Evaluation of animal deformity occurrence in natural populations (an example of amphibians)

Abstract

A new approach is proposed to evaluate the occurrence of amphibian deformities in natural populations. The background and mass occurrence is suggested to separate by convenient level of 5 percent of malformed animals (sample size ?100 specimens is recommended). The system containing three groups of quantitative parameters are considered: a) frequency of malformed animals, Pas; b) frequency of abnormalities (A), including partial (Ap) and relative frequency (Ar); and c) spectrum of abnormalities (Sa), including individual (Sai) and population (Sap) deformity diversity in natural populations and some other parameters (μ and h of Zhivotovsky 1980). Some measures of combined occurrence of abnormalities and abnormality overlap are also analysed (indices of Morisita, and of Czekanovsky–Sorensen). Some aspects of field work are discussed (sampling, age groups, abnormality classification as well as syndrome expression of malformations).