LibGuides: Two-toed Sloths (Choloepus spp.) Fact Sheet: Reproduction & Development

Courtship

(Based on observations in managed care)

Mating occurs throughout the year, though some observers detect a marked mating season in March and April
Females in estrus appear to initiate mating (Meritt 1985)

Reproductive rate

Gestation

Birth

Litter size: one
Weight: 340-400 g (about 12-14 oz)
Length: 25.4 cm (10 in)
Mother gives birth on ground or in upside down, hanging position; infant grabs onto her fur and makes its way to her chest to nurse
Milk is higher in fat (6.9%) and protein (61%) than cow's milk

Infant (< 1 year old)

Infant is born alert and strong, eyes open teeth present, claws fully formed. Gripping reflex enables it to climb to mother's abdomen. Nuzzling and suckling by newborn stimulates release of milk — usually within 48 hours
Newborn nurses for 15 days for male infant, 27 days for female
Play behavior observed at 15-19 days
First hangs upside down at 20-25 days, and regularly feeds away from mother at 5 months
Young of all species cease nursing at about a month old, but may take leaves even earlier
Young are carried on mother's abdomen for six to nine months and feed on leaves they can reach from the position
By 6 months, elimination occurs in adult manner
May keep a close association for up to two years

Adult

Two-toed sloths reach sexual maturity at approximately three years of age (females) and four to five years old (males)
External genitalia small and inconspicuous (sexing is difficult)

Hunted by jungle cats (jaguar, ocelot) and birds of prey (especially Harpy Eagle)
Humans hunt them for meat and pelts
Deforestation is also a threat

A young sloth is weaned relatively early, but stays with its mother for a long time.

Eisenberg and Maliniak (1985)
Meritt (1985)
Nowak (1999)
Taube (2001)