Periods are a strange phenomenon. We don’t know why humans have them, or, to look at it another way, why most other animals don’t. Scientists say only 1.5 percent of mammal species have periods, and most of those are primates like us. The ranks of the menstrually afflicted grew a little bit recently, as researchers learned that female spiny mice have periods, too. They shared their findings on the bioRxiv preprint server.
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Why did it take scientists so long to notice that these curious creatures were part of the period posse? “The answer, as with many discoveries in science, is that no one really looked,” said Hayley Dickinson, a reproductive physiologist and long-time spiny rat researcher at the University of Monash. “Everyone knew that rodents didn’t menstruate.”
For the full story, see:
Nowogrodzki, Anna. “First Rodent Found with a Humanlike Menstrual Cycle.” Nature (Fri., June 10, 2016).
(Note: ellipsis added.)
The preprint of the research mentioned above is:
Bellofiore, Nadia, Stacey J. Ellery, Jared Mamrot, David W. Walker, Peter Temple-Smith, and Hayley Dickinson. “First Evidence of a Menstruating Rodent: The Spiny Mouse (Acomys Cahirinus).” bioRxiv (June 3, 2016).