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Among all the species, it is only the human female as well as the great apes that experience a true menstrual cycle. The other placental mammals experience the phenomenon called ‘estrus’ instead.
For most mammals, ‘estrus’ means a series of physiological changes which can be associated with courtship that helps ensure that mating occurs only during the estrus period of time. This is the brief stage where the female’s reproductive system allows eggs to be released and thus read more…