Female three-fingered sloths come into estrous, or heat, multiple times a year and boy, do they like to scream about it! When a female sloth is "in heat" and ready to breed she doesn't wait for the males to come to her, she actively encourages them with high-pitched screams. The males will then follow the sound of the screams until he finds her. However, if multiple suitors find her, they may fight each other until the strongest male wins the right to mate. Once decided, the female will let the male approach. In a matter of minutes, intercourse is finished. In some cases, a pair has been found to stay together in the same tree for a few days, sometimes mating again. In others, the male has left shortly after fulfilling his role. Both genders are promiscuous and are likely to mate again.
The female three-fingered sloth's pregnancy will last 6-7 months (for two-fingered it is 10-11 months!) and typically only one baby is born, although on some occasions, twins have been reported. Not a lot is known about the courting and reproduction of sloths as it has only been recorded on rare occasions. Recently, our resident three-fingered sloth, Bella, was in heat and we were lucky enough to witness her mating calls, although we're not sure the neighbors would share the sentiment.
By former intern Katie Grant | Read more articles like this one by subscribing to our newsletter!