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Discussion of other Raptor species; their anatomy, biology, ecology, etc.
Topic Started: Sep 16 2007, 11:04 AM (18,113 Views)
Raptorman
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Bea
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Yes Bill, I do have a more recent version of both, the Field Guide as well as the Complete Birds of North America. BTW, The Field Guide version makes no mention of eyecolor being related to gender.
Thanks for looking into this!
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Raptorman
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Bea
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The "Complete Birds of North America" has more info on each species. The pictures/drawings are in most cases the same in both books, but the "Complete" goes into more detailed descriptions. It is a bigger book than the Field Guide, and on the front cover it says it is the "Companion to the Field Guide".

I looked at the descriptions for both, the Coopers and Gos.

The Gos only mentions eyecolor as "Red Eye" under the description for the adult.
No eye color description is given for the Juvie Gos. No mention of gender relating to eyecolor on either Juvie, or adult.

For the Coopers the Adult description reads "Eye color is orange to red".
No eyecolor description is given for the juvie Coopers. No mention of gender relating to eyecolor on either juvie, or adult.

The Sharpie reads:
For the adult (as mentioned previously): "The eyes are red-orange (females) to deep red (males)."
For the juvie Sharpies: "Eye color is pale yellow"

Another observation: The general "opening" description for the Sharpie states: "Sexes look alike, females are larger than males, adults differ from immatures." Interesting.... on one hand they say sexes look alike, but then they have a definite distinction between the adult sexes when describing eyecolor :blink:

And another observation:
In the "Complete Birds of N.A", every new section starts with a general description of that genus. Under the "Accipiters" it states: "...All start out with yellow eyes as immatures, changing to orange, then red."

Some interesting stuff we stumbled across here! Curious to hear what Patti's books have to say. :D

All quotes were taken from "National Geographic Complete Birds of North America" published 2006.
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Raptorman
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ostrich2
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Raptorman,Dec 16 2007
12:05 AM

There is a distinct difference in the tail shape between the Sharpie and the other two N.A. accipiters. The Sharpie's individula tail feathers are of such a length to create a "square" or straight lined appearance. While the Cooper's and Gos outer feathers gradually get shorter to create more of a curved appearance.

Don't let these two species frustrate you. They are challenging to many birders. Bill :D

Does this mean when the bird has its tail setting straight? Even though both the Coopers and the sharp-shinned are described has having narrow squarish tails, it certainly makes a big difference when they fan their tails out, as we saw in one of Bea's photos.

No frustration here - I'm happy enough that I got the species right :D I never did figure out what some of the photo id video birds were. Although based on this last exercise I think I would change my answer of the first bird in the set from sharp-shinned to Coopers.
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Bea
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Ian, I think you did great with your ID and reasons for it on the Sharpie! I had the added bonus of seeing it live, as well as in many more pics than you have, and I still wasn't 100% sure either. I think we have definetly made progress (I know I have :lol: ). All three of us got the species right!

Patti, I'm sorry I overlooked another of your questions to me. You were wondering about the American Kestrels. Yes, I do see one over the School sometimes (not sure if it's the same one every time), and he usually lands on top of that big big Pine Tree that's there. I have a spotting scope (bought at Sarah's yard sale from Jeannette) and we can see it real good thru that.
But, if you want to increase your chances of seeing a Kestrel, try the Lake Casitas area. I don't see them close to the lake, but if you take some of the roads around the lake, keep your eyes on the power/telephone poles and lines. You'll see one sooner or later along with a great number of Hawks and Kites. Ojailala posted some great shots of some Turkey Vultures and other birds over in Chat today. Check it out! I love the Lake Casitas area. There are many many different birds there. In spring this year, I saw for the first time in my life a great blue heron with baby. And not just one, oh no, they nest there every year and there are a lot of them. Just awesome.
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Patti
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Sorry for jumping in late on the eye color/gender topic, but I have some experience with Umbrella cockatoos. I kept 3 offspring from my now non-breeding parents. All three (Bea has seen them) have the color of a Lindsay (sp?) type canned olive when viewed in sunlight. They're a dark but warm charcoal, but not black.

Mom Umbrella has classic reddish eyes in the sun--dad's looks more like the offspring--but his are probably darker. Alger and Joy, two of these offspring, have both laid eggs. AJ has not laid eggs, but pants when I hold her (has not been sexed) and has not exhibited the classic male mating behavior that we don't need to discuss here. :rolleyes: :lol: :wub: You get the idea. My African grey and cockatiels demonstrate this all the time, so you generally figure out what you have once they go hormonal.

The point: For years psittacine people were told that male Umbrella cockatoos had dark eyes and female had reddish eyes. Bea has seen my dark-eyed girls--and I suspect all are female, AJ included.

I've lost my place here with posts, but see I'm going to check on something in my Brown & Amadon reference book for Bill. And have room-moving/switching chores too..so will be back.
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ostrich2
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Raptorman,Dec 14 2007
01:55 AM
The Prairie Falcon "enjoys" a lower profile in falconry and the general public partially because of the much more popular Peregrine (easier to train) and the larger Gyr. Prairies enjoy a greater following within their natural range and I'm guessing in the U.K. because the Peregrine may have protected status or import/export issues with the U.S. Don't underestimate the effect of the Peregrine being a much easier (more stable mentality) species to train. Inexperienced falconers are better suited to the Peregrine and with the increasing access to hybrids the Prairie has unfortunately often been put on the back self.

The Swainson is simply not capable of the variety of prey species as the Redtail. They also don't have nearly the range and therefore accessibility for falconers. (Many states have regulations not allowing capture of raptors by nonresidents.)

Of course none of this means we can't discuss either of these species here. :lol:  Bill

The only thing I really know about the Swainson's is that

The pattern on my underside is just reversed
From all the buteos you have rehearsed
My long pointy wings keep me on the go
As I make my way to Tierra del Fuego


Doing a little bit of searching, one thing I came across is that the Swainson's is a frequent insect eater, which I haven't heard of the other hawk species doing. I imagine catching grasshoppers or crickets wouldn't be that exciting for falconry :D

I know the prairie falcon strikes fear into the rodent's hearts :D
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Raptorman
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Raptorman
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ostrich2
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That is awful about the Swainson's - and a serious problem and issue when migratory species end up moving to areas that do not have the same environmental regulations and protections that might exist in the US/Canada.

It's interesting that buteos would eat insects - you would imagine going after food as tiny as insects would be something accipiters would do more than buteos, the accipiters being more agile and adapted for going after small bird and mammal prey already. Now I have to think a bit about how the energy availability/expenditure equation that we were discussing earlier would work for the buteo in this situation :D

Have you worked with the Swainson's or the prairie much? Any interesting stories to tell about these species?
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Raptorman
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ostrich2
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Here is a news story that was posted about a young peregrine rehabilitation and release in Brisbane - the article says that this bird is thought to be the one which fledged from the Brisbane cam, although I'm not sure on what basis that hypothesis is based. There is a video as well which shows the bird's release:

Young Peregrine Release
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Raptorman
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