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Ben's theory about the golden eagle


This week's post is different because it's about someone else's work, not mine. When I wrote about my golden eagle skull a few months ago, I wrote that it had two sets of injuries, one on the back of the head and one on underneath the skull. At the time I thought the first injury was caused by a blow, and the second one underneath was caused a different time by a shotgun pellet.

Ben Garrod, who is a zoologist and skeleton articulator wrote on my Facebook fan page that he had a different theory. This post is about his theory and how I tested it.

Here's a close up of the injury on the back of the skull. It is a long uneven zigzag crack with a small triangular hole at one end:

This injury is the one underneath, on the top of the mouth, which I thought was a shotgun pellet which got lodged there, and the bone had tried to grow around it.

Ben's theory was that both injuries were caused by the same thing, which was an attack by another golden eagle using its claws. He did his own picture to show me but these are the ones I did and how I did them. I didn't have a golden eagle claw, but I did have a buzzard foot and a buzzard skull, which is similar to a golden eagle skull but much smaller. I got the foot from the buzzard skeleton at the Rhynd lochs.

Here's what a golden eagle's claws look like with three at the front and one at the back that you can't see:

A buzzard's claws are almost the same but much smaller. I think they are in the same proportion to the skull as the golden eagles are.

Here are the two buzzard claws I have which I took from a dead buzzard at the Rhynd lochs. The flesh has shriveled up but the size should be about the same because the bones will be the same size as when it was alive. I used the open claw at the bottom to test.

Ben said: "In this sort of encounter i.e. between two argumentative eagles, you would get a single puncture mark on the upper palate and a larger area of damage on the opposite side of the skull in the frontal/parietal region. Also, I've only articulated the right foot so far and it fits in 'opposite' on the skull (with the injuries your skull showed). So I reckon that the attacking eagle hit your bird from about a 45 degree angle with its left foot and sunk its sharp talons in, causing the injuries, which were somehow not fatal". So on the buzzard they would have looked like this:

and that fits the theory for the hole on the bottom. This is how the buzzard claw looks going through the hole in the golden eagle skull.

This is the back of the skull and that also fits with a 'crushing' injury too.

Because of this I think Ben is right although we will never know for sure. It is incredible that this bird managed to escape, but it have must have lived after it because those injuries on the bone have healed.

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Psydrache said...

Yes, to find out the real cause of death or the real cause of injuries is a difficult thing but Bens theory sounds quite plausible. It's amazing how strong the legs, feet and claws of a bird of prey can be!
Anyway, animals can be so strong an tough! I wrote about a polecat skull which had a lot of parasites in it. And if you look at it you would think that the parasites killed it. But thats not true, the polecat was still fit.

Jake said...

@Psydrache: I think Ben's theory is right too.

Jack N said...

Hey Jake!
Just thought you should know you put the alligator head in your "my skulls" section twice.

Jake said...

Thanks Jack ! I've changed it.

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