Properties and interpretation of the Skellam model -- a discrete-time
contest competition population model
Abstract
The Skellam model describes discrete-time population dynamics of a
single species assuming uniform (i.e., random or Poissonian) individual
distribution and intraspecific contest competition. Apart from studies
on individual-based models derived from first principles, it has rarely
been applied to ecological research. However, in specific situations, it
may be more appropriate than, for instance, the frequently used Ricker
model. This is derived from assuming scramble competition among
individuals. In this paper, we offer insight into the first principles
underlying the Skellam model. In addition, we provide an alternative
parameterization of the model in terms of two commonly used parameters:
intrinsic rate of population increase and carrying capacity. In light of
these findings, the Skellam model may be a useful alternative for a
range of purposes where it has previously been overlooked, e.g., in
fitting population models to time series data.