Fluctuación anual del peso corporal, tamaño de gónadas y muda del pirincho (Guira guira)

DARRIEU C.A.; CAMPERI A.R.; MONTALTI D.

Tafí del Valle, Tucumán

Congreso; XIII REUNIÓN ARGENTINA DE ORNITOLOGÍA; 2009

Aves Argentinas

The relationships between body mass, gonadal size and postnuptial molt of Guira Cuckoo Guira guira were determined based on 92 specimens (53 males and 39 females) collected at Magdalena district (Buenos Aires province) during an annual period. By taking the yearly average, no significant differences were found between body mass of males and females. For both sexes were determined two periods of variation in the size of the gonads: one of increase activity (September-January) and the other of sexual inactivity (April-August). Males showed an earlier gonadal development than females. The first egg laying began in October. In mid-December began a decline in the size of the gonads in relation to the onset of postnuptial molt, which peaked in March. The molt is asymmetric, 85,8% of the studied specimens were in molt. The process was extended to May inclusive.