Squirrels mate one to two times per year, depending on the species. They mate in the early spring and summer. The average litter size is between two to four, with a gestation period of 30–45 days.
Did you know that many species of female squirrels are only fertile for a few hours? This causes a bit of frenzy amongst squirrels.
This also begs the question, are the squirrels in your garden chasing each other for fun, or is it a mating chase?
In this article, we answer all your questions about how squirrels mate, how many times a year they breed, what time of year they have their babies, and more.
How Do Squirrels Mate?
Squirrels mate after a male outcompetes other males to mate with a fertile female. Once the female approves of him as a mate, the male mounts the fertile female.
During squirrel breeding season, male squirrels perform mating rituals. These include competing, chasing, and mating dances.
Once the female has decided to accept a mate, she allows him to mount her and copulation occurs.
The mating ritual of squirrels can include males competing with other males. Males can also start following females for days before is ready to mate. Males chase females. The winning male guards the female against the other males.
When a female accepts a male, she allows him to mount her.
Copulation is relatively quick, often lasting less than 30 seconds. After completion, a plug forms. Female squirrels are known to pull out these plugs immediately so they can mate with other males.
How Do Eastern Gray Squirrels Mate
Eastern gray squirrels (Sciurus carolinensis) are one of the most common types of squirrels in North America and many parts of the world.
During their breeding season, males compete to mate with female eastern gray squirrels. It starts with the males following females five days before estrus.
Estrus is when a female squirrel is fertile and ready to mate.
In Eastern gray squirrels, estrus lasts less than 8 hours. During estrus, the female’s vulva appears enlarged and pink vulva.
Copulation lasts less than 30 seconds, and females can mate with more than one male.[1]
How Do Eastern Fox Squirrels Mate?
Fox squirrels (Sciurus niger) are loners, but they gather together during mating season. Males move into the home range of a female that begins estrus.
Male squirrels threaten one another with their posture, forming dominance hierarchies. A few males chase one female, and the winning male guards the female from the other males.
Like eastern gray squirrels, fox squirrels’ copulation lasts less than 30 seconds and can be accompanied by barks and high-pitched whines.
A copulatory plug forms after mating. Females often remove this so they can mate with several males.[2]
How Do Red Squirrels Mate?
Red squirrels (Tamiasciurus hudsonicus) are territorial. Males invade the territory of a female when they are in estrus and the mating chase begins.
A single dominant male chases a female. He drives off the competition with vocalizations or chases them off.
Red squirrel females’ period of estrus only lasts a day. She will mate with the male she has chosen several times on that day.
The male and female groom before and after copulation. After copulation, the male returns to his territory.[3]
According to Kluane Red Squirrel Project researchers, female red squirrels mate with up to 14 partners in a day.[4]
The Kluane Red Squirrel Project has been monitoring red squirrels in Yukon since 1987.
How Do Flying Squirrels Mate?
Male southern flying squirrels (Glaucomys volans) gather around a fertile female and compete for her attention with a type of mating dance. The males rapidly move their hind quarters back and forth and kick their hind legs.[5]
The female will choose and mate with the dominant male.
When Is Squirrel Mating Season?
Most squirrels mate in spring. Some squirrel species mate twice a year – once in spring and again later in summer. Eastern gray squirrels mate in winter and in spring.
| Species | Litters per year | Mating Season |
| Eastern Gray Squirrels | 2 | December to February and May to June. |
| Eastern Fox Squirrels | 1 | Between December and June |
| Red Squirrels | 1–2 | Late winter to early spring and late spring to early summer. |
| Ground Squirrels | 1 | Spring |
| Flying Squirrels | 2 | February to March and May to July |
When Do Eastern Gray Squirrels Mate?
In North America, eastern gray squirrels mate in winter (December-February) and in spring (May-June).
The females begin their reproductive life at 1.25 years old. Males are sexually mature earlier, by 11 months of age.
Most of the year, the male testes are inactive and only weigh 0.03 ounces. During the breeding season, their testes weigh 0.2 ounces.
When Do Eastern Fox Squirrels Mate?
Fox squirrels mate in December and June.
When Do Red Squirrels Mate?
Red squirrels breed once or twice a year.
In the southern and eastern parts of North America, red squirrels mate twice a year. Females birth a litter in spring and a second litter in late summer.
Further north, red squirrels breed in spring.
Females are in estrus only one day per breeding season. Conception usually occurs within a few hours of mating.
When Do Ground Squirrels Mate?
Ground squirrels mate in spring, shortly after emerging from hibernation.
For California ground squirrels, thirteen-lined ground squirrels, and Arctic ground squirrels, the breeding season starts in early spring.
