rabbits in cold weather

Wild rabbits will start breeding around late March or early April and continue through August and September. During these months a female can produce several litters due to relatively short gestation periods of roughly 4 weeks (or about 31 days give or take). Rabbits do have babies in the winter, however, sometimes breeding is delayed if the female rabbit’s body mass has been negatively impacted due to harsh conditions and limited resources. There are lots of conditions that impact when rabbits breed and when their offspring are born. I'm going to take a look at the key issues to understand about rabbit babies being born in the winter. About the Rabbit Breeding Process Females become sexually mature at 5-6 months of age. In the wild kittens are cared for by their mother for about the same time they were in her womb – four weeks (but sometimes as little as two weeks). This allows the mother to no longer have to expend her energy caring for her young. Females can very soon become pregnant again after giving birth which results in multiple litters per season which can range from 3 to 12 kittens in each litter [Source]. Unlike a lot of the animal kingdom, female rabbits don’t “come into heat” [Source]. You will hear of female dogs going into heat if they are not spayed and wearing diapers around the house. Female horses also go into heat and can be quite moody and harder to handle by their owners during this time. Rabbits do not go into heat, which allows them more opportunities to breed whenever a mate is available. Because rabbits are free to mate all year round, their population size can remain quite stable or even increase exponentially certain times of the year. This can be quite advantageous to the survival of rabbits. Rabbits live in colonies which act together as a group to warn each other of danger and to safely forage during times of plentiful resources. Having this continuous breeding cycle is helpful as there is power in numbers. However, during times when resources are scarce, colonies can find they are competing between themselves for adequate food and water How Weather Affects Rabbit Breeding: The Cold During the winter months, food and water may become scarce. This can cause females to have litters that naturally are not healthy and that may not fare well in winter months causing increased mortality. Wild rabbits naturally have shorter lifespans than domesticated rabbits. Especially over the winter season, mortality rates from multiple scientific studies average around 30% [Source]. Due to food availability, bad weather, and predators who are also trying to stay alive during the winter months, female rabbits may not survive the winter to reproduce or may not reproduce healthy offspring. This may explain the evolutionary advantage to the low gestation period and high rate reproduction rate as a mechanism to offset high mortality during the winter months. Rabbits will spend much of their time underground or undercover/shelter during the colder months. It is in these habitats that they are shielded from wind and snow and can remain close to dry earth to keep warm. They also rely on the members of their colony to keep them warm by cuddling up together. In order to deal with extremely cold temperatures, their body naturally kicks up a notch to maintain their homeostasis. In order to keep up with these increased demands, rabbits need to eat more to have the extra calories to spend. Rabbits may need up to three times their normal caloric intake in order to be in good health and keep warm. How Weather Affects Rabbit Breeding: The Heat The summer months can also be unkind to wild rabbits. Very high temperatures can cause sterility in bucks (male rabbits) temporarily, or longer (60 to 90 days) in older bucks [Source]. This is why you may not see many rabbits out and about on very hot days as they tend to try to remain cool in the dirt or burrows when possible. You will mostly see them out at dawn or dusk when the temperatures are milder. Rabbits, both male and female produce considerable heat naturally as a byproduct of digesting copious amounts of fiber- which makes up the good majority of their diet. In hot weather, it is hard for them to get rid of this heat. To compensate, they tend to eat less. When females are nursing, they expend a lot of calories. If the temperatures are extreme, she will naturally eat less which will also decreases her milk production. This decrease in calories available to newborn bunnies will reduce their growth and ultimately lead to lower weight and growth rates of these babies overall. These bunnies will leave the care of their mother at lower weights which could make them weaker and more vulnerable to predators [Source]. In warmer weather, all animals are thriving including predators. Mortality of rabbits during this time of the year remains stable as most of the rabbits are healthy, able to outrun their predators (at times) and there is plenty of other food sources for predators available. Believe it or not, wild city rabbits end up having better overall survival rates than rural rabbits due to additional resources, less competition for those resources, and a decrease quantity of natural predators. So not all wild rabbit populations have a significant decline in the winter, but they are overall higher than in the spring and summer months. When Rabbits are Born Before giving birth, mother rabbits will usually try to find a dry, warm, and secluded area to make their nest and ultimately give birth. The nest is usually