What animals have periods?

A period is the shedding of the inner lining of the womb visible through the vaginal tract. The shedding is primarily made up of blood and can contain endometrium tissues and unfertilized eggs or defected eggs. 

Mensuration is mainly specific to higher oder mammals, placental mammals to be specific, those who have specially built organs called placentals for nourishing their young ones during gestation. There are however, a few observed cases in other mammals different from primates.

Most other females of the mammalian clade undergo an estrous cycle rather a menstrual cycle characterized by the absorption of their inner linings rather then it’s expulsion.

The section below enumerates the current members of the animal kingdom that have been observed to undergo a menstrual cycle.

What animals have periods?

Most mammals that menstruate belong to the Ape family and the new world monkey family. The ape family is divided into two basic groups by the way, they include the Great Apes and the lesser apes.

1) Female human

Female period

Higher order primate belonging to the Great Ape family.

It’s shouldn’t be a surprise that the number  one take on the list are female homo sapiens a.k.a female humans. They grow the most thickest lining of all menstruating animals and bleed the most.

The average female human typically starts menstruating around the age of 12. The general span is usually between 8 on the lower menstrual spectrum and 16 on the higher end of the spectrum.

Periods usually occur about once every 4 to 5 weeks, (28 to 41 days), lasts for about 6 to 7 days and the amount of blood shed out can vary greatly between individuals from mild, moderate to very severe in some cases. Most females typically loose no more than one tablespoon during their period.

Menstruation in female humans can be painful (induces cramp), and sometimes bring about emotional and physical syndrome, (premenstrual syndrome) the likes of acne, moodiness, anxiety, sadness, bloating and acne. These usually subside after a few days.

2) Other Great Apes

Gorilla period

Other members of the Great Ape family, aside humans also menstruate too, but their menstrual cycle is a bit less pronounced.

The occurrence and duration of the cycle varies subtly across different species of the group. Menstruation typically starts after maturity, which happens around the age between 8 to 10 years for individuals in the wild and 6 to 7 years for those in captivity.

The quick maturity in the captive apes is as a result of the fact that they receive more nutritious food than their wild counterparts, which enables them to mature faster.

Here are some of the members and their mestrual cycles.

  • Orangutans: Menstrual cycle last for about 29 days and the duration of their period is between 4 to 5 days.
  • Gorillas: Menstrual cycle last for about 30 days and the duration of their period is between 2 to 3 days. Bleeding is easily detectable.
  • Bonobos: Menstrual cycle last for about 32 to 35 days and the duration of their period is between 17 to 36 days.
  • Chimpanzees: Menstrual cycle last for about 37 days and the duration of their period is around 14 days. Chimpanzees bleed less copiously and thus blood is only visible upon closer examination.

3) Lesser Apes

Higher order primate belonging to the Great Ape family.

Gibbon period

The other group of the Apes, the lesser apes, also known as gibbons, belonging to the family Hylobatidae have also been observed to menstruate. These species typically resemble new world monkeys (regular monkeys) but the characteristic that set them apart and the ones that justifies their ‘Ape-hoodness’ is the lack of tails.

Lesser Apes typically mature between the age of 4 to 5 years and menstruation can start any moment from that period.

Menstrual cycle in gibbons can last for upto 25 days and the duration is usually around 3 days or so. Mestrual bleeding in gibbons unlike some species of great apes, is easily detectable from their underside.

Lesser Ape species include: siamang, the white-handed or lar gibbon and the hoolock gibbons.

4) Old world monkeys

Baboon period

Monkeys living in Asia and africa

Higher order primate belonging to the Old world monkey family, sisters to the Great Ape family.

Old world monkeys which include baboons and macaques also have been confirmed to menstruate.

These group are phylogenetically more closely related to the apes than new world monkeys and are thought to have diverged from them about 55 million years ago.

Like apes, menstruation in old world monkeys begin at different ages with the cycle and duration varying somewhat between species.

Generally, menstrual cycle in old world monkeys can last between 14 to 35 days and duration can last between 2 to 3 days. Here are some of the species and their menstrual data.

  • Baboons: cycles range from 30 – 35 days
  • Patas monkey: cycles range from 24 – 27 days,
  • Vervet monkeys: cycles range from 30 – 31 days,
  • Mangabys: cycle range from 30 – 34 days
  • Macaques: cycle range about a month

5) Spiny mouse

Spiny mouse period

The spiny mouse is one of the few menstruating mammals that do not belong to the higher order primates. It’s a rodent similar to mice endowed with stiff guard hairs similar to the spines of a hedgehog; hence it’s name.

The spiny mouse menstrual cycle ranges between 6 to 10 days with the menstrual period lasting for about three days.

6) Bats

Bat period

No all species of bats have been observed to menstruate. So far, menstrual cycle has been observed in a total of four bat species which all belong to the phyllostomid family. The bats include:

  • Seba’s short-tailed bat (Carollia perspicillata)
  • Common vampire bat (Desmondus rotundus)
  • Black mastiff bat (Molossus rufus)
  • Pallas’s long-tounged bat (Glossophaga soricina)

Menstrual cycle in bats can range from 21 to 27 day and periods can last for about 5 days or so.

7) Elephant shrew

Elephant shrew period

Members of the Macroscelides Family. 

Elephant shrew, a species that is strictly native to Africa is also part of the placental mammals with overwhelming evidence from research that indicates menstruation in them. 

Menstruation cycle and period in elephant shrew lasts for nearly the same period as observed in humans.

More interesting articles:


Ronald. (2008, September 11). Primate Menstrual Cycle [Blog Post]. Retrieved from http://pin.primate.wisc.edu/aboutp/anat/menstrual.html

Cite this Article (APA Format)

Bunu. M. (2020, May 25). What animals have periods?. Retrieved from http://emborawild.com/animals-that-menstruate/

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