There are two extant families of Sloth that are still in existence today One of these families consists of two-toed sloths, and the other three-toed sloths. Within these families there are many species, all of which live in the regions of Central and South America.
The two-toed varieties of sloth are are slightly larger than the three-toed variants and the is the largest type of sloth alive today. They can grow up to 58-70 cm, and a weight of 4-8 kg. The largest land sloth to have ever existed though, was a species know as the Giant Ground Sloth (Megalonyx jeffersonii), of the Megalonychidae family. This giant could grow up to around 10 feet and 2200 lbs – around the size of a bull or an adult ox.
In this blog we want to take a look at the answering how long do sloths live? To identify if there is any difference or common life expectancy across the Species.
How Long Do Sloths Live?
The average lifespan of Sloths varies depending on the species.
The average lifespan of two-toed sloths in the wild is still to be widely studied and is currently unknown, but in captivity the average is around 20 years.
On average, three-toed sloths live longer, up to 25-30 years in the wild.
Two species are included on the IUCN Red List as threatened or vulnerable. The Pygmy sloth is listed as critically endangered and the maned sloth is listed as vulnerable.
Types and Species of Sloth
All Sloth belong to the order ‘Pilosa’ and the suborder ‘Folivora’. There are two types (families) of Sloth, and within these types there are six species:
- Genus Bradypus (Three-toed sloths)
- Pygmy Three-toed Sloth (Bradypus pygmaeus)
- Maned Three-toed Sloth (Bradypus torquatus)
- Pale-throated Three-toed Sloth (Bradypus tridactylus)
- Brown-throated Three-toed Sloth (Bradypus variegatus)
- Genus Choloepus (Two-toed sloths)
- Linnaeus’s Two-toed Sloth (Choloepus didactylus)
- Hoffmann’s Two-toed Sloth (Choloepus hoffmanni)
- Common Name: Sloth
- Scientific Name: Bradypodidae or Megalonychidae
- Type: Mammal
- Diet: Herbivore
Of the 4 species of three-toed sloths that are extant today, two are listed as either vulnerable or critically endangered. Locations of habitat vary across South and Central America, with some encompassing as little as a few miles, to other spanning many countries.
Pygmy Three-toed Sloth (Bradypus pygmaeus)
The Pygmy Three-Toed Sloth is endemic to a small island off the coast of Panama. It can be found exclusively in the red mangrove swamps of this island, Isla Escudo de Veraguas. It is much smaller than the other three varieties of the Bradypus Genus averaging 48-53 cm in length and 2.5 to 3.5 kg in weight.
The Pygmy sloth, also known as the Monk Sloth or Dwarf Sloth is one of the varieties to host algae within their fur. The fur provides the algae a place to thrive, while the algae provides camouflage for the sloth, in what is a symbiotic relationship.
This species was only recorded in 2001 and so far, most likely due to the fragility of population and very small, remote habitat (1.7 square miles), reproductive and mating behaviours, have not yet been documented. It is yet unknown how long they live in the wild.
This critically endangered species is listed as one of the 100 most endangered species in the world. Populations at last census in 2012 were as low as 79.
Maned Three-toed Sloth
The Maned sloth can only be found in the Southern Brazilian Rainforest along the Atlantic coast. Deforestation has pushed it out of habitats further north, and remains a threat to the existence of its remaining habitat. This sloth is listed as vulnerable on the IUCN Red List.
Adults measure around 55–72 cm and weigh around 4-7.5 kg though females may be slightly larger. They have dense black and white undercoat, and an outer coat that varies between shades of pale brown and grey.
Some sources advise a 12 year life expectancy for the Maned sloth in the wild, while others suggest 15-20 years. Detailed studies of the lifespan and expectancy of a Maned sloth have yet to be formally documented.
Pale-throated Three-toed Sloth
The Pale-Throated Sloth is found throughout the forests of northern South America. Particularly in:
- Brazil (only north of the Amazon River)
- French Guiana
- Venezuela (East)
This species is not considered to be vulnerable, and is listed as least concern.
Pale-Throated sloths are herbivores, eating only buds from trees, leaves and debris such as twigs. These are another species of sloth that live symbiotically with algae, which is hosted on the surface of the outer coat (guard hair).
The difference between females and males is quite noticeable with this species. Males average around 45-55 cm in length while Females can reach 50-75 cm.
Pale-Throated sloths look very similar to Brown-Throated sloths, but can be distinguished by a a pale patch on their throat. The rest of their fur appears a blackish grey, with a thick guard coat but males will also have an orange patch on their back.
They reach sexual maturity between 3 to 5 years old and while no extensive study has been carried out on the lifespan of the Pale-Throated species, three-toed sloths in general tend to live between 25-30 years of age.
Brown-throated Three-toed Sloth
The Brown-Throated Sloth can be found throughout South and Central America. It is the most common of the Bradypus three-toed sloth species.
Males and females reach a similar size and weight, between 42-80 cm in size and 2.25-6.3 kg in weight. Unlike other species, both males and females will grow to the same size. The Brown-Throated Sloth looks very similar to the Pale-Throated variety, but with a lighter guard coat and a brown patch on the throat.
