Geoscience Reference
In-Depth Information
Chapter 3
Animal Home Ranges and Territories and Home
Range Estimators
ROGER A. POWELL
Definition of Home Range
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Most animals are not nomadic but live in fairly confined areas where they
enact their day-to-day activities. Such areas are called home ranges.
Burt (1943:351) provided the verbal definition of a mammal's home range
that is the foundation of the general concept used today: “that area traversed by
the individual in its normal activities of food gathering, mating, and caring for
young. Occasional sallies outside the area, perhaps exploratory in nature,
should not be considered part of the home range.” This definition is clear con-
ceptually, but it is vague on points that are important to quantifying animals'
home ranges. Burt gave no guidance concerning how to quantify occasional sal-
lies or how to define the area from which the sallies are made. The vague word-
ing implicitly and correctly allows a home range to include areas used in diverse
ways for diverse behaviors. Members of two different species may use their
home ranges very differently with very different behaviors, but for both the
home ranges are recognizable as home ranges, not something different for each
species.
How does an animal view its home range? Obviously, with our present
knowledge we cannot know, but to be able to know would provide tremen-
dous insight into animals' lives. Aldo Leopold (1949:78) wrote, “The wild
things that live on my farm are reluctant to tell me, in so many words, how
much of my township is included within their daily or nightly beats. I am curi-
ous about this, for it gives me the ratio between the size of their universe and
mine, and it conveniently begs the much more important question, who is the
more thoroughly acquainted with the world in which he lives?” Leopold con-