made of vegetation and leaves and lined with the mother’s fur to keep her babies warm. Rabbits are born hairless, with their eyes and ears shut, and are very easy prey if not well hidden. Despite being virtually helpless, mother rabbits aren’t fawning over their babies every hour of the day. The mother must have an adequate nest that not only keeps her babies warm and dry but keeps them safe as she is only there to feed them for a few minutes once or twice a day. This not only keeps mom healthy and strong so she can care for her young but avoids drawing too much attention over to the nest which could attract unwanted predators. Mothers come back to their nests usually during the dusk and dawn hours to have the best chance of caring for their babies unnoticed. At around 3 weeks old, babies are weaned and become independent of their mother and forge on their own. If you see babies that are furry with their eyes open, they are likely to be on their own and will be fine in doing so. This allows the female rabbit to re-focus her attention on her own individual health and calorie intake. Additionally, this adds more functional members to the colony which improves the survival of the colony as a whole and allows more opportunities for breeding. What If I Find Baby Rabbits in the Winter? Just because not all rabbits have babies in the winter, doesn’t mean you can’t come across a nest. Just because mom isn’t around, doesn’t mean you should raise the alarm. Chances are the babies are just fine and are huddling together for warmth. More than likely they are actually well protected from the elements as the location is probably out of the wind and lined heavily with organic materials and the mother’s fur. It’s best to just turn around and go on your merry way and not to disturb the nest or the babies. If you’re concerned, you can put something non-obstructing in front of the nest, but nothing that would cause the mother to not be able to get to her babies. You can put a line of white flour or a string; something that can be easily noticed if disturbed [Source]. If you go back in around 12-24 hours and see the flour has been dispersed or your show lace has been moved out of wack, chances are you have missed mom on her quick pit stop back to her babies. I Found a Baby Rabbit Far from Home If you happen to find a baby bunny, not in the nest, you can try to locate the nest and place the bunny back with their brothers and sisters. You want to do your best to intervene as little as possible and handle the baby as little as possible. Babies must be warm to reunite with their mothers. This could be an evolutionary trait that mothers adapted to put their most energy into their healthy offspring. Usually animals being cold is a sign of poor health and potential illness, so mothers are less likely to continue care of that offspring as the chances of survival are much less. So do your best to warm baby up and keep them warm until you can find the nest. Secondly, it’s best to not handle the baby directly with your hands if at all possible. One reason is because your can transfer your scent onto the baby which would also impact the mom accepting the baby back, but also because rabbits can carry tularemia. Tularemia is an infectious bacterial disease that can affect humans [Source]. So although you are doing your good deed of the day, proceed with caution Orphaned Rabbits After 12-24 hours of waiting without any sign of mom, it may be safe to say that she is not coming back. If the area looks untouched for more than 24 hours it may be wise to take the baby (or babies) to a wildlife rehab or rescue. As much as you may want to have adorable babies in your home, most people don’t have the supplies or knowledge to properly care for newborn bunnies. The best thing you can do is keep the bunnies warm and get them to a rehab center as quickly as you can. You may want to, but do not give the bunnies anything to eat or drink unless instructed to do so by the wildlife rehab. Rabbits in general have very sensitive digestive systems, especially when they are young. Trying to help in this way may actually bring more harm to the babies than good [Source]. Are Baby Rabbits Booming in the Winter? According to a study by the Canadian Journal of Zoology, “…females with lower winter body mass started to reproduce later, but we did not find any effects on litter size and mass”. [Sourcehttps://www.canr.msu.edu/resources/rabbit_tracks_breeding_techniques_and_management] Depending on where the rabbits live and what type of habitat they live in, could impact how well their fair in the winter. Also the rabbit’s overall health going into the winter could also impact their survival and thus their ability to mate and give birth. It seems rabbits reproduce and have babies in the winter, sometimes just with a delay. If the female rabbit survives the harsh winter, one may think she has a hard time bouncing back and may have issues with reproduction. Luckily, it seems as though wild rabbits are pretty resilient and if they were healthy enough to survive the winter, the body weights and number of offspring the rabbit has next is not reduced. So next time you see a bunny out in the cold, chances are they are doing just fine (...that is wild rabbits)! Of course, if you see a rabbit that is clearly thin, dehydrated, or injured – feel free to come to the rescue. Babies can be born in the winter and in a few weeks they’ll be playing in the snow and leaving tracks all over your lawn! So no need to worry, let it snow, let it snow, let it snow!