HOME RANGE, TERRITORY, TIME ELEMENTS AND
PREDATOR - PREY RELATIONSHIPS

Animals in captivity show all the behavior of their wild conspecifics, as well as behavior stemming from their captive situation. The zookeeper must be aware that all or a part of the exhibit may be a defended territory. A good grasp of some concepts may create a safer workplace.

Animals don't live completely free in a wild state because their living space is confined by boundaries that are often invisible to the casual observer. The size of the area used is determined often by individual and species needs and environmental limitation. Distribution or range is the geographic distribution of the species. Within this range only areas of suitable habitat are occupied. In the case of migratory species distant areas connected by rather narrow migratory corridors may comprise the range. Habitat is the area within the range that contains the environmental factors and conditions needed to support the species. You could think of habitat as the animal's address. Ecological niche describes the role of the animal within its community. It considers what the animal does in relation to the food chain, plant and animal associations and energy flow. The niche might be compared to an occupation.

To put this in perspective, the geographical distribution or range of the mountain goat, Oreamnos americanus, is the Rocky Mountain cordillera from the North Slope of Alaska to Yellowstone National Park plus the West Coast Cascade Mountains. Its habitat is the steep craggy areas from near sea level to above 4000 m, generally wintering at very high altitudes. Its ecological niche is that of a large herbivore living in small herds, preyed on by golden eagles, mountain lions and grizzly bears. Home Range is the living area normally occupied and inhabited by an animal. It may belong to a single individual, a mated pair or a social unit, a cohesive group with a single dominant individual. Within the home range there is often a defended area which is identified as a territory. Typical behavior is usually associated with establishing and defending or protecting the animal's territory. This behavior and reproductive behavior associated with the territory is unique for each species, and allows several different animal species to live in the same space without rivalry, using different niches within the habitat. Some species maintain a permanent territory while others only establish one during the breeding season. It seems uncommon for migratory birds to establish winter territories.

Certain seabirds, seals and rodents live in large densely populated colonies within which territories as small as a nest or breeding site are defended. Territory size is often related to the body size of the animal and its feeding habits, with larger forms usually having larger territories than smaller species and carnivorous forms defending larger areas than herbivores

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Not every part of the home range is used evenly. Often trails lead from one activity area to another. Preferred routes exist on the ground, through treetops in water or air. Often parts of the home range may be used for loafing, feeding, sleeping, drinking, bathing or defecating.

Animals are reluctant to change their patterns of movement, and familiar sites provide security. The "home" aspect is as important to many other species as it is to the human species as it provides a safety zone within the home range. Animals that have escaped confinement in the zoo will often return to their enclosure (home range) if given the opportunity.

The territory is important to those animals that possess one and it is most often vigorously defended against conspecifics and to a lesser extent or sometimes not at all against other species. The more similar species are, the more likely it is for territorial disputes to occur. Territoriality is recognized as a component of "personal space". In group species this is the distance inside of which the intrusion of a fellow member of the species creates stress where that intruder is a mate or immature. In humans this distance is about an arm's length in western societies but is somewhat less in Mediterranean countries. Perhaps you have felt discomfort when an Italian or Greek talked to you "in your face". Another component is what is recognized as critical distance. Encroachment of an intruder within this distance may elicit an attack. Flight distance is recognized in many prey species which, while they may defend a territory against conspecifics, flee when a perceived potential predator gets within this distance. Flight distance can be modified by habituation so zoo animals that would ordinarily flee from humans in the wild tolerate the close approach of visitors within the zoo.

A territory may be delineated so other members of the species can recognize it in several ways depending upon the species. Optical, acoustic or olfactory cues or a combination of these are often used. Optical or visual demarcation may involve using the whole body or even parts of it. It has been called static-optical when the result arises from the presence or appearance of the animals' body in the territory as in the giraffe, and dynamic-optical when the animal uses a special signaling device in a stereotypical movement (the waving of the fiddler crabs claw). Form and color are often important.

Acoustic demarcation includes the singing of birds, the calling of amphibians, the bellowing of alligators, the hooting of some primates and the buzzing of some insects. All serve to advertise the presence of a territory.

Olfactory demarcation is very common among mammals with a well-developed sense of smell. Urine, feces and products of special scent glands are used alone or in conjunction to mark out the territory. Generally male scent glands are more elaborate than those of the females.

Just like people other animals are creatures of habit, awakening, moving within their home range and feeding at routine times and places. These movement patterns are often clearly visible in zoos. Llamas, rhinos, muntjac and stallions routinely use special places for defecation. Even in small exhibits animals establish specific routes for travel within the exhibit. Part of the exhibit may be devoted to eating or sleeping.

Grizzly bears are abundant in Denali National Park and
are often seen in feeding in groups on berries.