Saturday, February 5, 2011

Pop Quiz! White-Winged Crossbills, Accipiter Hawks & Northern Hawk Owl

A crookedness of White-winged crossbills, males and females, Phippsburg, Maine



Sharp-shinned and Cooper's hawks, both accipiters, clock-wise from bottom left: Cooper's, Sharp-shinned (perched), Cooper's (perched), Cooper's (flight), bottom right - Sharp-shinned (take-off)

"You got a problem with this?"
Northern-hawk owl, perched, flight and eating White-winged crossbills in  Bristol, Maine
White-winged crossbill feathers, probably female, aftermath of Sharp-shinned hawk attack. Note that at the mid right of the image above the blood mark is a crossbill bill.

     I love pop quizzes, but most of the people I know hate them. I think that's because people don't like being put on the spot. They like lots of advance time to study and prepare answers so they don't look stupid. Me? I'm quite willing to look stupid without any advance notice required. The images above are of Sharp-shinned and Cooper's hawks, a Northern Hawk owl and White-winged crossbills, pre and post mortem. Do you know what they all have in common? And don't say "Ya, the one on the bottom is dead." That would be just stupid. The hawks and the hawk owl are three species of predatory birds that eat other birds. They all eat White-winged crossbills when they can find them. The Northern hawk owl isn't a hawk at all, though it does behave like a hawk. And, the owl and the White-winged crossbills have more in common than the hawks or the owl. Don't you wish you had studied for this exam?
     White-winged crossbills and the Northern Hawk owl are boreal irruptives in the southern part of Maine.  Neither bird is migratory, but they both occasionally fly south of their usual range when competition for food is too high. In 2007, a White-winged crossbill was found dead in a parking lot in Florida. No one knows for sure how it got there, but it's safe to say it didn't fly. One theory is that it had been hit by a recreational vehicle then rode to Florida stuck in the vehicle's grill. It just fell off in the parking lot on arrival.
     Food supply of the White-winged crossbills and Northern Hawk owls can drop if there is a 'crop' failure or reduction in prey population. Crossbills eat seeds. Their bills are highly adapted for prying seeds from the cones of conifers of the northern forests. The bill holds the cone or seed hull open while the tongue plucks the meat out. I once knew a heavy smoker who could flip a lit cigarette butt around with his tongue so that the lit end was inside his mouth. He would close his lips and blow the smoke out of his nose. Because I knew the guy personally, I thought it was a cool trick. Remember the legendary woman who could tie a Maraschino cherry stem into a knot with her tongue. There's always some guy who says he knew her in high school. White-winged Crossbills with lower mandibles crossing to the right are three times more common than those with lower mandibles crossing to the left, like people that are left handed.
     The birds in these photos were enjoying black oil sunflower seeds in my feeders ans spillage on the ground. Individual White-winged Crossbills can eat up to 3,000 conifer seeds each day. Crossbills breed opportunistically throughout the year whenever food is sufficient for the female to form eggs and raise young. The species has been recorded breeding in all 12 months. A group of crossbills are collectively known as a "wrap" or a "crookedness" of crossbills.
     Northern Hawk owls, also called simply "Hawk owls," are unique among owls. They have long tails and pointed wings and their flight is like accipiter hawks. In addition, they tend to bob their tails when perched and are adept at hovering like kestrels. Their long tail distinguishes them from all other owls. This owl is about the size of a crow.
    Hawk owls eat rodents, mostly voles and in the winter, other birds. They will occasionally take a frog or even fish! Diurnal hunters, Hawk owls like the hawks they are named for, sit on perches and swoop to the ground for prey. They hunt mostly by sight and can see prey up to half a mile distant. Like a true owl, they also can hear rodents under as much as a foot of snow.
     The Hawk owl in the images above was dining on a female White-winged crossbill.  Both of these species were irruptives in Maine in the winter of 2009. This year, there are plenty of White-winged crossbills here, but so far, no one has reported a Hawk owl this winter. Maybe if they knew the crossbill delicacies were here they'd come around. In 2009, it was reported that several times, people who saw the owl took fat, Petco rats for the Hawk owl's pleasure. The owl swooped from its tree perch and snatched up the bewildered, rotund rats before you could say "White-winged crossbill!" Though the owl clearly found the domestic rats tasty, it was regarded as an outrage in the birding community to feed the starving bird that was far, far from home. Perhaps the crossbill that wound up in Florida perished in pursuit of an Early Bird Special after it wasn't allowed into a restaurant.
     Sharp-shinned and Cooper's hawks are accipiter hawks built for speed, because like the Hawk owl, they hunt other birds in flight. Nailing a rodent to the ground requires speed and power, but not flight maneuverability. Both species of accipiter hawks are winter regulars in Maine. When there is thick snow cover, they stalk feeder birds, as easy pickings as a senior citizen's buffet or a Petco rat. Pass the tartar sauce and the Pepcid, please.
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36 comments:

