MONGOOSE LEMUR

Eulemur mongoz

Geographic Distribution and Habitat
The mongoose lemur is endemic to the northwestern forests of the island of Madagascar. Much of their habitat consists of dry deciduous forests, fragmented forests, and scrublands. They can also thrive in northwestern Madagascar’s secondary forests. Most plants and animals found in Madagascar are unique to the island, mainly because the island was detached from Africa millions of years ago and is isolated from any other continent.

Mongoose lemurs can also be found on Moheli, Anjouan, and Grande Comoro islands in the Comoros Archipelago, where they were most likely introduced by humans hundreds, if not thousands, of years ago. On these islands, the forests are much more humid than those of northwest Madagascar. The mongoose lemur is one of only two lemur species found living wild outside of Madagascar.

Mongoose lemur range, IUCN 2020

Size, Weight, and Lifespan
Although mongoose lemurs do not have much in common with the carnivore for which they are named (the mongoose), they do share their small body size. Their head-to-body length averages 13.7 inches (35 cm) long and their tail length averages 19 inches (48.3 cm). They weigh between 4.4 and 6.6 pounds (2–3 kg).

They can live up to 30 years in the wild and even longer in captivity.

Appearance
Mongoose lemurs are sexually dichromatic in their pelage, meaning fur color varies by gender. Males have a gray body and gray fur on the top of their heads. Right under their shoulders, the fur is tinted a brownish red color that flows down to their hind limbs. They have white beards when they are born that turn red as they grow older. The tail tips of male mongoose lemurs is darker than those of females. In contrast, females are lighter gray. They have creamy white fur on the sides of their body, on the sides of the face, and under the chin.

Like other lemurs, mongoose lemurs have binocular vision, which allows them to focus on an object with both eyes creating a single image. This type of vision is necessary for depth perception and is beneficial to many primates, especially for catching prey, grasping onto substrates, and locomotion.

In addition, mongoose lemurs are superior sniffers. Like all lemurs and most other prosimians (excluding tarsiers), mongoose lemurs are strepsirrhines or wet-nosed primates. Their wet nose feature is attributed to the presence of the rhinarium, the hairless skin area that surrounds the nostrils, much like you’d see in cats and dogs. The moist rhinarium enhances olfactory (smell) perception. Scent molecules in their nostrils allow them to smell far more than we can even imagine.

What Does It Mean?

Cathemeral:
Irregularly active during night or day, dawn or dusk, depending on environmental circumstances.

Gestation Period:

The time of pregnancy from conception until birth. 

Quadrupedal:

Using four limbs to move about. This word comes from the Latin meaning “four feet.”

Visit the Glossary for more definitions

Diet
Frugivorous and folivorous, mongoose lemurs consume fruit, leaves, flowers, nectar, and pollen. Their diet is highly dependent on the season and food availability. For example, most of their diet consists of fruit, but during the dry season, when less fruit is available, they eat more foliage. 

Behavior and Lifestyle
Mongoose lemurs are cathemeral, meaning they may be active during parts of the day or night throughout the year, depending on the season. In the dry season (May–November) they tend to be more nocturnal. The shift to increased night activity in the dry, hot season helps lemurs conserve energy by being most active during the coolest parts of the day. Also, during this season, there is the least amount of forest cover, so being active during the night can help avoid predators. Mongoose lemurs switch to more diurnal activities during the colder, wet months.

Adult mongoose lemurs use two main forms of locomotion. They walk quadrupedally when traveling through branches or on the ground. Usually, they only walk on the ground to travel from tree to tree or bush to bush, as they spend most of their time in the trees. When mongoose lemurs want to move quickly between trees, they use their powerful hind limbs to leap from branch to branch or tree to tree. Infants hold tightly onto the mother while they travel. As infants grow larger, they begin to travel quadrupedally and eventually build up the strength to leap.

Fun Facts

Male mongoose lemurs mark their territory by rubbing the scent glands on top of their head on surfaces. They often develop bald spots because of this.

All lemurs are captivating animals and play a role in attracting tourists to Madagascar.

Daily Life and Group Dynamics
In northwestern Madagascar, mongoose lemurs live in small groups of 3 to 4 individuals: an adult male, an adult female, and their offspring. Matured offspring leave their natal group between 2 and 3.5 years old. Females are typically dominant, giving them the primary choice over food and mates.

Home ranges are small and tend to overlap each other. Intergroup encounters are rare and, although mongoose lemurs are relatively peaceful, sometimes these encounters can cause agitation between groups.

Larger groups of mongoose lemurs are found on the Comoro Islands. Group sizes can be influenced by food availability and climatic changes.

Communication
A well-developed sense of smell allows mongoose lemurs to communicate through scent-marking. They rub surfaces with scent glands on their head (mainly males), chest, and wrists to mark their territory. The scent-markings left behind are filled with useful information for other lemurs. It’s often used for mating opportunities and other lemurs can tell if the scent belongs to a female in estrus or if an individual is healthy. Lemurs can also determine how long ago the scent was left or who has left it (young or old, male or female).

