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complex model and distinguishing stochastic variation from deterministic
dynamics.
Wildlife biologists in particular seem to suffer from what I call the tech-
niques syndrome: They are preoccupied with resolving how to compile reliable
field data, often at the expense of understanding what one might do with the
data once obtained. This became particularly apparent to me during my
tenure as editor-in-chief of the
Journal of Wildlife Management,
where I was
surprised to discover that fully 40 percent of the manuscripts submitted to the
journal in 1995-1996 were on techniques rather than wildlife management.
Such a preoccupation with techniques has been symptomatic of wildlife cur-
ricula in the United States. For example, the capstone course in my under-
graduate training at Iowa State University in 1972 was a course in wildlife
techniques; principles were presumed to have emerged from lower-level
courses in animal and plant ecology.
In this context, one might find it curious that a chapter on predator-prey
modeling would appear in a topic on techniques. Modeling is indeed viewed
by some as a technique. I prefer to consider modeling as a way of thinking and
structuring ideas rather than a technique. We sometimes use modeling as a
technique; for example, we might use predator-prey modeling to predict the
nature of population fluctuations and to forecast future population sizes. In this
vein, predator-prey modeling can be used as a technique for assisting managers
with decision making. Modeling also can be used to test our assumptions about
predator-prey interactions and to guide the collection of data. Modeling pro-
vides the impetus for what Galileo called the “cimento” (experiment). To my
mind, most fundamentally, predator-prey modeling is used to improve our
understanding of system dynamics emerging from trophic-level interactions.
Modeling Approaches for Predator-Prey Systems
j
Approaches and objectives for modeling predator-prey interactions can vary a
great deal. I classify predator-prey models into three classes: noninteractive
models in which one or the other of a predator-prey interaction is assumed to
be constant, true predator-prey models in which two trophic levels interact,
and statistical models for characterizing the dynamics of populations that may
be driven by a predator-prey interaction. Predator-prey interactions are simi-
lar to plant-herbivore interactions, and indeed, the same models have been
used to characterize plant-herbivore interactions (Caughley 1976) as have
been used to characterize predator-prey interactions (Edelstein-Keshet 1988).
