Maternal age effects on parenting and family outcomes are of increasing interest because of the demographic shift toward older maternal age at first birth. Maternal age is also of interest because of the greater use of assisted reproductive techniques (ART) to bypass age-related infertility in couples trying to conceive late in the reproductive life cycle of the woman. The aim of the present st...

BACKGROUND Son preference is predominant in developing countries especially South Asian countries and its effect is most visible when the fertility is on transition. Nepal is a country in South Asia where the fertility has declined and son is valued highly. This study examines the parent's gender preference for children and its effect on fertility and reproductive behaviors. METHODS Study was...

In this study, we investigated the age-dependent changes in reproductive efficiency of Kutum, Rutilus frisii  caught  from Shirood River,  the Southern Caspian Sea (Mazandaran Province, Iran). Age-dependent reproductive performance of brooders was assayed on two age and sex groups. Results revealed thatthere were no significant differences in sperm characteristics between age groups. All female...

In birds, the environmental variables and intrinsic characteristics of the nest have important fitness consequences through its influence on the selection of nesting sites. However, the extent to which these variables interact with variables that operate at the landscape scale, and whether there is a hierarchy among the different scales that influences nest-site selection, is unknown. This inte...