Cat's World

We can plainly see the cat’s origins as a predator of small rodents in its remarkable hearing abilities remarkable both in the range of sounds it can hear and in pinpointing the source of the sound. The cat is hearing range extends two octaves higher than ours, into the region that because we cannot hear it we refer to as ultrasound. This extended range enables cats to hear the ultrasonic pulses bats use to orient themselves while flying in the dark, and the high-pitched squeaks of mice and other small rodents. Cats can also tell different types of rodents apart by their squeaks. In addition to this sensitivity to ultrasound, cats can hear the same full range of frequencies we can, from the lowest bass notes to the highest treble. Almost no other mammal exhibits such a wide range, about eleven octaves in total. Because cats’ heads are smaller than ours are, their hearing range should be shifted to higher frequencies, so their ability to hear ultrasound is perhaps no...

Cats also show little interest in color; among mammals, color seems a unique primate, especially human, obsession like dogs, cats have only two types of cones and see only two colors, blue and yellow; in humans, we call this red-green color blindness. To cats, both red and green probably look grayish. Moreover, even colors they can distinguish seem to be of little relevance to them.  Their brains contain only a few nerves dedicated to color comparisons, and it is difficult to train cats to distinguish between blue and yellow objects. Any other difference between objects brightness, pattern, shape, or size seems to matter more to cats than does color. Another drawback of having such large eyes is that they are not easy to focus. We have muscles in our eyes that distort the shape of the lens to allow close vision; cats seem to have to move their whole lens back and forth, as happens in a camera, a much more cumbersome process. Perhaps because it is just too much...

Human eyes and cat eyes share some similarities we are both mammals, after all, but cat eyes have evolved as superefficient aids to hunting prey. The wild ancestors of the modern cat needed to maximize the time they could spend hunting, so their eyes enabled them to see the merest glimmer of light. This has affected the structure of cats’ eyes in several ways. First, they are huge in comparison with the size of their heads; indeed, their eyes are almost the same actual size as our own. In the darkness, their pupils expand to three times the area ours do. A reflective layer behind the retina, known as the tapetum, further enhances the efficiency with which their eyes capture light. Any incoming light that misses the receptor cells in retina bounces off the tapetum and back through the retina again, where some will happen to strike a receptor cell from behind, enhancing the sensitivity of the eye by up to 40 %. Any light that misses the second time around will pass ...

We may easily overlook the simple fact that cats live in a world that is subjectively speaking quite distinct from ours. We share just enough overlap between our different perceptions of the world to be able to relate to one another, each species having evolved its senses to fit its lifestyle. It is unreasonable to consider cats’ abilities as inferior or superior to our own. Biologists abandoned the idea of one species being “superior” to another decade ago, though cat owners may suspect that their cats feel otherwise. We now consider each species as having evolved to fit a particular way of life; cats are good at being cats, because their ancestors evolved sense organs and brains to suit that role. Because the domestication of the cat is still incomplete, that role is still in a state of flux, for example, cats are still adapting to urban living while their sense organs have remained more or less unchanged. One major difference between cats and people...