  Advances in field techniques have lead to an increase in spatially-referenced
capture-recapture data to estimate a species' population size as well as other
demographic parameters and patterns of space usage. Statistical models for
these data have assumed that the number of individuals in the population and
their spatial locations follow a homogeneous Poisson point process model, which
implies that the individuals are uniformly and independently distributed over
the spatial domain of interest. In many applications there is reason to
question independence, for example when species display territorial behavior.
In this paper, we propose a new statistical model which allows for dependence
between locations to account for avoidance or territorial behavior. We show via
a simulation study that accounting for this can improve population size
estimates. The method is illustrated using a case study of small mammal
trapping data to estimate avoidance and population density of adult female
field voles (Microtus agrestis) in northern England.
