RED-FRONTED BROWN LEMUR

Eulemur rufifrons

Geographic Distribution and Habitat
The red-fronted brown lemur, sometimes called simply the red-fronted lemur, is found in dry, tropical forests in western Madagascar and moist lowland and montane forest in eastern Madagascar. In western Madagascar, it is found between the Tsiribihina River in the north and the Fiherenana River in the south. In eastern Madagascar, it occupies a narrow strip between the Mangoro and Onive rivers and the Andringitra Massif. Its range encompasses five national parks and several reserves. In the west, where population density is high, the home ranges of each group tend to be small, whereas, in the east, population densities tend to be lower and home ranges can be as large as 247 acres (100 ha).

Red-fronted brown lemur geographic range, IUCN 2020

Size, Weight, and Lifespan
The red-fronted brown lemur is relatively small, with adults weighing approximately 4.9 lbs (2.2kg). Head and body length is around 14.9 in (37.8 cm), with tails adding an extra 19.7 in (50 cm).

The lifespan of this species is estimated to be around 15 years in the wild, although individuals in captivity sometimes live for over 30 years.

Appearance
Red-fronted brown lemurs are sexually dichromatic, meaning that males and females have different coloring. Males have a grayish-brown body with a distinctive cream colored collar and cheeks. They have an orange forehead and a thick black stripe down the center of their face. 

Females have a reddish-brown body and also have a black stripe down the center of their face, surrounded by white cheeks and a white forehead. They have a dark gray patch at the top of their heads and dark tails. Both sexes have dark noses and yellow-amber eyes.

At birth, infants all have adult male coloring, but females begin to develop their sex-specific coloring at around 3–4 months.

What Does It Mean?

Eviction:
When an animal is forced to leave the group by other group members, usually to reduce intra-group competition. 

Polygamous: 
Having more than one mate.

Sexual dichromatism:
When male and female animals of the same species display different colorations.

Slash and burn agriculture:
A method of unsustainable farming where farmers clear land by cutting and burning flora in order to create an empty field—a “swidden”—for cultivation. Such practices are detrimental to local ecosystems.

Visit the Glossary for more definitions

Diet
The diet of red-fronted brown lemurs can vary across habitats but generally includes fruits, leaves, buds, and flowers, in addition to some invertebrates. While they prefer fruits and flowers when they are available, in the dry season the bulk of their diet can consist of leaves. 

Individuals of this species have been shown to innovate new foraging behaviors, including members of one group who feed on social spider nests. Other groups whose home-range also contained these nests didn’t show this feeding behavior, indicating that these lemurs can differ in their ability (or motivation) to innovate, or to learn from one another.

Behavior and Lifestyle
Red-fronted brown lemurs can be active during the day and night. They exhibit a high level of behavioral flexibility and their lifestyle can vary depending on where they live. Groups in some areas spend all of their time in the trees, whereas groups in other areas sometimes forage and travel on the ground, despite the presence of ground predators. When in the trees, these lemurs generally remain fairly high in the canopy, at an average of around 50 feet (15 meters) off the ground. When they sleep, they often huddle together, wrapping their tails around themselves. ​

Daily Life and Group Dynamics 
Red-fronted brown lemurs live in groups of between 5 and 15 individuals, including multiple adult males and females. Compared to other primate species, they don’t have a strong dominance hierarchy, and they exhibit high levels of social tolerance with low levels of aggression. However, one adult of each sex may be particularly powerful within the group.

Males disperse upon reaching sexual maturity, at around four years of age. They will join other groups and probably migrate several more times throughout their lives. Interestingly, females can also disperse, but not voluntarily. This species displays female eviction, where females are forced out of their birth group by other females. This seems to depend on the size of the group—when the group reaches more than 10 individuals, the probability of a female or females being forced from the group increases. It is likely that this “forced eviction” reduces competition for resources within the group. Scientists do not yet know how often or easily evicted females are able to join other groups.

Fun Facts

Despite their color-specific name, these lemurs are sexually dichromatic, meaning the females show different coloring to the males.

These lemurs show forced female eviction, where females are sometimes forced to leave the group when the group grows too large.

Unfortunately, these are the most commonly hunted lemurs in the Kianjavato region of Madagascar.

Red-front brown lemurs show a high level of behavioral flexibility; populations in the east exhibit differences in habitat use and group dynamics than populations in the west of Madagascar.

