RED RUFFED LEMUR
Geographic Distribution and Habitat
Red ruffed lemurs are endemic, or native, to the island of Madagascar, located off of Africa’s southeast coast. These wild populations are found nowhere else in the world. With an extremely restricted range, red ruffed lemurs occupy only a small section of their large island. The deciduous tropical rainforests of the Masoala Peninsula, which includes Masoala National Park—Madagascar’s largest protected area—and the region immediately north of the Bay of Antongil in northeastern Madagascar are home to these Critically Endangered primates.
Their population density is reported as 11 individuals per 0.4 sq mi (1 sq km). Red ruffed lemurs are separated from members of their sister species, the black-and-white ruffed lemur (V. variegata), who is also Critically Endangered, by the Antainambalana River. There is some speculation among scientists that red ruffed lemurs might also inhabit Makira Natural Park, home to black-and-white ruffed lemurs. However, the presence of red ruffed lemur individuals here has not been confirmed. Additionally, within Masoala National Park, a possible hybrid of the red ruffed and black-and-white lemur has been reported. The two species are known to form a natural hybrid zone. At one time, before humans came into contact with the two species, scientists speculate that this natural hybrid zone was quite large.
Although red ruffed lemurs prefer to live within primary forests, where the canopy of large feeding trees provide them with residence, severe habitat destruction due to human activity has forced some individuals to take up alternate residence in secondary lowland forests.
Within their moist, tropical habitats, red ruffed lemurs reside at elevations up to 3,937 ft (1,200 m) above sea level, with an average elevation of 3,301 ft (1,006 m).
In the primate world, red ruffed lemurs are classified as prosimians; they are not considered monkeys, but rather a more ancient primate.
Size, Weight, and Lifespan
Of the approximately 100 species of lemurs (including subspecies), red ruffed lemurs are among the largest. They are also one of Madagascar’s largest primates; adults weigh between 7.5 and 8 lb (3.4–3.6 kg) and have a head-to-body length between 20 and 22 in (50–55 cm). Their tails add another 24 to 26 in (60–65 cm) to their bodies. Females tend to outweigh males.
Obesity can be a problem with captive red ruffed lemurs (those residing in zoos). These individuals have been known to tip the scales at 9.5 lb (4.3 kg).
Average lifespan in the wild is 15 to 20 years. The average lifespan for captive red ruffed lemurs is 19 to 25 years.
This striking prosimian takes its name from the ruff of rust-colored reddish hair that dramatically feathers out, like sideburns gone astray, from a coal-black face. Even their tiny black ears are lost in this wild red fringe. Completing its arresting mien is a pointy, whiskered, dog-like snout and luminous eyes that shine in the dark, thanks to a reflective layer that aids with night vision.
Just as remarkable as the red ruffed lemur’s face is its plush, rust-red (or chestnut) fur coat that cloaks its sturdy body. This luxuriant pelage acts as insulation during Madagascar’s sometimes chilly rainy season. A patch of white fur at the nape of the neck lends contrast to the rust-colored coat. Some individuals also have white fur markings on their lower hindquarters. Rarely and randomly, these white markings might appear as a ring at the base of an individual’s tail, on the hands and feet, or near the primate’s mouth.
Their hands, feet, and belly are black, as is this lemur’s long and fluffy nonprehensile tail.
Besides giving them a stunning appearance, Nature has fitted red ruffed lemurs with specific physical adaptations that help them during the course of daily life. Six specialized incisor teeth, located at the bottom front of the mouth, form a toothcomb that these prosimians use to peel certain fruits. Their toothcomb also helps them with grooming. A specialized claw, longer than the other claws and located on the second toe of each hind foot, lends further grooming assistance, allowing these fastidiously clean primates to brush their thick, plush coats.
Red ruffed lemurs are regarded as Madagascar’s most frugivorous primates, which is a fancy way of saying that they eat a lot of fruits! Fruits comprise up to 90 percent of their diet. Figs are perhaps their favorite fruit, and these prosimians have been known to engage in fig fights; that is, they’ll fight over who gets “first dibs” on a succulent fig.