  1. Very cool information...I love bird watching and think it is time I tried snapping some photos to share. I love your pictures.
    Lunchlady 2
    February 05, 2011 11:29 PM

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  2. Love birds and love this post dear. keep 'em coming...
    Mission
    February 05, 2011 11:31 PM

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  3. Wonderful photos. I've got a Disney mind and hate that we have to eat each other to live.
    Jan Sand
    February 06, 2011 04:56 AM

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  4. Jan, I love that line,"Disney mind!" I have somewhat of a Disney Mind myself. Thank you for reading and your compliments and comments. And, Mission and Lunchlady, thank you both, too. I think it's pretty impressive that I live in a place where I can take all of those photos and connect them in an informational story line. It's a wonderful thing when I inspire someone else to take photos, or go birding or anything, for that matter. Thank you all.

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  5. I do a bit of photography with a lousy camera - years ago I had a great film Nikon with great lenses and I am very much amazed at the fantastic precision of your pictures.
    I am doing a blog on my sympathies for an onion.
    Jan Sand
    February 06, 2011 07:52 AM.

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  6. What beautiful collages, and what a lot of thought you put into this remarkable post. It took me a long time to accept the fact that hawks eat other birds.

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  7. thanks much KaHolly. I like the collages because I can get more images on a page and capture ID and behavior elements of the subject. I'm glad they work for you!

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  8. I'm so glad I read your latest blog,I thought a ferral cat had eaten a chicadee next to our porch.Now I'm sure it was a hawk of some kind.The remains looked just like the one you posted.
    Great shots (as always) Robin!!

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  9. Robin, I'm a birder who (like some others) believes that winter locations of rare Owls should not be posted to the community in general. It's not because we don't want people to feed them, but because we don't want people to harrass them. A few years ago (2008 I think) there was a very sad and well-documented case of a Great Gray Owl which basically starved to death because the horde of birders who came to see it would not leave it alone. They literally hounded it to death, though many thought they were doing it a service by bringing mice, etc.

    Owls generally know how to find food on their own, without human help. Because they hunt by hearing their prey (with some exceptions including the NHO, which also hunts by sight), a bunch of birders socializing with each other anywhere near an Owl means that the Owl can't effectively hunt.

    Winter owls are awesome. But I believe that if anyone finds one, they should document it, maybe invite a few close friends to see it, and NOT post its location. The well-being of the owl is always more important than an 'X' on someone's checklist or a photo souvenir. And while most birders are respectful of the bird's right to privacy, an open posting of where a winter Owl is located will inevitably draw some boorish, stupid people (I've seen it for myself).

    BTW nice photos and great article.

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  10. bmc, thanks. glad to be of service. next time you see a feather pile, call me and I'll come photograph it. Never know when it might be useful information.

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  11. Mike, thanks for the read and the info and taking the time to post this thoughtful comment. I agree with some of your points, but not all of them.
    First, I agree that any sighting, even the common place, should be documented and where it will count. Cornell Labs Orinithology data site, eBird is a great place to do this.
    If the birding community had kept the info about the above referenced NHO secret or within the inner circle of birders, I would not have seen it. Subsequently, I would not have had the opportunity to educate others as hopeuflly, I have done here. I object to any elements of birding which are exclusionary and therefore, eletist.
    I do understand fully the risks inherent in telling ANYONE of a rare bird's location. But, I strongly object to the idea that there is relative value among birders as to who gets to know and who doesn't.
    I'm never going to be the best birder because I'm not an academic; I am a generalist in regard to our natural world. I believe that, nonetheless, I have a great deal to contribute educationally and by increasing awareness about any of the subjects I write about. My audience tells me this often. Had the "best" birders been the only ones in the inner circle of information aboubt the location of the NHO, I would have been excluded. Therefore, so would my readers.
    Thank you for the opportunity for this dialogue.

