BLACK-AND-WHITE RUFFED LEMUR

Varecia variegata

Geographic Distribution and Habitat
The black-and-white ruffed lemur (Varecia variegata) is endemic to the island of Madagascar. It is sparsely distributed throughout the declining eastern tropical rainforests, from the Antainambalana River to the Mananara River. The black-and-white ruffed lemur lives in ten protected areas, but their population size is still declining. In the past thirty years, this species has declined approximately 80%, which is pretty extreme when one considers that these animals evolved independently on Madagascar for 50-60 million years.

Black-and-white ruffed lemur geographic range, IUCN 2020

Size, Weight, and Lifespan
An adult black-and-white ruffed lemur can weigh up to 10 lbs (4.5 kg). They can reach 20 to 22 in (50–55 cm) in body length and an additional 24 to 26 in (61–66 cm) in tail length.

Black-and-white ruffed lemurs are thought to live an average of 19 years in the wild and closer to 25 years in captivity.

Appearance
With many primates, their name draws inspiration from their appearance, and the black-and-white ruffed lemur is no exception. Exactly as it sounds, this lemur has black and white coloration with a fringe of white framing their small, pointed faces. Their hands, feet, tails, and faces are typically an inky black, while a patchwork of white lines the fur on their backs and parts of their legs. And if this species wasn’t visually striking enough, it also has wide, round, and bright yellow eyes.

This species does have numerous color variations—populations in the north of Madagascar appear darker than those in the south. However, the significance and importance of those color variations will never be fully understood due to extreme habitat loss. That being said, a study has concluded that there are no appreciable genetic differences among the different color variants of the black-and-white lemurs, which is important for any potential reintroduction of lemurs into the Betampona Reserve. It would be counterproductive should a different subspecies be inadvertently introduced to the wild population.

What Does It Mean?

Frugivore:
An animal who feeds on fruits.

Endemic:
Native or restricted to a certain area or country.

Arboreal:
Physically adapted to living primarily or exclusively in trees.

Quadrupedal:
Using four limbs to move about. This word comes from the Latin meaning ‘four feet.’ 

Monogamous:
Having only one sexual partner. ​​

Diurnal:
Active during daylight hours.

Visit the Glossary for more definitions

Diet
Black-and-white ruffed lemurs are primarily frugivorous, but will also eat a variety of seeds, leaves, and nectar. 

Behavior and Lifestyle
Black-and-white ruffed lemurs can be found sleeping and feeding in large trees, especially during the warm season when the fruit is plentiful. They prefer the upper half of the forest canopy, perhaps to stay out of sight and reach of predators.

As an arboreal and quadrupedal species, black-and-white ruffed lemurs often travel from branch to branch by running and leaping with surefire accuracy. Due to their tendency to consume fruit, they are quite skilled at hanging from their feet to snag any particularly ripe and tasty-looking fruit that would otherwise be out of reach.

Daily Life and Group Dynamics
The black-and-white ruffed lemur is active most often during early morning and late afternoon. It will travel through the forest canopy and occasionally stop to eat and socialize. Group size can vary—sometimes a group will consist of a monogamous pair and their offspring and other times it will stretch up to 16 individuals, though the larger groups are often comprised of several smaller groups that band together.

Regardless of the group size, each lays claim to a home range, the boundary of which is made clear whenever one group strays too close to the other. There have been reports of aggression between neighboring groups.

Females are dominant and have the strongest social bonds within a group, which means they are often the defenders of their group’s territory. Grooming solidifies social bonds within groups, but unlike other primates, the black-and-white ruffed lemur grooms with their teeth instead of their fingers. The incisors on their lower jaw stick out from their face to form a pretty handy comb.

Fun Facts

Out of nearly 100 different types of lemurs, only two are ruffed, the black-and-white and the red.

With the exception of the aptly named howler monkey, black-and-white ruffed lemurs have the loudest call of all primates.

Their main predator is the fossa, a cat-like, carnivorous mammal that is also endemic to Madagascar.

A group of lemurs is known as a “congress of lemurs.”

Black-and-white ruffed lemurs will often give birth to twins or triplets.

Communication
Black-and-white ruffed lemurs are a highly vocal species; their calls can be heard from up to a half-mile away. In addition to being loud, they also have about twelve vocalizations that range from deep barks to wailing howls. Often, the barking call arises from moments of alarm while the howling signals defense of territory.

Reproduction and Family
Female black-and-white ruffed lemurs breed between May and July and give birth to a litter of infants after a 102-day gestation period. Females can give birth to litters of up to six infants (although two or three is more common) in well-concealed nests high in a tree anywhere from 32 to 65 ft (10–20 m) above the forest floor. Females can nurse up to all six infants simultaneously. Perhaps due to the short gestation period, the infants are often not well developed at birth.

