Sloths have somewhat peculiar and hard-to-predict sex lives -- they don't necessarily have a traditional mating season, and they don't mate for life. Females reach sexual maturity before males do, and when they're ready to find a mate and get down to breeding, they make their desires known vocally. Extremely vocally.
Screaming and Shouting
Female sloths find their mates when they're ready to breed, and they do it by beckoning mates to come to them. A female sloth in heat screams to attract males, which will journey toward the source of the noise in pursuit of a mate. Once males get there, they may fight each other for her affections -- sloths have been found to be territorial, and some bear scars from mating-related scuffles.
A male sloth seeks his mate by following her calls. Once he finds her and does his part, he doesn't necessarily stick around -- male sloths are notably promiscuous, known to mate with several females at a time within an area. The females aren't monogamous, either, mating with multiple males and siring offspring from a selection of sloths. Meanwhile, even though sloths may become territorial and fight one another over females ready to mate, their infamously sedentary nature prevents any one sloth from effectively monopolizing the female population in a given area.
Female sloths are sexually mature at about 3 years of age; males follow suit at the age of 4 or 5. When they mate, they produce only one child after a pregnancy that can last up to 10 months -- even sloth gestation procrastinates. After the baby is born, it is fairly dependent on the mother for up to 9 months. After birthing a child, a female sloth waits 14 to 16 months before mating again.
The Single Life
When they aren't mating, sloths generally live alone -- they don't form family units such as gorilla populations do. Instead, the males generally isolate themselves until they hear the mating call of a female. Females sometimes group together but are also known to live solitary lives. The notable exception is that, after birthing a child, a female and her offspring will remain close for the baby's first two years of life, after which it ventures off on its own and starts its own life.
- Apfel ist lecker. image by sector12 from Fotolia.com