Additionally, mongoose lemurs groom one another to form and maintain tighter social bonds. Using their toothcomb, compromised of six teeth on their lower jaw, they comb through, clean, and remove any dirt or parasites from one another’s fur.

Mongoose lemurs have many context-specific vocalizations that are emitted throughout the day. Two of the main calls used are alarm calls and territorial calls. If an opposing group is nearby, a “croui-croui” call is released to advertise that this is their territory. This call is also used to regroup individuals at sunset. When they come face to face with members of an opposing group or another predator, mongoose lemurs emit a “cree” call that sounds similar to a loud screech. Additional vocalizations include grunts, clicks, snorts, chatters, and hoots.

Visual cues such as specific facial expressions and body postures are also used in communicating. Mongoose lemurs often use vocalizations with closed mouths (or nasal calls). However, long grunt calls are made with open mouths, accompanied by tails wagging. Crouched postures are used with alarm calls and standing postures (mainly on all fours) are sometimes used with territorial calls.

Reproduction and Family
In Madagascar, mongoose lemurs form monogamous pair-bonds; however, it is possible that they are polygynous in the Comoros Islands where there are larger group sizes and where there may be a larger population. Mating is seasonal and females experience estrus for about one month between April and June. They give birth to one offspring per year typically after a gestation period of 128 days. Infants are born between September and October.  

Female mongoose lemurs are exceptional mothers and care-givers. They nurse their young until they are about 5–6 months old. They also groom, play, socialize, and carry the young on their bellies. As a youngster gets older and stronger, he or she starts to ride on the mother’s back. A tight grip is necessary for survival from predators on the forest floor and even hawks that are watching from the sky and forest canopy.

At about 1.5–2 months of age, infants begin to take their first tentative steps. Once they reach full maturity between 2 and 3.5 years old, they are encouraged to leave their natal groups.

Photo credit: robglinka/Flickr/Creative Commons

Ecological Role
​Since mongoose lemurs are frugivorous, they help disperse the seeds they eat throughout the forest. When they feed on flowers, they help pollinate some plant species. The pollen gets stuck to their fur, their hands, and even their snout. Mongoose lemurs then carry this pollen with them to another flower, which tends to rub off on the flower as they eat, helping to pollinate the plant.

Conservation Status and Threats
The International Union for Conservation of Nature lists mongoose lemurs as Critically Endangered (IUCN, 2018), appearing on the IUCN’s Red List of Threatened Species. Forests in northwestern Madagascar are severely fragmented and continue to be cleared due to slash and burn agriculture, creating pastures for cattle, and charcoal production. Unfortunately, this has led to a large decrease in mongoose lemur populations and has even completely wiped out some groups.

Mongoose lemurs are often trapped and hunted. In some areas they are trapped for the illegal pet trade and  are considered to be crop pests, especially in the Comoros Islands. There has been a large influx of people onto the Comoros Islands who do not adhere to local customs, which have previously provided mongoose lemurs a greater degree of protection.

Conservation Efforts
Mongoose lemurs are also listed on Appendix I of the Convention on International Trade in Endangered Species (CITES) and are protected by law on the Comoros Islands. Although the legal protection of mongoose lemurs tends to be ignored, the lemurs are known to occur in the protected areas of Ankarafantsika National Park (Ampijoroa), the Mahavavy-Kinkony Wetland Complex, and Antrema at Katsepy. More mongoose lemur populations are being protected through community-based conservation of the Anaboazo, Ambahivahy, and Mangidirano forests and in Ankirihitra and Mariarano forests of Madagascar.

Attention is needed toward the enforcement of the last of the remaining viable habitat of mongoose lemurs, which is quickly being diminished. Further population monitoring, site management, and stricter laws may allow for this species and their habitat to eventually bounce back in some areas.

References:

  • https://www.iucnredlist.org/species/8202/115561431
  • https://www.saczoo.org/wp-content/uploads/2016/11/mongoose_lemur2.pdf
  • https://www.lemurreserve.org/lemurs/mongoose-lemur/
  • https://resourcelibrary.clemetzoo.com/Animal/85
  • https://animaldiversity.org/accounts/Eulemur_mongoz/
  • https://lemur.duke.edu/discover/meet-the-lemurs/mongoose-lemur/
  • Tattersal I., Sussman R.W. 1975. Observation on the Ecology ad Behavior of the Mongoose Lemur Lemur Mongoz Mongoz Linnaeus (Primates, Lemuriformes), at Ampijoroa, Madagascar.  Anthropological Papers of the Museum of Natural Hisotry New York. 52(4): 195-216.
  • Nadhurou B., Gamba M., Andriaholinirina N.V., Ouledi A., Giacoma C. 2015. The vocal communication of the mongoose lemur (Eulemur mongoz):phonation mechanisms, acoustic features and quantitative analysis. Ethology Ecology & Evolution. 3-22.​

Written by Tara Covert, May 2021