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  12. Interesting. I had an accipiter drop by last week for a Redpoll snack but it didn't have any luck while I was watching. Surprising, considering there were so many it should have been able to hit one just flying through the mob.

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  13. We just arrived in Florida today and we'll keep our eyes opened for another white-winged crossbill on the grills of the "Snowbird's" cars!
    HG
    (Not to rub it in but it was 76 degrees here when we arrived!)

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  14. Hi Robin: Just checked out your blog for the first time. Great pics. I wish Ihad reliable WWCR in my yard! Thanks for sharing. I am guessing you would like to know about a few mislabeled photos.Your raptor sequence should be: 1. adult COHA - correct2. adult SSHA - correct3. immature SSHA, no coop because of the spindly legs, small head andheavy streaking below4. if forget this one but it was an Accipiter in flight5. adult Broad-winged Hawk - by proportions and wide tail-banding Cheers,Eric

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  15. Thank you, HG. I hope you're wearing sun screen down there. If you find a White-winged or a Red crossbill on a car grill, be sure I'm the only one you tell, okay?

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  16. Eric, thanks for that. The ID of the 'bird in question' in the middle frame of the collage, which I called a Cooper's, was made by notable members of the Maine birding list serve, as was the bird in take off stance at the bottom right of the frame. Hhhhmmmm. Sure leaves a slob like myself scratching the old noggin. For those of you who don't know, Eric is the staff naturalist for Maine Audubon at Gilsland Farm in Falmouth, Maine. I'm confident that as such, he is correct in the bird identifications. Thanks, Eric!

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  17. What a great collection of photo's. I checked out your picasa albums too. Awesome photography there.

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  18. Awesome post, Robin, packed with a lot of new to me info. Wished we had more crossbills here. They are quite rare; I keep looking but havent' yet seen one. Enjoyed your photos of the crossbills, the hawks and the owl.

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  19. Thank you, Pin-feathers and Hilke. If you want to check out some pretty decent photography, go to http://robinrobinsonmaine.smugmug.com that's where my best work resides. Hilke, interestingly, we get White-winged but not Red Crossbills anywhere near as often. In fact, I've yet to see a Red crossbill at all.

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  20. Thanks, Robin,
    I enjoyed that - I always learn something

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  21. I forward your blogs to my friend Penny who works with the VT. Land trust to converve farm lands here in Vermont and is a huge nature lover - she told me and I told her I'd pass this on that the lady who can tie the cherry stem in her mouth is not a myth, Penny can do it !!!

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  22. Bonnie, my husband and I almost fell off the couch laughing at that! He thought he was the only one who knew the "knot tie-er!"

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  23. truely stuning pictures of some beautiful birds,i look forward to following your blog

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  24. topshot photography, thanks very much for the glowing praise. Hope I can live up to that!

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  25. A very interesting post and it's great to be able to learn about birds from your side of the world.

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  26. Mick, thanks for that. I like to look at images and blogs from folks across the planet, too. It does make me lust for birds I'm never likely to see, though. That's a certain kind of torture!

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  27. Your photos are fantastic! And your information interesting. Great post!

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  28. Thank you very much, Constantwalker.

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  29. And EmptyNester (great user name!), thank you, too. I hope you all come back, too.

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  30. Awesome kenetic post with great pictures. You are the king of stream of thought prose! What a ride....;-)WBW

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  31. Hey, hey, hey Springman! Woweeee who wouldn't love this, "King of stream of thought prose." Awesome and thank you!

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  32. What an interesting post! Nice collection of photos too!

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  33. Excellent photos--Would love to add the crossbill to my list-

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  34. Thank you,Sondra. Glad you liked them.They are dandy birds. I'll call you when they come back. :)

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  35. Kaepora! That owl is so totally Kaepora Gaebora! (Pop quiz! Anyone here know who that is?)

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