Dueling Hawks - Ottawa, ON (1 Viewer)

Gillian_M · Jun 15, 2008

While out in a marshy area just west of Ottawa I was treated to an aerial battle between two hawks. The smaller one kept mobbing the larger one. I think I have an accipiter and a buteo, but they were both backlit and I'm not sure what species they are. They smaller one was quite vocal, making a rapid, high-pitched cry that sounded like eck-eck-eck-eck. The larger one was silent.

Can anyone positively ID these combatants through the limited detail visible in these silhouette photos?

Thanks!

cnybirder · Jun 15, 2008

I would call the buteo a dark juvenile Red-tailed Hawk.
Not so sure about the other - probably Accipiter.
Squared-off tail should mean Sharpie but size seems to point to Cooper's.
The one photo it seems to have a Harrier look but I think that isn't it.
One of the other photos almost gives me a Mississippi Kite impression.
But at one photo seems to show the barring of an Accipiter.

[after reading Jim's message I definitely agree on Northern Harrier for the second bird. The apparent size and apparent barring in one photo was messing me up.].

Jim M. · Jun 15, 2008

Hi Gillian,

The "smaller" one appears to be a Northern Harrier. Note in the fourth photo the dark head and throat, and light belly, together with black fingers contrasting with white undersides of wing. These would be inconsistent with an accipiter. Your description of the call also fits for Northern Harrier.

The "larger" one is a buteo, but I am not sure about it. My best guess at this point would be an intermediate phase Red-tailed Hawk (darker on the belly than the typical Red-tail). Others may have additional insights.

Best,
Jim

[EDIT: Posting at the same time as cnybirder].

Dave Hall · Jun 15, 2008

Hi Gillian think you have a Red-tailed Hawk in the forth photo the smaller bird looks long winged this makes me think its a Northern Harrier

cavan wood · Jun 15, 2008

One more for northern harrier and red-tail.

Scott

Gillian_M · Jun 15, 2008

Thanks everyone. The red-tail didn't have a bright white belly and obvious belly band, otherwise it would have been an easy ID.

Norther Harrier had crossed my mind while I was watching the two hawks, but I started leaning toward an unknown accipiter when I saw the photos. One reason is that I've never heard a harrier cry before!

Terry O'Nolley · Jun 15, 2008

The wings on the smaller raptor are too long for an Accipiter.

AlexC · Jun 15, 2008

I must say, I'm SO GLAD to have seen this set of photos! It really does challenge birders on structure, not just field marks.

Agree on an adult male Northern Harrier and an SY (second year, born spring 2007) Red-tailed Hawk. See attached photos.

Photo1 is interesting because it presents a harrier from an angle we don't usually see them - no tilting V, eh? However, no other bird fits - yes Accipiters are known for long tails, but that is long tails with short wings. This higher ratio might point to Cooper's Hawk, but this is quickly discounted by the apparent jutting wrist and equally-lengthed rectrices - both characteristic of Sharpie. :eek!: Reevaluation time. Gillian mentioned marsh. Then we look at field marks pointed out by Jim - black wing-tips, light wings and belly - and I'll add black-fringed flight-feathers and the owl-like facial disc (structurally seen). All these point to not just any Northern Harrier, but an adult male - not a common sight vs. young ones and females!

As for the Red-tailed, after brightening one photo patigal bands/bars and belly-bands can be seen (see attached). SY Red-tailed.

Gillian_M · Jun 16, 2008

Wow - impressive break-down of structure, Alex! This is one of the reasons that I posted these shots, despite the fact that the field marks were barely visible due to back-lighting.

rjackb · Jun 16, 2008

Besides wing length, etc., I have read that another distinguishing characteristic between an accipiter and a Northern Harrier would be that an accipiter has 6 noticeable "fingers" in their primaries while a Northern Harrier has 5. In the first photo the bird clearly has 5 "fingers".

Is it correct to assume that the gaps in both bird's wings is due to the beginning of a molt?

Jack

Jim M. · Jun 16, 2008

AlexC said:
I must say, I'm SO GLAD to have seen this set of photos! It really does challenge birders on structure, not just field marks.

Agree on an adult male Northern Harrier

Nice post Alex! But I think you get excited whenever you get the opportunity to use the word "rectrices".

By the way, I was wondering if this might actually be a subadult male Harrier. Both the head and tail look fairly dark, almost brown. I would think an adult male would be lighter. (Look at plate 141, page 155 in the Eastern Wheeler, for example, if you have it).

Cheers,
Jim

cnybirder · Jun 16, 2008

rjackb said:
Is it correct to assume that the gaps in both bird's wings is due to the beginning of a molt?

Jack

I don't know if it would be the beginning of the molt but it definitely is molting.

