Depending on his/her genetic makeup, a rabbit will reach sexual maturity somewhere between the age of 3 to 8 months. Once the sex hormones start flowing, expect to see behavioral changes. Some may be cute: a sexy rabbit may circling your legs, honking a little love song, be very needy and cuddly and follow you around incessantly. Other puberty-related behaviors are not so cute: a honking, singing bunny circling your legs who finishes the symphony with a flourish of urine spray and then sits there looking up at you for approval of this sign of unconditional love. And some hormone-related phenomena are simply dangerous to your bunny: unspayed, unbred female rabbits have a very high risk of uterine cancer.
Although not all rabbits exhibit objectionable behaviors upon reaching sexual maturity, many (if not most) do. One can expect to see the following behaviors once those sex hormones kick in:
Opposite sex pairs will begin reproducing as soon as they mature. Left unchecked, an unspayed rabbit and her intact female descendants can produce more than 1300 offspring in a year. Over the course of five years this number balloons exponentially to more than 94 million! (If you don't believe me, check out the calculations.)
A well-meaning, if naive, person might think it's a simple matter to find homes for those babies born so that a female rabbit could be bred "just once" or "so the kids can witness the miracle of birth" (For a balanced view, be sure to take the kids on a field trip to the local animal shelter's euthanasia rooms so they can also witness the "miracle of death".).
Finding a safe forever home for a rabbit is not simple.
Thousands of sweet, perfectly wonderful rabbits (purebred and mixed breed alike) are abandoned at shelters every year, and perhaps an equal or larger numbers are "set free" in parks or neighborhoods to face an death from predators, disease and starvation. For every rabbit produced by a casual breeder, another is put to death at an animal shelter or dumped in a park to die, because there are simply not enough homes for all of them.
Unspayed female rabbits have a very high risk of uterine cancer. Our vets commonly see uterine changes and tumors in unspayed rabbits as young as eighteen months. As the bunny ages, her risk increases, and our experienced rabbit vets report that many, if not most, rabbits older than about four years who are brought in for spaying reveal uterine changes and/or tumors. A rabbit's reproductive system is evolved for constant reproduction over a relatively short lifespan. When reproduction is thwarted, but the uterus is left intact, the system can go a little haywire. It's not unexpected.
Unspayed rabbits, and rabbits who are spayed late in life also face an increased risk of mammary cancers, though these are less common than uterine cancers.
Upon reaching sexual maturity, male rabbits often begin displaying mounting behavior (on your shoes, the cat, stuffed toys, your leg, your sleeping head...), marking territory with urine and producing a musky sex odor. Male rabbits, like females, can become very aggressive when the testosterone kicks in, and the only truly viable solution for this problem is castration, also known as neutering.
Testicular cancer, while far less common than uterine cancer, does occur, usually in older rabbits. Neutering eliminates this risk.
How can spaying/neutering help?
Modern rabbit medicine is far more sophisticated than it was even ten years ago, and many excellent vets are now spaying and neutering thousands of rabbits a year without incident. Still, no surgery is 100% risk-free, and each rabbit caregiver must make the decision to spay/neuter on an individual basis, in consultation with an experienced rabbit veterinarian. But there are plenty of reasons to spay/neuter your rabbit.
Thousands of rabbits are abandoned every year when they outgrow their Easter Bunny cuteness. You will never have to worry if your rabbits offspring will suffer a terrible death after being abandoned in the wilds of suburbia, being dumped at a pet store to be sold as snake food or being euthanized at an animal shelter if you don't contribute to this problem.
And just so you know....
Don't Abandon Your Bunny: Spay/Neuter!
Our domestic rabbits (Oryctolagus cuniculus) are derived from an ancient line of the wild European rabbit. European rabbits live in warrens (a series of underground tunnels excavated by family groups) in an established territory. A domestic rabbit who has been abandoned in a park that looks inviting and safe to a human has been sentenced to a cruel death
A domestic rabbit depends on human care. No matter how appealing a "natural" environment appears to a human, the most likely outcome of a rabbit turned loose there is suffering and death. Before you consider abandoning your companion rabbit to "the wild" or to a shelter when he or she matures and becomes willful and difficult to manage, give him or her a fair chance to be a wonderful companion: have him/her spayed or neutered. You will experience one of the most delightful, intelligent, loyal, affectionate and entertaining friends you could hope to know.