Few mammals actually get periods every month, or even at all, but why? Understanding what menstruation really is and why it happens could help ease symptoms & treat conditions that stem from the ...

Human animals have a simple, direct system: copulation and sperm delivery may lead to fertilization of an egg, if the timing is right. Once a sperm joins an egg, the resulting zygote gets implanted on ...

A new article in Ecological and Evolutionary Physiology examines how the immune system and reproduction interact in female mammals, especially during pregnancy, from mating to birth. Lauren E.

Energy intake is a critical determinant of reproductive performance in small mammals, particularly during energetically demanding periods such as lactation. Recent investigations have revealed that ...

Around age 50, women abruptly become infertile in a striking and puzzling permanent “change of life”—menopause. Although age at menopause ranges from 42 to 56 between women, an average near 50 is ...

Wild animals that have acquired adaptations to maximize their reproductive output in some of the world's most extreme conditions may provide answers to some of the most pressing problems in the field ...

Why do lifespans vary across different species? A female elephant can live up to 80 years, but usually only has a few calves during her lifetime. A mouse, on the other hand, lives for a few years at ...

A quiet revolution in recognizing menopause in other mammals was sparked by a 1990 whaling report indicating the presence of post-reproductive females among resident killer whales in coastal waters ...