AlexC · Jun 16, 2008

J. Moore said:
I think you get excited whenever you get the opportunity to use the word "rectrices".

3

8-P Definitely.

rjackb said:
Besides wing length, etc., I have read that another distinguishing characteristic between an accipiter and a Northern Harrier would be that an accipiter has 6 noticeable "fingers" in their primaries while a Northern Harrier has 5. In the first photo the bird clearly has 5 "fingers".

Decent formula for photos, I guess. You let me know next time you see a raptor in the field and have time to count prominent primaries.

rjackb said:
Is it correct to assume that the gaps in both bird's wings is due to the beginning of a molt?

J. Moore said:
By the way, I was wondering if this might actually be a subadult male Harrier. Both the head and tail look fairly dark, almost brown. I would think an adult male would be lighter. (Look at plate 141, page 155 in the Eastern Wheeler, for example, if you have it).

I think we may ALL be right (crazy, huh?

). Northern Harriers molt throughout the summer: mid-May - early-Oct (per BNA Online). Hence, this bird molting primaries symmetrically. Here is BNA Online on male Basic I Plumage (i.e. sub-adult plumage):

Quite variable. Differs from Definitive Basic plumage (see below) in that head is darker and browner, with the ends of feathers of the occipital spot having tawny margins; dorsum darker, with scattered tawny and tawny-margined feathers; underparts, especially upper breast, more heavily marked, many with tawny tinge, flanks barred brownish sepia. Smaller upper-coverts of wing tinged buffy brown to tawny. Undersurface of primaries with dark bars or irregular marks. Some underwing-coverts with darkish barring. Tail with tawny splotches on outer feathers. At least some males become progressively paler and less tawny over several molts.

I could go along with this bird being a sub-adult starting Definitive Prebasic molt (i.e. molting into Definitive Basic Plumage - adult plumage), mainly because of Jack's suggestion. BNA Online on Definitive Prebasic molt:

Primaries are molted first (inner to outer), then secondaries, then greater upper-coverts of remiges, and tail (inner to outer, except for central pair, which is delayed). Concurrently, new body feathers appear on head and foreparts, then elsewhere.

And as we can see, the inner-most primaries are molting - indicating the beginning of molt. :t:

rjackb · Jun 16, 2008

AlexC said:
Decent formula for photos, I guess. You let me know next time you see a raptor in the field and have time to count prominent primaries.

Hey, just thought I'd mention it. If you're not interested then fine but I don't see the need to discount my observation. The IDs in this thread were made based on posted photos, as usual, so I think there was plenty of time to count prominent primaries.:eat:

Jack

AlexC · Jun 16, 2008

rjackb said:
Hey, just thought I'd mention it. If you're not interested then fine but I don't see the need to discount my observation. The IDs in this thread were made based on posted photos, as usual, so I think there was plenty of time to count prominent primaries.:eat:

Jack

My comment was meant tongue-in-cheek, Jack - sorry if that didn't come across! o

It's a damn good observation - not one I would discount - I just worry about how definitive it is, if you over or under count - photos can catch birds at weird angles, especially if the wind blows one primary into the "counted" finger-bunch.

rjackb · Jun 16, 2008

AlexC said:
My comment was meant tongue-in-cheek, Jack - sorry if that didn't come across! o It's a damn good observation - not one I would discount - I just worry about how definitive it is, if you over or under count - photos can catch birds at weird angles, especially if the wind blows one primary into the "counted" finger-bunch.

Fair enough. Thanks for your response.

Best Regards,
Jack

Jim M. · Jun 16, 2008

rjackb said:
Besides wing length, etc., I have read that another distinguishing characteristic between an accipiter and a Northern Harrier would be that an accipiter has 6 noticeable "fingers" in their primaries while a Northern Harrier has 5. In the first photo the bird clearly has 5 "fingers".

I see more discussion of "fingers" in the European raptor threads, less so in American. Not sure why. In any event, I agree that Harriers do appear to have a distinctive five finger pattern. It appears to be pretty consistent also. But when I look at photos of accipiters, I have difficulty finding a consistent or clear pattern. Perhaps it is because the position of their wings is more variable.

Best,
Jim

JANJ · Jun 16, 2008

Good point to look for 'fingers' in raptor images (provided they are not in moult!) more difficult in the field.

Northern Harrier has 5 fingers. In Europe we have to deal with 4 different Circus sp (harriers), Marsh, Hen (Northern Harrier), Montagus and Pallid Harrier. A first step to eliminate Marsh and Hen from the other two is, among other characters, is that Montagu´s and Pallid has 4 fingers.
Also our Buteo´s (as the N.A ones - except Swainson´s and Broad-winged, 4 fingers) have 5 fingers against 7 in the larger eagles.
The Accipiters do have 6 fingers.

http://www.pbase.com/btblue/coopers_hawk

but depending on in which way the wing appears they can seem to have 5 fingers:

http://www.pbase.com/axelhi/image/85236151

http://www.pbase.com/image/34987661

The silhouette of the Northern Harrier is markedly different from the Accipiters, as can be seen in Gillian´s images!

JanJ

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