Flowers, nectar, and pollen complement their meal plan. By sticking their long noses deep into a flower, red ruffed lemurs can easily access the hidden nectar.
During the dry season, when fruits are scarce, red ruffed lemurs may resort to eating leaves, shoots, and seeds.
Behavior and Lifestyle
Social animals, red ruffed lemurs live in groups with clearly defined male and female hierarchies. Females are dominant, and they call the shots. Group size depends on habitat and available food sources. Individuals might live in small communities of only 2 to 5 individuals with a home range of 62 ac (25 ha), or they might belong to a large, loosely affiliated community of 18 to 32 members with a home range of 62 ac (25 ha). Members share a common core home range, deliberately chosen for the presence of large fruit-bearing trees. Occasionally, border scuffles erupt with outside groups.
Locally, red ruffed lemurs are called varignena.
The word “prosimian” means “before monkeys.”
The word “lemur” is derived from the Latin word lemures, which means ghosts or spirits.
Red ruffed lemurs belong to the primate suborder known as strepsirrhini, which includes lemurs, lorises, and bush babies. Strepsirrhine primates are characterized by their moist muzzles, a specialized set of front lower teeth—known as a toothcomb—that assists with eating and grooming, enhanced night vision, an enhanced sense of smell that allows these primates to detect pheromones (chemical stimuli found in hormonal secretions), and, impressively, their body’s ability to produce its own vitamin C.
Except for the mongoose lemur (Eulemur mongoz) and the common brown lemur (Eulemur fulvus) found on the nearby Comoro islands, wild lemur populations are found nowhere else in the world but Madagascar. The mongoose lemur also inhabits Madagascar; it believed to be an introduced species in the Comoros.
Active during daylight hours (making them diurnal), red ruffed lemurs spend most of their time in trees (making them arboreal), high in the top layers of the canopy where they can better avoid potential predators. They are quadrupedal animals; that is, they walk on all fours. But red ruffed lemurs are most known for their spectacular leaps. Like daredevil acrobats, they hurl themselves from one tree to another, crashing through vegetation and causing a lot of commotion and branches to shake as they successfully stick their landing. Their long and bushy tails help them to balance as they perform these impressive feats.
While feeding in their treed canopy, red ruffed lemurs often hang upside down by their feet to grasp hard-to-reach fruits. They might also assume this topsy-turvy position while engaging in play wrestling with one another or during a mutual grooming session. Resting positions include hunched sitting and upright postures. These prosimians are also prone to resting on their belly or sunbathing on their back with limbs outstretched. They are able to stand upright and are good climbers. When they do decide to descend to the ground, they walk with their head pointed downward and their tail held high.
Red ruffed lemurs travel about 0.75 mi (1.2 km) through the forest each day to forage. During the wet season, when fruits are plentiful, large foraging groups are the norm. During the dry season, however, when fruits are scarce, members scatter with the hope of having more success on their own. Members later regroup. This practice of separating then coming together is known as “fission-fusion” and is in stark contrast to other diurnal lemurs who forage and move through the forest together as a cohesive group.
While foraging, mothers often “park” their babies in trees. Red ruffed lemurs have been known to chase birds of prey and other potential predators to protect their young and to distract these predators from a nearby lemur nest.
Natural predators include boa constrictors, eagles, and hawks, and the fossa (a cat-like carnivorous mammal found only on Madagascar).
The “chatterboxes” of Madagascar rainforests, red ruffed lemurs are regarded as one of the more talkative nonhuman primates. And they are loud! Their raucous calls can be heard for miles. Low grunts, cackling roars, gurgling sounds, shrieks, barks, and screeches are included in their language repertoire.
These loquacious prosimians use their calls for a variety of reasons: to stay in touch with one another while foraging in the forest; to warn off lemurs from outside groups who might try to move into their range; and to alert members of a potential predator in the area.
Red ruffed lemurs and black-and-white ruffed lemurs are reported to understand one another’s calls, even though their calls differ in frequency and pulse rate and even though these species do not interact with one another in the wild.
Scent marking is another important means of communication. Fitted with scent glands on their wrists and bottoms, red ruffed lemurs mark their territories by leaving scent trails on the branches as they travel.
