do bird visual fields overlap?

lbarea at waikato.ac.nz lbarea at waikato.ac.nz
Tue Jun 1 18:23:27 EST 1993


Some birds do see in sterio, eg. birds of prey have eyes that face forward
giving binocular vision and associated perception of depth of field needed for
making accurate strikes at prey at speed.  Some birds do have eyes more
laterally positioned eg. passerines- it is an advantage if you are a
potential meal to have a wider filed of view. The woodcock is an extreme
example with 360 degree vision.  I have watched gannets here in New Zealand
foraging.  It is quite apparent that they are orienting the head forward and
down in the manner of a bird of prey.  Compare this with a sparrow with
laterally placed eyes and the cocking of the head to one side when observing
food items.  Natural selection is likely to have favoured sterio vision in a
predator such as the gannet where accuracy is important in obtaining prey.



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