The average life expectancy for the Brown-Throated sloth is between 30-40 years in the wild. It is one of the few species that have been studied widely, most likely due to the size and range of the population. This sloth is listed as a species of least concern.
There are two distinct species of two-toed sloth, neither of which is listed as a species of concern. They tend to be larger than their three-toed cousins, with longer fur and no tail. They also have a more defined nose.
Linnaeus’s Two-toed Sloth
Linnaeus’s Two-Toed Sloth live in many countries across South America, including:
- Brazil (Similarly to the Pale-Throated Sloth, north of the Amazon River)
- Bolivia (Possibly)
- The Guyanas
While this species is listed as of least concern, populations are declining due to habitat loss through deforestation and also from hunting for meat (in Brazil). The limbs of Linnaeus’s Sloth are more even sized than those of three-toed varieties, and they tend to be bigger in general.
The average Linnaeus’s Sloth will reach around 46-86 cm in size, and a weight of 4-8.5 kg. They tend to live on average, for around 20-25 years in the wild. The wide range of life expectancy can depend on habitat and population density – the availability of sexual partners and predation.
These sloth can live much longer in captivity, often reaching 40 years of age.
The oldest sloth ever recorded is a Linnaeus’s Sloth called Jan, who reached the age of 52 on 30th April 2022. The record before that also belonged to a Linnaeus’s Sloth called Paula, who lived to an age of 51.
Hoffmann’s Two-toed Sloth
Hoffmann’s Two-Toed Sloth live in two separate areas north and south of the Andes mountains in Central America and South America.
North of the Andes they can be found in Honduras in Central America, spreading to Ecuador in the South. South of the Andes they are found in Peru, Bolivia and Brazil.
Hoffmann’s Sloth has potential to be the heaviest of the species, with adult weight varying between 2.1-9 kg. The range between 54-72 cm and have a very short tail. They are very similar in appearance to the Linnaeus’s Sloth.
Unlike other species of Sloth, there are 5 subspecies of the Hoffmann’s Sloth that are recognised, each with their own distinct habitat range.
Hoffmann’s Sloth reach sexual maturity between the ages of 2 and 4 years old. They have a life expectancy, ranging around 15-20 years in the wild on average, and have been known to reach over 40 in captivity.
What can impact the life of a Sloth?
Tropical rainforests in South America have experienced massive rates of deforestation. Sloths rely on this environment to exist in the wild. It is living in the trees that allows them to survive in their habitat. When they do come to ground to deficate, this is when they are at their most vulnerable to predators. They only need to do this once every week or so, but when they do, they are at great risk. Sadly, due to habitat loss they are coming to ground more often.
Other human influences can also impact the life of a Sloth. One cause of death that is caused by human activity, is from overhead power lines. Sloth have been know to grab hold of these unaware of the dangers. Illegal trafficking is also a risk.
If their environment is stable, they are very good at surviving and maintaining their numbers. But their environment is being put under pressure more and more each day.
Lifecycle of a Sloth
The gestation period of a sloth varies. Three-toed species like the Maned or Brown Throated sloth generally have a gestation period of around 6 months. Two-toed sloths such as Hoffmann’s Two-toed Sloth have a gestation period of six months to a year, depending on the species.
Three-toed sloths do not have a mating season. They breed year round, though data for some species, particularly the Maned Sloth, show that the majority of births occur between the months of February and April. Once born, the young will cling to their mothers belly for around 9 months, after which they are weaned off and the mothers move away.
Some two-toed sloths carry their babies for longer. The Linnaeus species have a similar gestation period to the three-toed species. But the Hoffmann species have a gestation period of around 11 and a half months. Mothers will continue to carry their babies for 6 to 9 months after birth, buy they are typically weaned after around a month.
Two-toed sloth reach sexual maturity around the age of 3 years (female) to 5 years (male). However, they become independent from around 9 months to a year after birth. At this time mothers will move out into new territory, leaving the young to get on with it on their own.
Adult sloth across all species, are very solitary creatures. They mark their territory with anal scent glands and by creating dung middens – where they return to the same spot to defecate, creating a large pile of dung. Males don’t like to share territory with competitors and are attracted to females when ready to mate, through their screams echoing around the tree tops. Females sometimes congregate together.
Most species of Sloth are nocturnal, they are most active at night and sleep all day. They sleep about 15 to 18 hours each day, hanging upside down.
While these animals are restricted to Central and South America, they are successful in the habitat in which they live. There are many predators such as the jaguar, ocelot, snakes (particularly the anaconda) and the harpy eagle. However, it is thought that sloth move so slowly that they most often go unnoticed by these predators, who’s attention is caught by more active and noticeable prey.
The sloth plays an important part in it’s ecosystem, particularly for the trees. They help not only by eating the leaves of the trees, but in fertilizing them with their dung. Some species, such as the pale throated variety also co-exist with a type of algae that exists in their fur, or insects such as the sloth moth. They are considered to play an integral part in the ecosystem of the South American tropical rainforests.