COMDYN: software to study the dynamics of animal communities using a capture-recapture approach

COMDYN is a set of programs developed for estimation of parameters associat ed with community dynamics using count data from two locations or time peri ods. It is Internet-based, allowing remote users either to input their own data, or to use data from the North American Breeding Bird Survey for analy sis. COMDYN allows probability of detection to vary among species and among locations and time periods. The basic estimator for species richness under lying all estimators is the jackknife estimator proposed by Burnham and Ove rton. Estimators ave presented for quantities associated with temporal chan ge in species richness, including rate of change in species richness over t ime, local extinction probability, local species turnover and number of loc al colonizing species. Estimators are also presented for quantities associa ted with spatial variation in species richness, including relative richness at two locations and proportion of species present in one location that ar e also present at a second location. Application of the estimators to speci es richness estimation has been previously described and justified. The pot ential applications of these programs are discussed.