Sex determination in blue-fronted parrot (Amazona aestiva) using head and radiographic biometry

Abstract

Similar to most Psittaciformes, the blue-fronted parrot ( Amazona aestiva) lacks sexual dimorphism. In this way, sexing methods have been investigated to assist in the reproductive management and medical care of these birds. This study aimed to assess head and radiographic biometry for sex identification of blue-fronted parrots. Six head measurements and 23 radiographic measurements of 52 carcasses (24 males and 28 females) were taken. Males exhibited higher mean values than females for most of the measurements. For head biometry, the proposed discriminant equation containing rhinotheca length and head plus rhinotheca length allowed for correct sexing of 60% of males and 88% of females, while for radiographic biometry the discriminant equation containing head heigh and right alula length allowed the discrimination of 84.6% of males and 66.7% of females. This is the first study evaluating the use of radiographic biometry for sexing psittaciforms. Both biometric methods are suitable for sexing blue-fronted parrots when DNA sampling is not possible, since they are low-cost, provide immediate results, and are non-invasive techniques.