Razão de sexo e considerações sobre o sistema de acasalamento em Nothura maculosa (Temminck, 1815) (Aves, Tinamidae)

Abstract

ln the presente study on the mating of Nothura maculosa (Temmlnck. 1815) the tertlary and quaternary sex ratios were jOlned toge- ther The sex ratio was 1: 1 or when deviated, favouring females When such deviations occur, they are probably due to quaternary sex ratio The Inverslon 01 sexual rôles could be responsible for the larger number of fe- males, slnce males are more exposed to mortality risks The matlng system ln the Tinamidae is simultaneous)loliginy for the male and sequentlal poliandry for the female , çmlen & Oring,. 1977 Such complexity ln the mating system results ln a greater share amorlg ali indi- v dua s in the reproductlon elfort in relation to poliginy The sexual inati- vlty of males Tor at least around 24 days after thé begining of incubation, allows new males to partlcipate in the reproductive eftort The assumptlon that some of the females wuld be excluded from the rep roductlve eflor! when sex ratio IS deviated in their iavour, probably can not be held as true Bump & Bump, 1969, reported that 95% of the eggs examined (114 eggs) , were fertile There are reasons to believe :hat neariy ali females will successfully copulate under these circunstances