And, don't identify hawks by this trait alone…several of them can show it. It was believed years ago that it was a good trait for perched Rough-legged Hawks (below), but I have seen too many Red-tails (below) and a few other buteos show this. These are just a few examples, including this male Harrier (below) with a neat pattern they typically show. THESE SINGLE SPOTS ON SOME HAWKS REALLY DON'T RESEMBLE EYES, but just wanted to make a point.
Rough-legged Hawk
Red-tailed Hawk
Northern Harrier
10 Comments:
Jerry, Just a couple of observations from a rank amateur. I guess I never thought of the single, central spots on the backs of the heads of hawks as eye spots. I've often wondered about the rusty spot on the male harrier in particular and I've tried to look it up and struck out (even BNA in their extensive description of "definitive basic plumage" doesn't mention it). I guess I've always thought of the double spots on the back of the head of kestrels as more like "eye spots". Any thoughts? (I'm here to learn...)
No, I agree with you Ron, I don't consider these eye spots but just wanted to bring attention to the fact that birds have been identified by this spot alone and it is dangerous to do so. What do you think the eye spots on Kestrels and Pygmy Owls serve? I've heard theories but want to hear what people have to say.
Also, watch out for the term "definitive basic plumage", this term is misleading in regards to many birds, but accurate for others
I've heard some of the same theories, Jerry but in the case of kestrels and Pygmy Owls I'm unconvinced (though it is possible). I think similar "eye spots" found on the rear of the body of some other animals (certain insects, for example) make more sense as a "head decoy" so the potential predator goes for the "wrong" end and allows the potential victim to possibly escape or defend itself. Who knows, though...
Exactly Ron....
For a predator that is fearful of anything directly behind them and is hardwired to react to what they see, and is constantly looking around and behind it, I don't think "eye spots" serve any purpose at all. As a decoy, or identification. They don't even look like eyes. I agree with you guys in saying that trying to identify a raptor based on those spots is futile. Its like trying to figure out what falcon you're looking at by looking at a silhouette and wing shape alone. But it's an interesting trait that raptors share. Its like black wingtips on almost every species of North American Raptor,(btw I know why they're black but that's a different subject) but to try and guess what purpose "eye spots" have is a waste of my energy in my opinion.
Thank you Jerry, enlightening since I've never seen a Red-tail with that spot that I associate with Rough-legged Hawk.
I learn so much from your blog, thank you.
I have often wondered about these "eye spots" especially in Roughies. And, dare I admit that on more than one occasion I have had to take an extended period of time to decide if a Kestrel is actually looking at me, or looking away, or looking left, or right or ...? Each time this has happened I have been a long distance away looking through a camera lens. Because of this I have always thought the "eye" serves some kind of decoy purpose to other animals who might spot the bird from a long distance away. Up close, we all can see that it's not an eye, but from far away, it's harder to tell. For what purpose this is, I don't know, but I have always thought this "eye" had something to do with distance. Just my .02!
Thanks Jennifer, and that is one of the theories behind the eye spots, that predators believe the kestrel can see them. And I think that's a good theory for the smaller birds like Kestrels and Pygmy Owls
Please keep commenting whenever you want!
I've heard the eye spots also referred to as "ocelli," and, because they are found on smaller raptors, assumed that they functioned strictly in warding off predators. Negro et al. (2007) (link below) present some interesting alternative hypotheses, but I'm not sold on their conclusions.
http://tinyurl.com/kgtnemo
Thom -- Thanks for the link to the paper. Cooments like this are great and the prurpose of my blog!
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