Age related changes in external anatomy, and song-based gender identification in local guinea fowls (Numida meleagris)

Abstract

There is hardly any research data on the external anatomy of guinea fowls. Three hundred and sixty local guinea fowls, involving 180 each of males and females were studied, and documented the developmental variations in the external anatomy of these birds from hatching until adulthood. The study also explored the call-based approach as an alternative sexing method in these birds. Externally, all the birds changed from brownish black-stripped down feathers at hatching to white regular spotted or pearl feathers by 8th week of age (WOA). Both sexes began to emit their respective calls from 8 WOA, while moulting of the neck feathers started between the 4th and 6th WOA and completed between 12 and 16 WOA. All external biometric traits increased significantly (P<0.0001) from first WOA and plateaued at different ages. Wing span and tail length plateaued at 16 WOA, abdominal and pelvic inlet widths stabilized at 20 WOA, head-bill length, width, neck and body lengths stabilized from 24 WOA, cere and wattle lengths, as well as body weight continued to increase until the end of the study. Significant development in most external biometric traits was accomplished from 24 WOA, while the type of call emitted could be used to discriminate between the two sexes at 100% level of accuracy from 8 WOA.