Communication
This species exhibits a range of vocalizations, including loud and close calls. Close calls, also known as grunts, play a role in group coordination; individuals may grunt to indicate willingness to move, or to recruit others to move. Interestingly, they don’t seem to distinguish calls of their own species from those of similar brown lemur species.

Olfaction also plays a large role in this species’ communication—these lemurs will rub secretions from olfactory glands onto a substrate, like a branch, as a signal to others. In particular, females from the taxa Eulemur seem to exhibit more scent marking than males.

Reproduction and Family
On average, females first give birth between the ages of 3 and 4 years. While females can reproduce annually, in general, not every female in the group will reproduce each year. Instead, they compete with other females in their groups to reproduce. In the absence of a clear hierarchy, body size and age seem to influence which females will be successful at reproducing each year. 

Their mating system is polygamous, meaning that many males may mate with many females. However, the most powerful male fathers more infants than other males. When females do give birth, they will usually have just one infant, although twins do occur. This infant will cling to its mother as she moves around the forest, before beginning to venture further from her as to explore his or her new world. 

Photo credit: JialiangGao www.peace-on-earth.orgCreative Commons

Ecological Role
Red-fronted brown lemurs eat both fruits and leaves, and therefore likely play roles in both seed dispersal, as well as the pruning of plants to encourage new leaf growth. The seeds that they ingest can be spread throughout their home range when they defecate, allowing the plants to spread to new areas.

Conservation Status and Threats
The red-fronted brown lemur is classified as Vulnerable by the International Union for Conservation of Nature (IUCN, 2020) and their population is in decline. They are hunted both for bushmeat and for the pet trade. This species is one of the most commonly hunted lemurs in the Kianjavato region, which is likely a leading cause of their population decline. Other major threats to this species are habitat loss and degradation and fragmentation because of logging and livestock farming and ranching. 

In addition to humans, the main predator of these lemurs is the Malagasy carnivore, the fossa.

Conservation Efforts
This species is listed on Appendix I of the Convention on International Trade in Endangered Species (CITES). It is known to occur in a number of protected areas throughout its range, providing it with some protection. However, more conservation actions will be needed to stop this species becoming endangered like so many other lemurs.

References:

  • ​de Winter, I. I., Gollner, A., & Akom, E. (2013). Diet overlap of Propithecus verreauxi and Eulemur rufifrons during the late dry season in Kirindy Forest. Lemur news17, 18-21.
  • Del Barco-Trillo, J., Sacha, C. R., Dubay, G. R., & Drea, C. M. (2012). Eulemur, me lemur: the evolution of scent-signal complexity in a primate clade. Philosophical Transactions of the Royal Society B: Biological Sciences367(1597), 1909-1922.
  • Johnson, S., Narváez-Torres, P.R., Holmes, S.M., Wyman, T.M., Louis, E.E. & Wright, P. 2020. Eulemur rufifronsThe IUCN Red List of Threatened Species 2020: e.T136269A115581600.
  • Kappeler, P. M., & Fichtel, C. (2012). Female reproductive competition in Eulemur rufifrons: eviction and reproductive restraint in a plurally breeding Malagasy primate. Molecular Ecology21(3), 685-698.
  • Mittermeier, RA, Ganzhorn JU, Konstant WR, Konstant WR, Glander K, Tattersall I, Groves CP, Rylands AB, Hapke A, Ratsimbazafy J, Mayor MI, Louis EE Jr, Rumpler Y, Schwitzer C, Rasoloarison RM. 2008Journal Article.Lemur diversity in Madagascar. International Journal of Primatology.
  • Rafidimanana, D. V., Holmes, S. M., Johnson, S. E., Louis Jr, E. E., & Rakouth, B. (2017). Relationship between vegetation characteristics and the presence of lemurs: Varecia variegata, Eulemur rubriventer and Eulemur rufifrons in Kianjavato forest fragments. Lemur News20, 15-19.
  • Schnoell, A. V., & Fichtel, C. (2013). A novel feeding behaviour in wild redfronted lemurs (Eulemur rufifrons): depletion of spider nests. Primates54(4), 371-375.
  • Sperber, A. L. (2019). Group Coordination Processes and Determinants of Leadership in Red-fronted Lemurs (Eulemur rufifrons) (Doctoral dissertation, Georg-August-Universität Gottingen).
  • Alltheworldsprimates.org

Written by Jennifer Botting, PhD, March 2021