Small-Toothed Sportive Lemur, Lepilemur microdon
SMALL-TOOTHED SPORTIVE LEMUR
Lepilemur microdon
Geographic Distribution and Habitat
The small-toothed sportive lemur (Lepilemur microdon), also known as the light-necked sportive lemur and the microdon sportive lemur, is native to the dense rainforests of Madagascar. They are typically found in southeastern Madagascar and range forests from Ranomafana National Park to Andringitra National Park. The land that the species occupies is only 99.42 square miles (160km) and extremely fragmented, partially due to human destruction of the environment but largely due to competing niches with Eastern woolly lemurs (avahi laniger). The forests are categorized as subtropical and tropical moist lowlands.
Size, Weight, and Lifespan
The small-toothed sportive lemur is one of the smallest folivorous (leaf-eating) primates but is larger than other sportive lemurs. Their weight ranges from 2.0 to 2.6 pounds (0.9 to 1.2 kg) with a head and body length of 11 to 13 inches (27 to 32 cm). Their tails add 11 to 12 inches (27 to 30 cm).
Lifespan is not well recorded due to the lack of research on these lemurs. However, generally their lifespan ranges from 8 to 10 years. In captivity, their lifespan can reach up to 15.
Appearance
The coat of the small-toothed sportive lemur is primarily thick and reddish-brown with a dark stripe traveling along the midline. On the belly, face, and sides of the neck, the fur is a lighter beige-gray and with a slight yellow tint in some monkeys. The arms up to the shoulders are a darker chestnut brown and the tail darkens as it reaches the tip. Their very large eyes are forward-facing and a notable yellow-orange.
On their hands and feet are very large digit pads that allow for more adhesion when clinging and jumping vertically from trees.
Small-toothed sportive lemurs lack permanent incisors and they also have smaller molars compared to other sportive lemur species, hence the name “small-toothed” sportive lemur and “microdon”. “Micro” meaning small and “don” referring to dontics, or teeth. They very closely resemble the weasel sportive lemur (L. mustelinus) and are almost indistinguishable by their appearance except for by their molars.
Diet
Like many of the sportive lemur species, the small-toothed sportive lemur has a low resting metabolic rate, is folivorous, and cannot digest cellulose. Since their low metabolic rate allows them to survive off of fewer calories for their bodily maintenance, they are able to comfortably live off of leaves but will consume flowers and fruits when available. Leaves are made of cellulose and since the small-toothed sportive lemur cannot digest it, the monkey relies on bacteria to help break it down. Small-toothed lemurs have a large caecum, a small pouch found in between the large and small intestine, that holds the essential bacteria necessary for digestion. Most nutrients are broken down and absorbed at this stage of digestion. To additionally ensure that all of the nutrients are consumed, small-toothed lemurs are caecophages. They consume their own feces to re-digest the leaves they had defecated, allowing for complete absorption of all the nutrients in the leaf.
Behavior and Lifestyle
Small-toothed sportive lemurs are nocturnal, meaning they sleep during the day and are active at night. During the day, small-toothed sportive lemurs sleep in tree cavities or tangles of vines and other vegetation. They are very picky with the types of trees they decide to inhabit. The monkeys choose large trees with a diameter and breast height no smaller than 2 feet (63 cm).
Since they are arboreal (living in trees), the small-toothed sportive lemurs have hands and feet equipped with large digital pads that allow them to jump from tree to tree. Their name “sportive” demarcates their physical ability to jump vertically from tree trunk to tree trunk.
Current studies recognize over 25 different sportive lemur species!
Small-toothed sportive lemurs look nearly identical to the weasel sportive lemur (L. mustelinus) but their geological habitats allow scientists to distinguish them from one another.
Small-toothed sportive lemurs are polygynous and solitary lemurs. They sleep in tree cavities or vine tangles with groups of 1 to 3 individuals. Males typically sleep alone but females sleep with their young offspring in addition to the occasional male.
Their home ranges are small and are explicitly outlined by scent-marking and male crow-like calls. Males also fight for their territory and will have small scuffles in the evening. The rest of their active night is spent in guard of their home, resting, searching for food, and letting leaves digest. Males will travel roughly an average distance of 1045 feet (320 m) but are considered to have low activity rates overall.
Due to the lack of research on these lemurs, little is known about their overall activity rate. However, the consensus is that they are lower in activity than other sportive lemurs and spend some of the night foraging and minimally socially interacting with other small-toothed sportive lemurs.
Small-toothed sportive lemurs communicate notably less than other sportive lemur species that live in drier forest environments. Males have a vocal call that sounds similar to a crow in order to lay the boundaries of their territory. They will also use scent-marking to establish those boundaries as well.
Since the small-toothed sportive lemur is polygynous, males will mate with many females. Females typically have offspring once per year with a gestational period of 4-5 months. The birthing season starts in September and generally lasts until December. The age of maturity for both males and females falls around 18 months and most young are weaned by 4 months. Young monkeys may stay with the mother up until a year of age, sleeping in the same sleeping cavity and being provided for by the mother. Mothers will leave their young inside the sleeping cavity during active hours at night to find food.
With a diet that primarily consists of leaves, they participate in pruning the foliage of the forest. When fruits are available and consumed, small-toothed sportive lemurs will spread seeds into their environment through their feces.
They are predated by large forest boas, large birds, and fossas.
The small-toothed sportive lemur is classified as Endangered by the International Union for Conservation of Nature (IUCN, 2020), appearing on the IUCN Red List of Threatened Species.
Previously, due to their physical similarities with other sportive lemur species and confusion with taxonomy, they were labeled as Data Deficient when assessed by the IUCN Red List in 2008. Since then, with more data and more research, the small-toothed sportive lemur’s conservation status has been more appropriately assessed.
The main threat to the small-toothed sportive lemur is slash-and-burn agriculture. This practice severely disrupts their natural habitat and causes a myriad of environmental issues aside from the direct effect of habitat destruction.
They have also been found to be hunted with spears and by chopping down trees with nest holes.
Small-toothed sportive lemurs are also predated upon by large boas, diurnal birds of prey, for example, the Henst’s goshawk, and other large forest predators like the fossa.
The small-toothed sportive lemur is listed in Appendix I of the Convention on International Trade in Endangered Species (CITES), an international agreement between governments whose goal is to ensure that international trade in specimens of wild animals and plants does not threaten their survival. They are also protected in Ranomafana National Park and Andringitra National Park but with extensive confusion on the identity of the small-toothed sportive lemur, scientists are unsure how much or where in the park they occupy. More research is needed to understand the true habitats and locations of these monkeys.
- Influences on the Distribution of Lepilemur microdon in the Ranomafana National Park, Madagascar by Leila M. Porter (Folia Primatol 1998;69:172–176)
- IUCN Redlist
- Encyclopedia of Life (eol.org)
- Global Biodiversity Information Facility (gbif.org)
- Primate Adaptation and Evolution (3rd Edition) by John G. Fleagle (Chapter 4- The Prosimians: Lemurs, Lorises, Galagos and Tarsiers)
Written by Nami Kaneko, March 2025