A study on thirteen-lined ground squirrels (Ictidomys tridecemlineatus) indicates that females start estrus within 24–48 hours after emerging from hibernation. [6]
Male California ground squirrels (S. beecheyi) have abdominal testes that drop into a temporary scrotum during the breeding season.
After 8 months of deep hibernation, male arctic squirrels (Urocitellus parryii) merge. Females emerge a few days later. For about two weeks, males barely have time to eat as they battle rival males to maintain territory.
Shortly after females emerge from hibernation, they are ready to mate. Female chirp to call a nearby male as she doesn’t have time to waste. They are only fertile for 12 hours in the year.
Once she has accepted a male, he will stay with her for 24 hours to protect her from other males.[7]
When Do Flying Squirrels Mate?
Southern flying squirrels breed twice a year: once in early spring between February and March, and again in the summer between May and July.
The testes of a male southern flying squirrel are abdominal until the middle of January. Here, they drop and become scrotal in time for the breeding season in spring.
A membrane covers the opening of the female flying squirrel’s vagina which disappears when breeding season starts.
Female southern flying squirrels born during spring can reproduce the following spring until they are 3 years of age. After 3 years of age, they are no longer fertile.
When Do Squirrels Have Babies?
Squirrel babies are born twice a year, between 30 and 44 days after mating. The first litter is born between late February and March, and the second litter is born between June and July.
The gestation period of squirrels differs depending on the species. Their mating season also varies slightly, meaning different squirrel species have babies at different times of the year.
Squirrel Gestation Period
The gestation period of tree squirrels ranges from 30-45 days, depending on the species of squirrel.
The gestation period for eastern gray squirrels is 44 days. Newborns are born naked, blind, and weigh a mere 0.4 -0.6 ounces. [1]
Gestation lasts 44-45 days for fox squirrels. Females give birth to 2-3 infants, also known as kits.
Red squirrels’ gestation lasts an average of 35 days. A female red squirrel can give birth to 1 to 8 kits.
The gestation period for California ground squirrels is about 30 days or one month. The average gestation period for female southern flying squirrels is 40 days.
| Squirrel Species | Gestation Period |
| Eastern gray squirrels | 44 days |
| Fox squirrels | 44-45 days |
| Red squirrels | 35 days |
| California ground squirrels | 30 days |
| Southern flying squirrels | 40 days |
How Do Squirrels Avoid Mating With Siblings?
Squirrels use smell to detect whether other squirrels are their relatives or not. This helps them avoid breeding with a sibling.
When squirrels meet, they seem to kiss, nose to nose. But what they are actually doing is smelling each other.
According to Jill Mateo, a researcher at The University of Chicago, there is
a gland in the skin in the corner of their mouths. Squirrels can smell if they are related by whiffing this glad.
This helps avoid inbreeding.[8]
How Squirrels’ Mating Behavior Changes
During mating season, squirrels become more active, social, and vocal and take part in mating rituals like mating chases and mating dances.
If you happen to notice more squirrels in an area, and they are noisier than usual and often chasing each other, it can be signs that its squirrel breeding season.
Here are squirrel behavioral changes that occur during breeding season:
- Squirrels gather together.
- Squirrels vocalize more than usual.
- Squirrels can be seen chasing each other more than usual.
- Squirrels can be observed grooming genitals often.
- Flying squirrels perform a mating dance
Squirrels Gather and Get Chatty
During mating season, squirrels that tend to be antisocial (like eastern fox squirrels) and territorial (like loner red squirrels) convene and form social hierarchies.
The males compete through vocalizations and postures to show their dominance.
Squirrels Chase Each Other
Males pursue a fertile female in a mating chase. The winner guards her against other males. He does this with vocalizations or by physically chasing rival males away.
Squirrels Take Grooming Up a Notch
Part of the courtship between the males and females looks like playfighting and some squirrels vocalize during copulation.
Before and after the mating, you can witness male and female squirrels often grooming their genitals.
Flying Squirrels Twerk To Impress
If there are southern flying squirrels in your area, and you don’t mind staying up late, you can get a chance to witness their nocturnal mating dance.
The male squirrels gather around a female and rock their hind quarters back and forth. You call it ‘squirrel twerking’ if you like.
Do Squirrels Stay Together After Mating?
No, male and female squirrels do not stay together after mating. After all of the mating rituals and mating, the male and female squirrel part ways.
Squirrels do not mate for life or raise their young together.
In fact, after the male parts, a female can mate with other males before concluding a successful mating season.
She will give birth to a litter of kits 30 – 45 days later, depending on the type of squirrel. It is possible that the kits will have different fathers, but they won’t grow up knowing one as the males do not get involved with raising their young.
