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Canada, Alberta, outside of Calgary - Dark morph Hawk (1 Viewer)

KhostAdenplusmore

Well-known member
Hello,
I was walking on a cool misty afternoon in August west of Calgary. I had a dark morph hawk fly above. There was not alot of light to reflect and allow good views of the bottom of the bird, but I felt it could be a dark-morph hawk. But whether it was a Red-tail, or a Swainson's, or perhaps a Rough-legged hawk I was not sure.
Any ideas what this hawk might be? (I have boosted the exposure of this photo significantly)
thanks,
z
 

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njlarsen

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Agree with Swainson's. There is no dark patagial mark and the flight feathers are really dark.

Niels
 

KenM

Well-known member
..unbarred dark fingers, pale base outer primaries; pale vent (exclusive feature!), really smallish bill

Yes good to know, I hadn’t appreciated that the tail on Swainson’s was shorter than the body, a feature I normally attribute to RTH not unlike European Common Buzzard.
Although probably a more regular feature on Swainson’s, am unsure that it enjoys a monopoly on the contrasting pale vent, the front cover of the Audubon Sibley guide to birds shows Red-tailed Hawk...with just that!

Cheers
 

Valéry Schollaert

Respect animals, don't eat or wear their body or s
Yes good to know, I hadn’t appreciated that the tail on Swainson’s was shorter than the body, a feature I normally attribute to RTH not unlike European Common Buzzard.
Although probably a more regular feature on Swainson’s, am unsure that it enjoys a monopoly on the contrasting pale vent, the front cover of the Audubon Sibley guide to birds shows Red-tailed Hawk...with just that!

Cheers

Ken, all Buteo have such a short tail, RTH, CB, etc ; about 1/2 or 2/3 of body length.
 

ceasar

Well-known member
Yes good to know, I hadn’t appreciated that the tail on Swainson’s was shorter than the body, a feature I normally attribute to RTH not unlike European Common Buzzard.
Although probably a more regular feature on Swainson’s, am unsure that it enjoys a monopoly on the contrasting pale vent, the front cover of the Audubon Sibley guide to birds shows Red-tailed Hawk...with just that!

Cheers

The length of the wings of Swainson's Hawks are best seen on perched birds. The wing tips can be as long as the tail length and often extend past the tail tip.

There are many photographs of Swainson's Hawks in Wheeler's "RAPTORS of Eastern and Western North America" showing this.

Bob
 
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gerdwichers8

Well-known member
Actually, the tail length is not always appreciable as longish for a buteo spec. But when a perched bird is looked upon (in profile) many individuals slightly project their handwing against the tail or they fall equall (only in juv. the wing falls short).
So exact measurements should reveal the tail to be long as it comes along with the long wing.
 

gerdwichers8

Well-known member
..the handwing is most easyily seen as long. The wing in full might be problematic but one could look upon the smallish head, which perhaps indicates the large proportion of the wingsurface against the rest of the body.
In an European context the long handwing of a perched bird will appear like an ornament since the observer is likely to be unaware how a Swainson's flies. It will compare to e.g. those of a Redfooted Falcon or a Montagues Harrier
 

ceasar

Well-known member
On page 278 of Wheeler's Western Edition there is a long 2 page chapter about the MOVEMENTS(Migration) of the Swainson's Hawk. It is too long to go into in detail but a short comment is interesting.

"Canadian birds may travel 7,000 miles (11,500 km) each spring and fall to wintering areas in Argentina." (It is noted that the main wintering area is in Northern Argentina)

"Among raptors, Swainson's Hawks are surpassed in migratory distance only by "Arctic" Peregrine Falcons (Falco peregrinus tundrius)"

"Southward movements may begin in late Aug. However, as far north as Alberta it is common to see family breeding groups on their breeding territory until mid-September." (There are comments throughout on the use of telemetry data in the tracking.)

Bob
 
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gerdwichers8

Well-known member
Although probably a more regular feature on Swainson’s, am unsure that it enjoys a monopoly on the contrasting pale vent, the front cover of the Audubon Sibley guide to birds shows Red-tailed Hawk...with just that!

Cheers

since some raptors may come in morphs and others may be uniform dark alltogether, there is no intermediate morph in RTH that does not show a pale vent or a dark morph that does.
 
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