark trailing edge to the wings and adults have a tail pattern commensurate with this photo. 

Single bird photos are notoriously tough to gauge size in, but this bird was a RTHA/RLHA size in flight. Larger than a BWHA. In field, I saw it briefly and snapped some photos, but the GISS on the bird was not BWHA. Additionally, the shape of the bird is RLHA. Long, and angular. Long wide tail, stocky body, prominent head, small bill, and so on. Also, as @AlexHenry pointed out, silvery underwings are a good RLHA trait. Additionally, BWHA in a glide typically have a flat trailing edge to the wing, whereas this bird clearly shows the trailing edge angling back sharply.

I sent these photos around as dark butoes are a notoriously tough ID, and I got some mixed feedback (BWHA, RLHA, and Harlan's RTHA). Eventually I heard back from a number of folks, including some very accomplished birders and hawk watchers. One well known local hawk watcher who has counted BWHA in Veracruz during migration said he felt very strongly that it's a dark-morph Rough-legged Hawk. I agree.

Edited November 27, 2020 by DLecy

[Benjamin]

I don't know how worthwhile my personal opinion to the ID of the bird would be here, so I'll refrain from giving it. But FWIW if the hawk watcher is from Vera Cruz, chances are he/she does not see RLHA often. That said, I'm very interested to hear why@Tony Leukering thinks this is a BWHA

[DLecy]

4 minutes ago, Benjamin said:

I don't know how worthwhile my personal opinion to the ID of the bird would be here, so I'll refrain from giving it. But FWIW if the hawk watcher is from Vera Cruz, chances are he/she does not see RLHA often. That said, I'm very interested to hear why@Tony Leukering thinks this is a BWHA

Interesting thought. Thanks for sharing. My immediate thought is essentially the opposite in that knowing and familiarizing yourself with a species is often the best way to rule out other species. A quick and simple example; out here in the Bay Area it pays in spades to get to know all the different ways a WEGU can look. This helps rule out WEGU when looking at something else and is often a good baseline to judge other gulls by in this part of the country. One could apply the same logic to raptors. By knowing and becoming familiar with a certain species or multiple species, it becomes easier and more reliable to rule that out when you see something different. Simply put, when you have seen hundreds of thousands or even millions of BWHA, you tend to know when one isn't a BWHA.

FWIW, the individual I referenced lives in San Francisco. I have hawk watched with him multiple times on Hawk Hill in the Marin headlands in addition to running in to him in the field a handful of times locally. So, while he has counted in Veracruz, he is not from Veracruz and has seen his fair share of RLHA. 

[Benjamin]

Right, of course that is true, but the comment from that individual was that they felt strongly it was a RLHA, not that it wasn't a BWHA. Regardless, it's a bit irrelevant and was just an offhanded 'FWIW'. 

[DLecy]

14 minutes ago, Benjamin said:

Right, of course that is true, but the comment from that individual was that they felt strongly it was a RLHA, not that it wasn't a BWHA. Regardless, it's a bit irrelevant and was just an offhanded 'FWIW'. 

I hear you, and that is a valid point. To be fair, the individual did give me feedback of why it was a RLHA, but I didn't include it in my post. Link to my eBird checklist with more info included for anyone who is interested.