Blue-crowned manakins (Lepidothrix coronata) exhibit neotenic retention of subadult monomorphic plumage in sexually mature males. Definitively plumaged adult L. coronata are dichromatic, with males displaying a black body and blue crown while females retain green colouration characteristic of Pipridae species. Male neoteny and the reliance on soft tissue colouration to identify females make mature monomorphic L. coronata indistinguishable in the field, presenting research and management difficulties. The application of biometric measurements with discriminant function analysis (DFA) offers a practical methodology to sex L. coronata. Three DFA methods were compared using L. coronata of definitive plumage and known sex to determine the best modelling methodology for future applications. A linear discriminant analysis was performed using biometric measurements and combined with a principal component analyses. Quadratic discriminant analysis was performed using biometric measurements as a comparison to linear methodologies. Linear and quadratic discriminant analyses of biometric measurements produce a 92.86 and 91.2 per cent accuracy sexing definitively plumaged L. coronata, indicating applicability of statistical modelling as a potential solution for future field applications
