Geoscience Reference
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the availability of food across its home range and on the locations of the other
patches of food.
In addition, Gautestad and Mysterud (1993, 1995) showed that if animals
move in a manner described by a multiscale random walk that incorporates the
multiscale, fractal nature of animal movements, then the estimated home
range area should increase infinitely in proportion with the square root of the
number of location estimates used to estimate the area of the home range using
a minimum convex polygon. Indeed, the home ranges of several species, quan-
tified using minimum convex polygons, do appear to increase in area as pre-
dicted (Gautestad and Mysterud 1993, 1995; Gautestad et al. 1998). The pre-
dicted relationship between home range area (
A
MCP
, for minimum convex
polygons) and the number of locations (
n
) is
A
MCP
=
C
·
Q
(
n
) ·
n
1/2
(3.1)
where
C
is the constant of proportionality, or the scaling factor, and
Q
(
n
) is a
function that adjusts the relationship for underestimates of
A
MCP
because of
small sample size. Curve fitting indicates that
Q
(
n
) = exp(6/
n
0.7
)
for
n
5. When not calculating home range area from minimum convex poly-
gons,
Q
(
n
) should not be used.
Gautestad and Mysterud (1993) interpret
C
to be a measure of how an ani-
mal perceives the grain of its environment. When a grid is superimposed over
a plot of an animal's locations,
C
can be calculated for each cell and 1/
C
is a
descriptor of the intensity of use for each cell (Gautestad 1998).
1/
C
can be calculated in two ways. Superimpose a grid on a map of a study
area such that no cells have fewer than five locations for a target animal (cells
with fewer than five locations might alternatively be ignored). Calculate the
area of the minimum convex polygon formed by all locations within each cell
and use that for
A
MCP
in equation 3.1. Calculate 1/
C
as
³
1/
C
= [
Q
(
n
) ·
n
1/2
]/
A
MCP
Alternatively, 1/
C
can be calculated in a manner that uses different scales.
Superimpose a grid on a map of a study area with cell size such that one cell
contains all the locations of given animal. The area of the single can be con-
