Resumo
In the presente study on the mating of Nothura maculosa (Temminck, 1815) the tertiary and quaternary sex ratios were joined together The sex ratio was 1:1 or when deviated, favouring females When such deviations occur, they are probably due to quaternary sex ratio The inversion of sexual rôles could be responsible for the larger number of females, since males are more exposed to mortality risks The mating system in the Tinamidae is simultaneous poliginy for the male and sequential poliandry for the female, Emlen & Oring, 1977 Such complexity in the mating system results in a greater share among all individuals in the reproduction effort in relation to poliginy The sexual inativity of males for at least around 24 days after the begining of incubation, allows new males to participate in the reproductive effort The assumption that some of the females wuld be excluded from the reproductive effort when sex ratio is deviated in their favour, 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 that neariy all females will successfully copulate under these circunstances
Razão de sexo e considerações sobre o sistema de acasalamento em Nothura maculosa (Temminck, 1815) (Aves, Tinamidae)
João Aldair Menegheti
Museu de Ciências naturais da Fundação Zoobotânica do Rio Grande do Sul, Porto Alegre, RS
ABSTRACT
In the presente study on the mating of Nothura maculosa (Temminck, 1815) the tertiary and quaternary sex ratios were joined together The sex ratio was 1:1 or when deviated, favouring females When such deviations occur, they are probably due to quaternary sex ratio The inversion of sexual rôles could be responsible for the larger number of females, since males are more exposed to mortality risks
The mating system in the Tinamidae is simultaneous poliginy for the male and sequential poliandry for the female, Emlen & Oring, 1977 Such complexity in the mating system results in a greater share among all individuals in the reproduction effort in relation to poliginy The sexual inativity of males for at least around 24 days after the begining of incubation, allows new males to participate in the reproductive effort
The assumption that some of the females wuld be excluded from the reproductive effort when sex ratio is deviated in their favour, 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 that neariy all females will successfully copulate under these circunstances
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AGRADECIMENTOS
O autor agradece o apoio e estímulo da Dra Miriam Becker; aos Diretores da Fundação Zoobotânica e Museu de Ciências Naturais, Médico-Veterinário Heraclides Santa Helena e Biólogo Gilberto Carvalho Ferraz pelo incentivo e suporte administrativo; à colega Maria Inês Burger Marques pela crítica ao manuscrito e participação no trabalho de campo. Ainda, pela revisão do manuscrito, às colegas Marta Fábian e Tania Arigony.
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Datas de Publicação
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Publicação nesta coleção
17 Ago 2009 -
Data do Fascículo
1988
