Work out mark recapture population instantly with clear inputs, formula shown and shareable results.
Applies the Lincoln-Petersen ratio and the less biased Chapman correction to estimate population size from mark and recapture counts.
Mark-recapture
Lincoln-Petersen: N = M x C / R. Chapman: N = ((M+1)(C+1) / (R+1)) - 1, which is less biased at small sample sizes
A closed population, equal catchability and marks that neither fall off nor change behaviour.
Lincoln-Petersen is biased upward and undefined when no marked animals are recaptured; Chapman remains finite.