Snapshot Serengeti Talk

Predator eyes

  • tillydad by tillydad moderator

    Predators do have some colour vision, it is mainly blues and greens that they can perceive during daylight hours . They all have better night vision than we do because of the mechanics of their eyes . The lion, for example, can see circa eight times better in the dark than a human can . They have more rod cells than cone cells and the rod cells are light sensitive photoreceptors, whereas cone cells are colour receptive . They also have many more rod cells than we in the fovea, the most light sensitive area of the retina, and this means they only need 1/6th of the light that humans need to see in. They cannot see in total darkness, but there is sufficient light from the stars and moon for these rods to work .

    Furthermore, they have a layer of cells behind the retina, known as the Tapetum lucidum, that reflects light that passes through the eye and is then absorbed by the rods further enhancing what they are able to see in low light levels at night . These Tapetum lucida are responsible for the eye-shine that we see when the flash captures an animal at night . Many animals have, to varying degrees, these reflective cells .

    There are also some features outside the eye that further enhance night vision of leopards and lions . They have white strips beneath the eyes that reflect faint light back into the retina . Cheetahs, daylight hunters, have a black strip beneath the eyes that cuts down on light entering the eyes by absorbing some of the glare that is present during the day .

    Many animals also have the ability to see in ultra-violet wavelengths .

    Hope that this makes sense 😃

    Posted

  • Babyballerina by Babyballerina

    Interesting. So zebras are not very camouflaged really. I think domestic cats have improved night vision so they can locate sleeping humans and attack when they want food/attention!

    Posted

  • tillydad by tillydad moderator

    The stripes of a zebra are not thought to be much use as camouflage . See discussion Zebra stripes for further information on this fascinating subject 😃

    Posted

  • maricksu by maricksu moderator in response to tillydad's comment.

    Thank you Tillydad for this great, interesting article, so great to learn about these things! 😃

    I thought it woud be nice to also add here, how the placement of eyes affects their sight comparing predator-prey.

    Predators have forward-facing eyes in front of head. That gives them good binocular vision that they need in hunting to judge distances, focus on target and e.g. if climbing in trees.

    Prey herbivore animals, e.g. zebra and antelope eyes are situated on the sides of head. Their binocular vision is limited, but side and ”rear” vision good, giving them wide view to detect predators from various directions.

    (One exception in Serengeti antelopes is small agile Klipspringer, living in rock kopjes and other rocky terrain. It has very good binocular vision with it’s forward set, wide eyes and narrow muzzle. Binocular vision is needed, when jumping from rock to rock.)

    Pupil shape also is linked to animal’s role as predator or prey and supports both lifestyles.

    Zebra and antelope pupils are horizontal, helping even more to detect predators from eye-corner when e.g. grazing and give horizontally panoramic view to run fast in uneven terrain.

    In predators pupil shape is more variable from vertical slit to round. Their hunting style (more ambush or active chase down), how active they are day and night, how close the ground they move etc . affects, which is most suitable. In cats, many small cats have vertical slit, but big cats e.g. lion and cheetah have round pupil. 😃

    Posted

  • tillydad by tillydad moderator in response to maricksu's comment.

    Thanks for adding this, @maricksu . You are absolutely right that eye placement plays a vital role for both predator and prey . Evolution never ceases to amaze me ! 😃

    Posted

  • maricksu by maricksu moderator in response to tillydad's comment.

    Thank you Tillydad! I agree evolution is absolutely amazing. It is so nice to learn about all kind of these things and it also helps us to understand a bit more about the animal behaviour we see, when identifying these wonderful animals 😃

    Posted

  • tillydad by tillydad moderator in response to maricksu's comment.

    There is just so much to learn about all of the animals that we see here on SS - and more and more information becomes available as time progresses and scientists delve deeper into all aspects of animal physiology, behaviour etc. 😃

    Posted