The reliability of morphometric discriminant functions to determine the sex of Chilean Flamingos (Phoenicopterus chilensis)

MONTALTI, D.; GRAÑA GRILLI, M.; MARAGLIANO, R.; CASSINI, G.

CURRENT ZOOLOGY

Current Zoology

Lugar: Beijing; Año: 2012 vol. 58 p. 851 - 855

1674-5507

Monomorphic birds cannot be sexed visually, and hence discriminant functions on the basis of external morphological variations are frequently used. Our objective was to evaluate the reliability of sex classification functions created from structural measurements of Chilean Flamingo (Phoenicopterus chilensis) museum skins for the gender assignment of live birds. Five measurements were used to develop four discriminant functions: culmen, bill height and width, tarsus length and middle toe claw. Then the functions were tested on a sample of live flamingos from a zoo. The best classification for museum flamingos was given by a function using tarsus length, bill width and middle toe claw (97%). However, this function did not give the best classification for the zoo flamingos (81%) which had the best sex assignement by a function including the measurements of tarsus, culmen and bill height and width (85%). This shows that a function giving good results in the sample from which it was originated may not be as good when applied to another group of animals. It emphasizes the need for assessing the accuracy of a function by testing it with other methods to ensure its suitability when being applied.