Unlike other lemur species, black-and-white ruffed lemurs will “park” their infants in nests while they go off to forage (the infants are not capable of grasping, so they cannot cling to the bellies or backs of their mother instead). If the infants need to be relocated, the mother will move them one at a time. Generally, they will be moved from the nest after two weeks and will be “parked” in suitable spot in a tree while the mother forages.

Black-and-white ruffed lemur infants develop rapidly, so by three or four weeks they start attempting to follow their mother on their own. Unfortunately, this can lead to accidental falls and related injuries that contribute to an alarmingly high infant mortality rate—65% of black-and-white ruffed lemur infants fail to reach three months of age. However, for those that do live, they become independent at four months of age and reach maturity at 20 months.

Photo credit: SurreyJohn/Creative Commons

Ecological Role
Black-and-white ruffed lemurs have an important role as seed dispersers in Madagascar’s rainforests. As frugivores, they swallow large seeds that are later excreted onto the forest floor. Thus, this lemur is responsible for distributing seeds around the rainforest and contributing to its growth. Therefore, if the ruffed lemurs disappear, trees regeneration could decline as well.

Black-and-white ruffed lemurs are also thought to be the largest pollinators in the world. Through an affinity for nectar, they have developed a fascinating and mutually beneficial relationship with the traveler’s tree (also known as the traveler’s palm). The tree is tall and palm-like, with a single layer of large leaves fanned out on top as its crown. The black-and-white ruffed lemur is capable of pulling open the tough leaves in order to reach a cluster of pale flowers inside. As the lemur drinks the nectar, the plant’s pollen sticks to the lemur’s coat and is dispersed from tree to tree.

Conservation Status and Threats
The International Union for Conservation of Nature Red List of Threatened Species classifies the black-and-white ruffed lemur as Critically Endangered (IUCN, 2019).

As with other lemur species, the black-and-white ruffed lemur is threatened by habitat loss and fragmentation due to human activity. Agricultural techniques like slash-and-burn are especially detrimental, especially in cases where cattle are later allowed to roam free in the resultant clearing and therefore prevent any possible forest re-growth. Mining and logging, even when legal (and often times they are not), also contribute to habitat loss. Natural disasters like tropical cyclones can also be incredibly destructive to black-and-white ruffed lemur habitat (in one case, a cyclone destroyed 80% of the forest canopy, which severely impacted their access to food and nesting sites).

Their large size and diurnal lifestyle also makes them a prime target for hunters; they are among the most heavily hunted of all of Madagascar’s lemurs despite the fact that hunting is illegal (unfortunately, it’s a law that is extensively and shamelessly unenforced). 

Conservation Efforts
While these primates are Critically Endangered in the wild, they actually thrive in captivity. In fact, the astounding success of captive breeding led to an unsupportable spike in captive population, the Species Survival Plan coordinator determined that captive breeding needed better management—individual black-and-white ruffed lemurs that were genetically over-represented in captive populations were no longer bred and a fresh genetic stock was imported from Madagascar, which allowed new breeding pairs to be sent out to various zoos across the country in order to preserve genetic lines and keep the captive populations flourishing.

In the wild, black-and-white ruffed lemur populations are protected in various national parks, though they have disappeared entirely from areas like Analamazaotra Special Reserve and Andringitra National Park. Many other Madagascar rainforests urgently require more protections for this species if they are to survive in the wild. Unfortunately, even though captive breeding is successful, many of those individuals have difficulty adapting to life in the wild, so reintroduction efforts are limited in their success. That being said, there are records of successful integrations of individuals in the wild—one male named Sarph lived for over ten years. He was easily distinguished by his short tail (a result of an injury in his youth) and was documented with a variety of different females during his encouraging stint in the wild.

Of course, even if many other captive black-and-white ruffed lemurs adapted quickly in the wild, reintroduction would be entirely worthless if there are not protected habitats for them to be released into.

​References:

  • https://lemur.duke.edu/discover/meet-the-lemurs/black-white-ruffed-lemur/
  • https://nationalzoo.si.edu/animals/black-and-white-ruffed-lemur
  • https://www.arkive.org/black-and-white-ruffed-lemur/varecia-variegata/
  • https://www.folly-farm.co.uk/zoo/meet-the-zoo-animals/black-and-white-ruffed-lemur/
  • http://pin.primate.wisc.edu/factsheets/entry/ruffed_lemur/cons
  • http://www.madagascarfaunaflora.org/black–white-ruffed-lemur-restocking-program/
  • http://www.rosamondgiffordzoo.org/assets/uploads/animals/pdf/BlackWhiteRuffedLemur.pdf

Written by Rachel Heim, December 2018