Stereoscopic vision on birds (1 Viewer)

Hello, I would like to comment a topic that I sometimes ask myself. It is related to the stereoscopic vision of birds.

Most birds of prey have frontal eyes, so they can appreciate distances, something necessary to locate and easily catch their preys. This is particularly evident in nocturnal birds such as owls, etc. Day birds of prey have their eyes more laterally, but I think they can bring together the two fields of view to get a stereoscopic vision.

However, most birds have their eyes on the sides of the head, so that they look with one eye to stare at something.

Now, the birds move in their flight in a three-dimensional space, where the appreciation of distances is fundamental. For example, a flying sparrow can accurately perch on an inner branch of a tree, for which it must perfectly perceive distances to distinguish all branch details that surround itself.

How do those birds manage this by looking with their side eyes? Do they have any different mechanism from ours to distinguish distances?

Best regards
Rafael

All birds have some overlap at the front. Some, notably Woodcock, also have some overlap at the rear, with each eye covering about 190° (hence the 'bulging eyes' appearance!) with 15° overlap at the front and 5° at the back - nice all-round vision.

Thank you Nutcracker for your reply.

Probably birds have at least two foveas on their retine. The fovea is the area of the retine with greater visual acuity. Because some birds stare laterally at distant objects and frontally when pecking food. (It's just an assumption).

Rafael

Thank you for this interesting subject. There is a pretty good article on bird vision in wikipedia. You're right, in "54% of birds, including birds of prey, kingfishers, hummingbirds and swallows, there is second fovea for enhanced sideways viewing."