Friday is cat day here, for now, for as long as I keep it up.  Anyway, aren’t they sweet?  Yes they are.  What follows is a steal of a bit from Stephen Budiansky’s book The Character of Cats.  I particularly like it when he says “this is what graduate students are for “.

There are certain habits of domestic cats that are ineluctably solitary. No matter how sociable and friendly they may be toward other cats and people, cats always hunt by themselves. And like all animals that evolved to be solitary and territorial, cats have strongly instinctive methods of advertising their territory.

Fighting is costly for both winners and losers, and so it usually pays to avoid a fight. As a result, these advertising schemes are often highly elaborate and designed to allow occupants of adjacent territories to stay out of each other’s way. Birds that announce their territory by broadcasting songs have a remarkable ability to judge the distance, and sometimes even the age and size, of a potential rival through the tonal characteristics and patterns of his song. Likewise, the urine and feces of territorial animals often can be read by other members of the species in remarkable detail. Odors convey information about the individual identity, sex, dominance status, and estrous status of the animal that left them; and apparently in some cases can even indicate how recently an animal passed through the area.

People often think of animals’ territories as the equivalent of a chain-link fence demarcating a suburban yard; and it is true that the urine marks left by territorial animals often tend to be more frequently found along the boundaries of their range. Likewise, birds that announce their territories with songs tend to focus their vocalizing along the edges of their territories. But in fact most territorial animals that use urine and feces to establish their territories mark throughout their range; boundaries just happen to be the places where they are most likely to encounter a stranger or a stranger’s scent marks, which often trigger their own scent-posting responses.

Cats, both male and female, spray urine frequently on prominent vertical objects throughout their daily travels. Actual observations of the marking behavior of free-ranging cats (this is what graduate students are for) noted that females sprayed on average once an hour, toms a dozen times an hour. Males often mark an object every 5 meters or so along a path. When spraying, cats raise their tails at a 45 to 90 degree angle and aim the urine in a fine spray, typically at a tree, post, or other upright object. This posture is markedly different from the one cats use when simply emptying their bladders; then they just squat. Also it appears that when spraying, cats release a distinctive scent into the urine stream that is not present otherwise.  Experiments have shown that cats will spend more than twice as much time sniffing sprayed urine versus ordinary cat urine.

The particularly characteristic smell of the sprayed urine of tomcats has been identified as the product of an amino acid appropriately named felinine, a sulfur-containing compound.  Members of the cat family are the only mammals that excrete this compound in their urine. Like territoriality in general, the spraying of felinine seems to be triggered by testosterone; intact tomcats excrete about three times as much as castrated males, and about five times as much as females. Chemists who have artificially synthesized felinine in the lab have found that the pure substance actually has no smell, but after being stored for a while it develops a noticeably “catty” odor, apparently as it breaks down into some related compounds. This delayed reaction may enhance its value as a territorial marker, for it serves to keep the smell of a sprayed-urine mark alive longer.

Feces also play an important signaling role in cat territoriality. Studies of free-ranging cats have found that, contrary to popular belief, cats most definitely do not always cover their feces, or “scats.” They do so only about half the time, in fact.  Cats are much more likely to cover their scats when close to the core of their territory, however, especially the areas that include their habitual resting and sleeping spots. Outside the core area scats are frequently left. uncovered. The conclusion that scats serve a signaling function is reinforced by the fact that when in their usual sleeping or resting spots, cats usually move a few meters away before defecating, but outside their core range deposit their feces right on the trail where they are traveling. This same pattern of covering feces close to home but leaving them in the open when abroad has been observed in wildcats.  Covering scats close to home may serve a useful purpose in preventing the spread of parasites (cats notably do not like to eat in the same area in which they defecate) and also help the cats to avoid broadcasting the location of their home to potential predators.

The instincts of territoriality and marking territory are ever present in domestic cats. They may be modified through social circumstances, learning, or more direct manipulation such as drugs or surgery that alter hormone levels, but they are a basic part of the domestic cat’s heritage that, indeed, constitute some of the strongest instincts that exist in nature.