Multi-decadal studies, nondegenerate random variables, and a
half-century of studying acorn woodpeckers
Abstract
Long-term studies are subject to stochastic forces as well as
deterministic, ecological differences. We illustrate this by means of
Polya’s urn scheme and two examples based on our long-term study of the
behavioral ecology of the acorn woodpecker (Melanerpes formicivorus). In
both cases, the years during which the study was conducted had a large,
apparently stochastic influence on population dynamics. Despite such
variability, long-term studies offer several notable benefits, including
the opportunity to gain a more nuanced understanding of a particular
system and the ability to incorporate technological and theoretical
advances. Ultimately, it is with long-term data that we can hope to
disentangle and understand the stochastic and deterministic factors that
drive ecological systems.