Brown-throated three-toed sloths are thought to be monogamous. Females vocalize to attract males when they are ready to mate. Females typically mate with the first male they encounter. Although it is unclear if they have a defined breeding season, evidence suggests mating occurs just prior to the rainy season. Copulation lasts 10 to 15 minutes and takes place in the female's tree, approximately 15 m above the ground. During copulation, the male positions himself behind the female. Once mating is complete, the male leaves shortly there after.
Mating System: monogamous
Once copulation is finished, males immediately leave and do not provide any parental care to young. Bradypus variegatus gives birth to a single offspring once a year. During gestation, which lasts for 5 to 8 months, the mother does not make any preparations, such as nest-building. After birth, neonates are held ventrally, which is thought to help provide protection for young, including attack from predators. Neonates weigh less than 1 kg at birth. Most individuals become independent once weaning is complete, which takes approximately 4 months. Females become reproductively mature by 3 years of age, and males become reproductively mature between 3 and 5 years of age, with an average of 4 years of age.
Breeding interval: Brown-throated three-toed sloths breed once yearly
Average number of offspring: 1.
Range gestation period: 5 to 8 months.
Average birth mass: less than 1 kg.
Average weaning age: 4 months.
Range time to independence: 2 to 4 months.
Average age at sexual or reproductive maturity (female): 3 years.
Range age at sexual or reproductive maturity (male): 3 to 5 years.
Key Reproductive Features: year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization ; viviparous
Brown-throated three-toed sloths give birth on the ground or in trees. During birth, the mother pulls the infant between her hindlegs, and other sloths aid in the birthing process by cleaning the mother and infant and by ensuring that the infant doesn't fall. Mothers help young establish motor behavior, posture, learning development, and independent exploration in young. Paternal care is thought to be non-existent in this species.
Parental Investment: female parental care ; pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Provisioning: Female, Protecting: Female)
- Bezerra, B., A. Souto, L. Halsey, N. Schiel. 2007. Observation of brown-throated three-toed sloths: mating behaviour and the simultaneous nurturing of two young. Japan Ethological Societ, 26: 175–178.
- Gilmore, D., C. Da-Costa, D. Duarte. 2000. An update on the physiology of two- and three-toed sloths. Brazilian Journal of Medical and Biological Research, 33: 129-146. Accessed February 22, 2011 at http://www.scielo.br/pdf/bjmbr/v33n2/3528c.pdf.
- SOARES, C., R. CARNEIRO. 2002. SOCIAL BEHAVIOR BETWEEN MOTHERS ´ YOUNG OF SLOTHS Bradypus variegatus SCHINZ, 1825 (XENARTHRA: BRADYPODIDAE). Brazilian Journal of Biology, Volume 62, Issue 2: 249-252.