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r
e s e a r c h.. f o c u s :
Recovery of
a threatened species: The Utah Prairie Dog
Recovery
plans for most threatened or endangered species are based on relatively
simple population "viability analysis" that assumes the
greatest risk arises from small total  numbers
of individuals and random changes in births and deaths in the population.
This ignores that fact that most of these species live in fragmented,
patchy habitats containing very small, high-risk populations. Furthermore,
these patches may be unlikely to be colonized if they go "locally"
extinct. Population viability analysis that assumes the total "metapopulation"
is composed of small relatively isolated "local" populations
has been developed theoretically and tested on some insect species,
but has not been widely applied in the management of threatened
and endangered species.
Utah
prairie dogs are a small (0.5 - 1 kg) rodent restricted in distribution
to a series of spatially isolated valleys and plateaus in southwestern
Utah. Their e xtremely
slow rate of colonization of colonies that have gone "locally"
extinct through predation, poisoning, drought, and epizootics of
bubonic plague makes them an almost classic metapopulation. Adults
at all known Utah prairie dog locations have been counted since
the mid-1970's and these counts represent probably the bestspatially
explicit population data for any mammal.
Several
students and I have studied the effects of habitat and grazing on
Utah prairie dog body growth, reproduction, and survival in the
field and have analyzed patterns of fluctuation and local extinction
for the whole species' population. However, much work remains to
link these studies with those by other researchers studying effects
of plague to build a comprehensive metapopulation model for the
Utah prairie dog that can be used in planning its recovery.
Selected
Related Publications:
Ritchie,
M.E. 1999. Biodiversity and reduced extinction risks in spatially
isolated rodent populations. Ecology Letters 2: 11-16.
Ritchie,
M.E., Zablan, M., Bodenchuk, M., Bolander, R., Bonebrake, R.,
Grandison, K., McDonald, K. 1997. Utah prairie dog interim conservation
strategy. U.S. Fish and Wildlife Service, Salt Lake City,
Utah, 25 pp.
For
more details about my other research and related publications, please
select from the following:
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