Behavior

Watching wolves jostle for dominance or red foxes in courtship is to witness a complex, fast, and subtle dance, incorporating not just movement but sounds, smells, and touch.

A crab-eating fox (Cerdocyon thous) eating a crab, as its common name suggests. (Illustration by Wendy Baker)

The outcomes of such interactions will determine who mates with whom and which animals will disperse, i.e., whose genes will be represented in future generations. In many cases the information acquired during play and other non-hostile interactions will eliminate the need for more openly hostile confrontations later. An individual can assess where he or she stands without having to fight.

The complex interactions are built up from simpler units or elements (e.g., a growl, or a wagging tail). These elements combine to form gestures and gestures between individuals form interactions. Interactions between pairs (or larger groups) form relationships. The pattern of relationships in a pack or group, in turn, determines the social system. Social behavior is a complex hierarchy that is hard to study. Luckily at the lowest level, the elements of social behavior are quite uniform among all the canid species (and recognizable by the owners of domestic dogs). As an example, among facial expressions all canids can snarl aggressively (upper lips lifted vertically) and "grin" submissively (lips retracted backwards). All species may show a defensive gape with the mouth held wide open as a shield. However, it occurs much more commonly in fox-sized species. The position and movement of the tail is similar in most canids and there is a graded signal from the tail tucked between the legs in defensive submission to tail held high in assertive dominance. In a study on jackals a scientist noted the exact element of behavior from twelve parts of the body (e.g., ears, muzzle, head turning, tail, hackles) as they were combined to produce gestures. The exact gesture virtually never repeated itself, reflecting the complexity of the interactions.

Vocalizations are integral in many close interactions and loud vocalizations, e.g., howls, can also carry to communicate with animals far away. One problem with studying vocalizations in canids is that we know they can hear at higher frequencies that we can. Humans probably hear only a part of the signal with their ears. (Ultrasound analysis allows us to "see" these noises but few have been analyzed.) As with the other elements of behavior, many of the squeaks, grunts and growls of close interactions seem similar across the canids (modified by the size of the voice box so that small species produce a higher pitched version of a noise). The growl is one of the sounds made by all canids and indicates threat. In an intense form it grades into a bark but barks are not commonly heard. However, this warning vocalization must have been found useful by the early domesticators of the wolf and is now triggered by almost any arousing or threatening stimulus in domestic dogs. The most evocative and loudest of canid vocalizations are designed for long distance propagation. Wolves, coyotes, and jackals all have howls (and interesting variants occur in African wild dogs and dholes). A pure-tone howl produced by a lone individual wavering around a single frequency acts to bring the pack together. The much more complex group howl which includes several individuals, some howling, some barking, and some growling is a territorial signal asserting rights to the land. It has been suggested that the complexity of the group howl with certain wolves changing pitch may deceive listeners into believing that the pack has extra members. It was believed for years that African wild dogs did not howl and packs are so spread out that a vocal threat like a group howl would have nobody to hear it. Recently group howls have been heard on the rare occasions when two packs do bump into one another. They have the same rich texture as group howls by wolves and seem to act as a threat. The dhole uses a pulsed whistle to locate pack members and a group howl between packs.

A golden, or common, jackal (Canis aureus) with a mouse. (Photo by Rudi van Aarde. Reproduced by permission.)
Silverback jackals (Canis mesomelas) "body slam" play in Kenya. (Photo by K & K Ammann. Bruce Coleman, Inc. Reproduced by permission.)

Olfactory communication is almost completely outside human perception but probably plays a major role in the life of a canid. Glands on the feet, skin, lips and anus are modified for secretion and in some species many of the glands associated with the hairs on the dorsal surface of the tail produce odor. Anal gland secretions rub off on feces and a variable mixture of bacteria in the anal sacs ensures that individuals have a unique odor. Sex and reproductive status, at least, are detectable in the urine. Urine marking by cocking a leg is seen in all adult species. Unlike domestic dogs where only males cock a leg, in wild canids the dominant male and dominant female both usually display the behavior. Marks are usually distributed around the edge of the territory and typically both members of the pair mark consecutively. The bush dog female has a peculiar marking behavior in which it backs up against a tree or post and deposits urine about two feet above the ground, presumably to increase its dissemination in the forest habitat. Bush dog males exhibit a typical leg cock.

Many of the most complex interactions occur in the context of dominance and submission. Whether in pairs or larger groups, stronger individuals have the power to monopolize important resources. The degree to which they assert their status depends on the extent to which they depend on other members of the group. In packs of African wild dogs, the species with the greatest social interdependency, dominance hierarchies are established in both males and female but their expression is muted. Expressions of subordination, or the willingness to accept the position or status of the dominants, are usually demonstrated effusively in all species. Subordination comes in two forms passive and active. In passive submission the inferior dog rolls on it back in front of the dominant. The gestures of active submission (or greeting) are derived from the begging of pups and subordinates mob a dominant thrusting their muzzles into his or her face. In wolves a dominant animal may either regurgitate or drop a bone or other food item in response to these greetings. Dominant individuals breed and the dominant or alpha male will prevent other males from mating while the alpha female will keep other females away. Relationships within monogamous pairs are usually fairly egalitarian with time spent resting and traveling, grooming and greeting together. Males are typically 10-15% larger than their mates which may explain why the majority of active submission seems to be directed by the female to the male.

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