WTPD Conservation Assessment - Endangered Species & Wetlands ...

to define, white-tailed prairie dog colonies are extremely difficult to characterize (Tileston and
Lechleitner 1966, Forrest et. al. 1985, Mariah Associates, Inc. 1986, 1987, 1988, Bio/West Inc.
1988, Patton 1989). In addition, densities of adults and yearlings within a colony are usually
significantly lower than those found in other prairie dog species (Lechleitner 1969, Clark 1977,
Hoogland 1979, 1981).
Sociality is less pronounced in the white-tailed prairie dog than in the black-tailed dog
and this may be due to their staggered activity periods and unpredictable environments. The
social system of the white-tailed prairie dog has been classified as a single-family female kin
cluster (Tileston and Lechleitner 1966, Michener 1983) comprised of several reproductive
females, occasionally one or two males of reproductive age and dependent young (Cooke 1993).
Females within a cluster are generally members of the same matriline (Cooke 1993). Within the
cluster, white-tailed prairie dogs spend little time in social maintenance and most of their active
time feeding (approximately 60%) (Tileston and Lechleitner 1966, Clark 1977,
Orabona-Cerovski 1991, Grant 1995). Conversely, black-tailed prairie dogs form polygenous
harems and spend much of their time in social integration (Michener 1983). Juvenile
white-tailed prairie dogs are more gregarious than adults for the first few weeks after emergence,
but by late summer their behavior resembles adults (Clark 1977). Overt defense of individual
white-tailed prairie dog cluster territories does not occur. However, during the breeding season
individual males monitor the reproductive condition of females and defend specific plots around
burrows allowing only receptive females to enter for copulation (Clark 1977, Cooke 1993).
Clark (1977) also found that females showed a weak defense around nest burrows just prior to
the emergence of young, but adult female-pup relations terminated soon after juveniles appeared
above ground (Tileston and Lechleitner 1966, Clark 1977).
Little work has been done examining home range sizes in different habitats and for
different sex and age classes with regard to white-tailed prairie dogs. In southeastern Wyoming
white-tailed prairie dogs home ranges ranged from 0.5 to 1.9 ha (1.2-4.7 ac) (Clark 1977) and in
north-central Colorado home range sizes ranged from 1,481.1 m 2 to 2,017.2 m 2
(1,771-2,412 yd 2 )(Cooke 1993). Home range sizes calculated for the Utah prairie dog were
found to range from 0.5 to 1.77 ha (1.2-4.4 ac) with the size of the home range inversely related
to density (Wright-Smith 1978 in McDonald 1992).
Emigration and immigration occur in early spring at the onset of the reproductive period
and again in late summer and early fall as young of the year disperse (Clark 1977). At study
sites near Laramie and Meeteetse, Wyoming, the percentage of immigrants into populations
ranged from 0% to 50% of the total animals captured with an average of 24% for all six colonies
examined (Menkens 1987). Anderson and Williams (1997) examined white-tailed prairie dog
colonies near Meeteetse during a plague epizootic. After plague was no longer present in the
area, colonies showed rapid increases and had high proportions of juvenile males. This led the
investigators to postulate that immigration led to the rapid increase in animal numbers. Menkens
(1987), Tileston and Lechleitner (1966), and Clark (1977) all have suggested that immigration
and emigration can contribute greatly in some years to white-tailed prairie dog population
dynamics.
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