Black Lemur
Eulemur macaco
Black lemurs are found in northwestern Madagascar, near the Mahavavy River in the north and the Andranomalaza River in the southern part of the region. There are other populations on the islands of Nosy Be and Nosy Komba, and in the coastal forests northeast of Ambanja.
Their main habitats are wet evergreen, dry deciduous, and riverine forests. Black lemurs are quite adaptable and thrive in a wide variety of habitats including primary forests, secondary forests, forest-agricultural mosaics, and timber plantations.
Black lemur geographic range. Map: IUCN, 2020
Black lemurs measure approximately 11.8–19.7 in (30–50 cm) from head to rump. Their tails measures an additional 15.8–23.6 in (40–60 cm). Their weight ranges from 3.3 to 6.6 lb (1.5–3 kg). In the wild, black lemurs average body mass is 4 lb (1.8 kg). In captivity, their body mass averages slightly more at 5.5 lb (2.5 kg).
Lifespan is not well documented; however, based on other similar lemur species, it is anticipated that their lifespan is between 15 and 25 years. The longest known lifespan of a captive black lemur is 36.2 years.
Medium-sized lemurs, black lemurs are sexually dichromatic; that is, males and females have different coloring. Males have a jet-black or dark chocolate pelage over their entire body, with black ear tufts. Females have gray-brown coloration across their back and sides, with a white-brown stomach, a gray face (usually), and white ear tufts.
Males and females are both born the same gray-brown color; this keeps the babies camouflaged as they cling to their mothers' coats. Males turn black at 5–6 weeks of age.
The black lemur (Eulemur macaco) is distinguishable from the closely related blue-eyed black lemur (Eulemur flavifrons) by the latter's brown eyes and ear tufts, and the females' orange coloration.
Male black lemur. Photo credit: Charles J Sharp/Creative Commons
Female black lemur. Photo credit: Charles J Sharp/Creative Commons
Mainly frugivorous, fruit makes up about 73% of their diet. Other foods include flowers, nectar, leaves, bark, nuts, and ants. During the dry season, black lemurs largely consume coffee, papayas, palms, cashews, and plums. In the wet season, papayas, mangos, palm fruits, and flowers make up most of their diet.
Black lemurs are primarily arboreal primates and travel using quadrupedal and leaping locomotion. When they descend to the ground (typically for food), they travel on all fours with bouts of bipedal leaping. Both distance and speed of travel are reduced during the dry seasons, when resources are much more scarce.
​Black lemurs are, interesting, neither solely diurnal nor nocturnal. They are cathemeral primates, that is, they are active at any time of the day or night depending on the circumstances, such as food availability, predatory threats, and ambient temperatures.
Nocturnal activity is more prevalent during nights when the moon is brightest. It is hypothesized that since lemurs' eyes lack a tapetum lucidum, which is the structure in the eye that enhances night vision, they may have a difficult time seeing when the moon is less bright. The highest activity rates occurs between 6 and 8 a.m. and 4 and 6 p.m.
​In the Eulemur genus, cathemerality activity can occur in three different modes: 1) it can vary seasonally, with nocturnal behavior dominating one season and diurnal dominating the other; 2) it can shift seasonally with diurnal activity in the winter to 24-hour activity in the summer; or 3) it can be 24-hour activity throughout the year with no link to seasonal variation.
Agonistic:
Of, relating to, or being aggressive or defensive social interaction (such as fighting, fleeing, or submitting) between individuals usually of the same species.
Anogenital:
Relating to the anus and genital region.
Deciduous Forest:
Forests that change seasonally. The word deciduous means to fall off at maturity. The opposite of deciduous is evergreen.
Diurnal:
Active during daylight hours.
Frugivorous:
Having a diet that consists of fruits.
Multi-male multi-female group/unit (MMU):
A social group consisting of multiple adult males and multiple adult females.
Perianal gland or sac:
Small glands near the anus in many mammals.
Polygynandry:
A mating system in which both males and females have multiple mating partners during a breeding season.
Quadrupedal:
Using four limbs to move about. This word comes from the Latin meaning "four feet."
​Riverine forest:
A forest that is located nearby or adjacent to a river.
Viverrids:
A group of 35 species including the genets, binturong, civets, and linsangs.
Daily Life and Group Dynamics
Black lemurs are very sociable prosimians that live in multi-male/multi-female groups of 4 to 15 individuals. Females are dominant and family bonds are very strong. Group size and home range depend on the composition of the forest and the amount of resources. The composition of a group, such as size, age of individuals, and difference between group members, may vary. This is mainly due to dispersal of juvenile males and females, and males transferring between groups during mating season. Females may transfer to another group when a group exceeds the maximum size.
Generally speaking, home ranges extend from .01 to .02 square miles (3.5–7 ha). It is not unusual for groups' home ranges to overlap. When groups encounter one another, they display territoriality by leaping back and forth and tail swishing. Physical aggression is rare.
This species has been observed antagonizing giant toxic millipedes. They gently bite the millipede until it secretes toxins, but they do not injure or kill it; then they rub the toxins on their coat. The toxins in the millipede secretions contain insecticidal properties that are beneficial to lemurs. The toxins also leave the lemur with a "high" sensation.
Like most lemur species, black lemurs communicate using scent-markings. They release strong secretions from their perianal glands that are used to scent-mark their surroundings, which outlines their territory. In addition, males mark with the scent glands on their hands and at the tops of their heads. These scent-markings convey important information about specific individuals (almost like a "calling-card").
