The impossibility of estimating a negative binomial clustering parameter from presence-absence data: a comment on He and Gaston.

An important problem is to infer the abundance of a species in an area from its presence or absence in the cells of a uniform grid. If the abundance is assumed to be distributed over cells according to a negative binomial model, a value of the clustering parameter k is needed to infer the abundance. It is shown that, despite a proposal in the literature, k cannot be estimated from presence-absence data but must be given from outside information.