When we think about menstruation, the first thing that usually comes to mind is humans.
However, did you know that there are some animals that also go through a similar process?
Menstruation is the regular shedding of the uterine lining in females when a fertilised egg does not implant. This process is common in humans but quite rare in the animal kingdom.
In most animals, the reproductive cycle does not involve menstruation. Instead, they reabsorb the uterine lining if pregnancy does not occur. However, a small number of animals, like humans, do shed this lining, leading to menstruation.
Before we discuss these animals that menstruate like humans, let’s review the meaning of menstruation.
A little insight into the meaning of menstruation
To understand menstruation, it’s helpful to know a bit about the reproductive system. Female mammals have a uterus, which is where babies develop.
Every month, in species that menstruate, the body prepares for pregnancy by thickening the lining of the uterus. This lining is rich in blood vessels and nutrients to support a growing baby.
If pregnancy doesn’t happen, the body no longer needs this thick lining. So, it sheds the lining through menstruation, which is what we see as a period. This cycle is controlled by hormones, which are chemicals in the body that tell it what to do.
With that in mind, let’s take a look at five animals that menstruate just like humans and get insight into the biology of how reproduction works across different species:
1. Chimpanzees
Just like humans, female chimpanzees have menstrual cycles. Their cycles are very similar to ours, lasting about 28 to 35 days.
During this time, if they do not become pregnant, they will shed their uterine lining and have a period. However, unlike humans, chimpanzees tend to have lighter periods with less blood loss.
2. Bonobos
Bonobos’ menstrual cycle is similar to both humans and chimpanzees. Bonobos have a period every 32 to 35 days. Like chimpanzees, their menstruation is not as heavy as in humans, but it’s a clear indication that they have a similar reproductive process.
3. Baboons
Baboons are another species of primates that menstruate. Female baboons have a menstrual cycle that ranges from 30 to 40 days. Their periods are often lighter than those of humans, but the process of shedding the uterine lining is quite similar. This is part of what makes baboons an interesting study in reproductive biology.
4. Elephants
Elephants are one of the few non-primate mammals that menstruate. Female elephants have a longer menstrual cycle, lasting about 14 to 16 weeks.
While their cycle is much longer than that of humans, the basic process is the same: if pregnancy doesn’t occur, they will shed the lining of their uterus.
5. Bats
Some species of bats also menstruate, though this is not common in all types of bats. The short-nosed fruit bat is one example. These bats have a menstrual cycle similar to primates, where they shed the uterine lining if they do not become pregnant. This is quite rare among mammals outside of primates.
