Re: birding-aus Neck-swaying White-faced Heron

[kim sterelny <>]

Hi Jill,
        If I rememmber rightly, owls move their head to fixate on prey
because their eyes are not equipped to saccade. Our eyes move in our head
all the time, and this helps not just with stereopsis but also it prevents
retinal cells habituating to an exact visual stimulus. I do not recall the
reference, but I think there is experimental evidence that if you prevent
autonomous eye movements in humans you induce a kind of temporary
blindness. I have no idea whether the same is true of herons, but if I had
to guess, that would be mine.

Kim
Kim Sterelny
Philosophy
Victoria University of Wellington
PO Box 600, Wellington
New Zealand



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