How Many Babies Hamsters Can Have In A Year

Hamsters, like most rodents, are prolific breeders. But just how prolific are they? You may know how many hamster pups are typically produced in one litter, but that is only part of the story. There are a number of factors involved when considering the reproductive capabilities of a hamster. You may be surprised at just how many litters, and therefore pups, a female hamster is capable of producing each year.

How many babies can a hamster have in one year? With the average hamster litter containing 6-8 pups, and a female capable of producing 18 litters per year, the average hamster can produce 144 hamster pups each year. This is not considering the above-average producers who can carry and birth up to 20 pups in a single litter.

Multiple factors are at play when considering how productive hamsters are at breeding. Read on to learn more about hamster gestation, and what it is that allows them to produce so many pups in so little time. 

How Is It Possible For Hamsters To Have So Many Babies?

Having the capability of producing well over one hundred pups in a single year may sound astounding (and it is), but there are a few different factors that make this possible.

This includes the short estrus cycle, the quick return to heat after pregnancy, the short gestation, the male hamster’s reproductive drive, and of course, litter size. Let’s take a look at each of these factors. 

Female hamsters have a short estrus cycle

Female hamsters have an extremely short estrus cycle. They will go into heat and will be fertile every four days. Compared to other mammals, this is remarkable – human women ovulate every 28 days (we can consider this “going into heat” for the purpose of illustrating reproduction), while female dogs will go into heat every six months.

If you miss the opportunity to breed your female dog during her heat cycle, you will need to wait for another half year. If you miss the opportunity to breed your female hamster, you only need to give it another few days.

This is one of the reasons that it is crucial to keep only same-sex pairings when keeping hamsters unless your goal is to breed. If you keep a male and a female hamster together for as little as a few days, you will likely end up with an unintended pregnancy (more on the likelihood of a female becoming pregnant in a single heat cycle below). 

Female hamsters return to heat quickly after birth

You may think that a new mother might be given a break from her heat cycle after the birth of her litter, but when it comes to hamsters, you would be wrong. Incredibly, female hamsters can go into heat in as little as 24 hours after giving birth to a litter.

This means that a hamster can theoretically become pregnant again in as little as a day and a half after her previous pregnancy has ended. 

Hamsters have a short gestation period

There is a lot that goes into the forming and the growing of a living being, and female hamsters are able to accomplish this feat in a mere 16-22 days (the reason for this relatively large range is in the difference between species – Syrian hamsters have a gestation of 16-17 days, while dwarf species can gestate for as long as 22 days). 

While this seems an impossibly short period of time, we also must take into consideration the condition of the pups when they are born. The gestation period of a horse, for example, is 11-12 months. At the end of the pregnancy, a fully-developed foal is born, able to see and hear immediately and able to stand and walk within hours.

On the other hand, we have the hamster. Hamster pups are born after a matter of weeks significantly under-developed. They are born blind, deaf, hairless, and immobile.

If you look at pictures of a newborn hamster pup, you will see they look like they should still be in their mother’s womb. This is not to say that a hamster would need to gestate for 11 months to have a fully developed newborn (the baby would have lived half his life in the womb if this was the case), but it is of note as we wonder how a mammal can possibly gestate for such a short period of time.

Male hamsters are highly motivated to reproduce

You could probably apply this attribute to the males of most mammal species, but the desire to reproduce coupled with the rapid ability at which to do so makes the male hamster particularly fecund.

Not only will the male hamster place all of his focus on a female in heat, but it will take him only a few seconds to get the deed done. When a female hamster goes into heat, she will remain fertile and receptive to mating for around 12 hours during the evening and night, which is the hamster’s most active time of day.

If a male hamster takes only seconds to impregnate a female (if all goes as planned), it is no wonder that in a single evening of spending time with a male, a female in heat will have a very high likelihood of achieving pregnancy.

Hamsters have large litters

Finally, litter size has a lot to do with the ability of a hamster to produce so many pups per year. The average size of a hamster litter is between six and eight pups, but this is not a hard limit.

Hamsters frequently produce litters of twelve or even fifteen pups, and the real over-achievers are capable of producing as many as twenty pups in a single litter.

Let’s do a couple of calculations just for fun – if a female hamster regularly produces fifteen pups per litter, and she produces eighteen litters in a year (the maximum amount of litters a female can possibly produce annually), she would be capable of having 270 pups in a single year.

If a female produces twenty pups per litter, at eighteen litters per year, that would equal 360 pups in a single year. It is challenging for us humans to even comprehend a single hamster pair producing that many offspring. 

At What Age Can A Hamster Have Babies?

Hamster pups typically stay with their mothers for 21 days before they are weaned and able to leave the nest, but there is another milestone that a hamster pup can reach as young as 21 days of age, and that is fertility.

While many female hamsters will remain sexually immature for up to two or three months of age, Syrian hamsters especially can reproduce in as little as three weeks of age.

If you do find yourself with a planned or unplanned hamster breeding, it is important that you separate the pups by gender by three weeks of age or as soon as they are weaned – otherwise, you may find yourself with several more unplanned litters. 

On the flip side, a hamster will become too aged to produce healthy offspring at a seemingly young age as well – it is advised against breeding any female hamster after she has reached 15 months of age.

This may seem young, but it is important to keep in mind that the average lifespan of a hamster is only around 1.5-2.5 years old. A male hamster, on the other hand, can remain fertile and can be used for reproduction for the entirety of his life. 

Hamsters Have Fewer Babies In The Wild

Finally, we should mention that the figures we are providing are strictly referring to hamsters living in captivity. In the wild, hamsters tend to be seasonal breeders. Female hamsters in the wild will usually only go into heat in the Spring and Summer months so that their hair-less, vulnerable babies are born with the elements on their side. As the days shorten and the temperatures drop, most female hamsters in the wild will cease their cycles. 

In captivity, this is not a consideration in most households and breeding facilities. Most pet and breeding hamsters are kept indoors only, where the temperature remains constant and mild.

And when a hamster is indoors, he or she is usually exposed to artificial lighting. With the indoor temperature and the indoor lights, pet and breeding hamsters won’t be able to differentiate between seasons and will go into heat throughout the year.

Does 144 Hamster Babies Seem Like A Lot?

If 144 hamster pups seems like a dizzying number, we only need to consider that this is taking into account the average litter size only (at the maximum number of annual breedings, of course).

When we do the calculations for hamsters with above-average litter sizes, the numbers become even more astonishing. Between the variety of factors involved in hamster prolificacy, we begin to understand the wide perceptions about how rapidly hamsters, and most rodents, reproduce.

While the well-known saying is “breeding like rabbits” when referring to prolificacy, in all truth, that saying can apply to almost all rodents. You can learn more about hamsters and other small pets in my latest articles here!