effects of mating sex ratios on production performance in indian peafowl were investigated at punjabwildlife research institute, gatwala faisalabad. research was conducted from may through august 2007 toexplore the most productive mating sex ratio. the sex ratios have a significant effect on egg production.maximum mean eggs (1.63) were produced by the sex ratio 1:2 while maximum egg fertility (...

Effects of mating sex ratios on production performance in Indian peafowl were investigated at PunjabWildlife Research Institute, Gatwala Faisalabad. Research was conducted from May through August 2007 toexplore the most productive mating sex ratio. The sex ratios have a significant effect on egg production.Maximum mean eggs (1.63) were produced by the sex ratio 1:2 while maximum egg fertility (...

An experiment was conducted to assess the optimum nutrient requirement and ideal mating ratios for Alabio ducks for production of fertile eggs and hatchability under rural feeding management. A total of 135 forty weeks old females and 27 males were used in the study. They were fed on low (17.5%), medium (19.5%) and high (21.5%) crude protein (CP) in diets containing approximately 3050 kcal of m...

Populations of Acer species often contain more than three sex phenotypes with complex sexual polymorphism including duodichogamy, protandry and protogyny. We identified the mechanisms that maintain sexual polymorphism in Acer pictum subsp. mono, a temperate tree from northern China, by investigating maternal mating patterns and male reproductive success. We used paternity analyses to estimate r...

The reversal of conventional sex roles was enigmatic to Darwin, who suggested that it may evolve when sex ratios are female biased [1]. Here we present direct evidence confirming Darwin's hypothesis. We investigated mating system evolution in a sex-role-reversed beetle (Megabruchidius dorsalis) using experimental evolution under manipulated sex ratios and food regimes. In female-biased populati...

Two-sex populations are usually studied through frequency-dependent models that describe how sex ratio affects mating, recruitment and population growth. However, in two-sex populations, mating and recruitment should also be affected by density and by its interactions with the sex ratio. Density may have positive effects on mating (Allee effects) but negative effects on other demographic proces...

Two-sex populations are usually studied through frequency-dependent models that describe how sex ratio affects mating, recruitment and population growth. However, in two-sex populations, mating and recruitment should also be affected by density and by its interactions with the sex ratio. Density may have positive effects on mating (Allee effects) but negative effects on other demographic proces...

Although multiple mating most likely increases mortality risk for social insect queens and lowers the kin benefits for nonreproductive workers, a significant proportion of hymenopteran queens mate with several males. It has been suggested that queens may mate multiply as a means to manipulate sex ratios to their advantage. Multiple paternity reduces the extreme relatedness value of females for ...

The sex ratio behavior of parasitoid wasps in the genus Melittobia is scandalous. In contrast to the prediction of Hamilton's local mate competition theory, and the behavior of numerous other species, their extremely female-biased sex ratios (1-5% males) change little in response to the number of females that lay eggs on a patch. We examined the mating structure and fitness consequences of adju...

Background: To curtail competition with their own sperm, males of several spider and insect species mutilate their genitals or sacrifice themselves entirely using their genital parts or their whole dead bodies as mating plugs. The orb-web spider, Argiope aurantia, is a species characterized by both male self-sacrifice and extreme female-biased sexual size dimorphism. Plugs may reduce female mat...