Black lemurs also use vocalizations like grunting, purring, screeching, and shrilling. A cohesion call is emitted to keep track of other group members, while grunting is used when one individual identifies another. Purring by infants indicates contentment (mostly while being groomed). Other vocalizations like screeches or shrills are used as an alarm call to warn off predators.
​Black lemurs have a number of predators including humans, raptors, and viverrids such as civets or genets. When a predator is sensed, alarm calls are made including shrieks and grunts. Other behaviors that are displayed include tail wagging, staring, and mobbing. "Mobbing" behavior is when a group collectively chases away a predator. This tactic is mainly employed to protect against large snakes such as boa constrictors and harrier hawks. Black lemurs mostly rely on their group and alarm call warnings for protection.
Lemurs have flat fingernails like those of humans.
Lemur in Latin means "ghost," which suits black lemurs perfectly since they are tree dwellers and are often invisible high in the dense trees.
Black lemurs are often spotted foraging at night to drink nectar from Parkia tree flowers.
When black lemurs (E. macaco) mate with blue-eyed black lemurs (Eulemur flavifrons) their offspring have brown eyes.
Black lemurs are found on an island called Nosy Komba, where they are considered sacred by the indigenous population.
Reproduction and Family​
The black lemur is a polygynandrous species, meaning that both males and females have multiple mating partners. Scent-marking plays a large role in the mating ritual. Males scent-mark females by clasping them and ano-genital grooming. Males may also display "roaming mating behavior" in breeding season by leaving their social group and following females from other groups. Female choice plays a significant role in mating. They can choose to mate with dominant, subordinate, or roaming males, and they can opt to reject males, sometimes using aggression.
Upon maturity, males emigrate into other groups while females remain with their natal group. Mature males increase their between-group interactions during mating season (between April and May), but in birthing season (August to November) there is less interaction between groups. ​Altercations are infrequent, but can escalate during mating season.
​During mating season, black lemurs spend less time eating and more time seeking mates. Males may become more aggressive toward other males. After conflicts, the lemurs tend to disperse.
Generally, females give birth to one offspring per year, but twins are not unusual. When an infant is born, he stays in constant contact with his mother for the first months, nursing most of the time. Adult males do not go near the mother or infant until the newborn is several days old. Mothers display increased agonistic interactions over fruit sources during lactation after childbirth.
Infants cling to their mothers' bellies while they travel through the forest. Often times, when the mother is not moving, she covers the infant completely, almost forming a protective barrier around the infant. At three weeks the infant begins to ride on his mother's back. At between 40 and 45 days of age, the infant slowly starts to separate from his mother, although they can continue to nurse for up to 6 months.
Photo credit:Visiting Madagascar/Creative Commons
Due to their large intake of fruits, black lemurs play a very important role in seed dispersal throughout the forest. They are also known to act as pollinators for the flowers that they drink nectar from—specifically Parkia tree flowers.
The International Union for the Conservation of Nature lists black lemurs as Endangered (IUCN, 2018), appearing on the IUCN Red List of Threatened Species. Their populations are declining due primarily to habitat fragmentation and loss; bushmeat hunting. The range of the species is severely fragmented and remaining areas of forest are under anthropogenic pressure. Black lemurs are subjected to severe ecosystem stressors such as habitat loss due to illegal exploitation of timber, firewood, and charcoal production. Slash and burn agriculture is also a persistent threat in northwestern Madagascar, where black lemurs are killed for raiding crops in some areas. They are also a source of bushmeat. In addition, there is illegal (domestic) trade in live black lemurs for the pet trade.
Black lemurs are listed as an Appendix I species by the Convention on International Trade in Endangered Species (CITES). They are found in two strict nature reserves, Lokobe and Tsaratanana, and one national park, Sahamalaza-Iles Radama, as well as in Manongarivo Special Reserve. They are present on the island of Nosy Komba, where local people consider them to be sacred. They also serve as a large tourist attraction on Nost Tanikely.
More area and site protection is needed for this species as well as land, water, and habitat protection and management. Research is needed for monitoring and conservation techniques.
​References:​
https://animaldiversity.org/accounts/Eulemur_macaco/
https://www.iucnredlist.org/species/8212/16117639#habitat-ecology
https://lemur.duke.edu/discover/meet-the-lemurs/common-black-lemur/
https://www.lemurworld.com/black-lemur/
https://www.inaturalist.org/taxa/43609-Eulemur-macaco
Colquhoun, I. 1997. A Predictive Socioecological Study of the Black Lemur (Eulemur macaco macaco) in Northwestern Madagascar. Saint Louis, Missouri: Washington University.
Colquhoun, I. 1998. Cathemeral Behavior of Eulemur macaco macaco at Ambato Massif, Madagascar. Folia Primatologica, 69.1: 22-34.
Bayart F., Simmen, B. 2005. Demography, range use, and behavior in black lemurs (Eulemur macaco macaco) at Ampasikely, Northwest Madagascar. American Journal of Primatology. 67(3) 299-312.
Schwitzer N., Kaumanns W., Seitz PC., Schwitzer C. 2007. Cathemeral activity patters of the blue-eyes black lemur Eulemur macacao flavifrons in intact and degraded forest fragments. Endagered Species Research. 3: 239-247.
Written by Tara Covert, May 2019. Conservation status updated July 2020.