When threatened, they gesture with their bushy tails to send a visual signal.
As with most nonhuman primates, grooming one another is an important activity that helps to instill social bonds.
Although red ruffed lemurs are mostly polygamous, some studies have found monogamous pairs. Males within a group more frequently mate with females from the same group. However, outside males might also enter a group’s territory to try their luck mating with ovulating females.
These lemurs reach sexual maturity at about 2 years of age and begin reproducing at about 3 years of age. They breed once a year. Males keenly monitor females for signs of estrus (the period when she is ovulating and capable of conceiving) and then do their best to entice females to copulate. The males’ mating “playbook” includes a submissive approach to a female, coupled with shrieks and squeals, and complemented with scent marking. They might also sniff and lick their genitals in an audacious display. Females get to choose their mates, as befitting of their dominant status in their group.
Breeding season coincides with the end of the dry season, May through July. This fixed season is deliberate so that the young can be born during the wet season when food is readily available. Females begin to eat more high-protein items like young leaves and flowers just before birth to help with the high levels of energy their bodies require to produce milk for their young.
An individual female goes into estrus for, at most, a few days and is only fertile for one day. After a gestation period of about 102 days, she typically gives birth to two or three infants; however, as many as six infant births are not uncommon. Ruffed lemurs are one of the few primate species who give birth to litters. Fortunately, Nature has given females six nipples so that mothers can simultaneously nurse six infants, if necessary. These tiny babies weigh less than 3.5 oz (100 g). Although they are born with fur and can see, red ruffed lemurs are not as well developed at birth as lemur species who have longer gestation periods. For example, infant red ruffed lemurs are unable to cling to their mother, forcing the mother to pick up her babies one by one, using her mouth, when she needs to move them.
Unlike other diurnal prosimians, red ruffed lemur mothers do not carry their babies around on their backs as they go about their day. (With multiple infants, loading them all onto her back would hinder her movements.) Instead, mothers keep their infants ensconced in nests constructed from twigs, leaves, vines, and fur that are 33–66 ft (10–20 m) off the ground. A mother usually remains with her babies the first few days of their lives. However, if she must leave the nest, the infants’ father guards them.
After a week or two, a mother rejoins members of her group to forage, after she safely parks her babies in a tree within the group’s core home range. Other group members might help her out by babysitting her young while she travels through the forest. Shared infant care, or alloparenting, is commonly practiced in red ruffed lemur groups, and the practice eases the maternal burden of mothers. Nevertheless, infant mortality is high. Approximately 65 percent of young do not reach three months of age; many of them die by falling from trees to the forest floor. Those who survive develop rapidly. They begin moving around at about one month old, when they may attempt to follow their mother. At four months old, they are considered weaned.
The presence of healthy populations of red ruffed lemurs is indicative to the overall health of Madagascar’s rainforest. As frugivores, red ruffed lemurs disperse seeds via their feces throughout their habitat and thereby encourage new plant growth. These prosimians are also vital pollinators. While feeding on the nectar of tubular flowers of certain hardwood trees, their narrow and long prominent snouts become coated with pollen, which red ruffed lemurs then carry from flower to flower, helping to further regenerate their habitat. Unfortunately, the same fruited hardwood trees favored by red ruffed lemurs are also the first trees to be cut down illegally by loggers.
The red ruffed lemur is listed as Critically Endangered by the International Union for Conservation of Nature (IUCN 2018), appearing on the IUCN Red List of Threatened Species. This precarious status means that these primates are only one step away from extinction.
After political unrest shook Madagascar in early 2009, environmental programs collapsed—leaving red ruffed lemurs in peril.
The greatest threat against red ruffed lemurs is habitat loss. Slash and burn agriculture, illegal logging of precious wood (rosewood and ebony), and fuel wood harvesting have collectively accelerated deforestation and erosion, which in turn has altered microclimates, leading to droughts, forest fires, and soil degradation. Land has also been re-purposed for the mining industry.
Poaching further jeopardizes these primates. Red ruffed lemurs are killed for their flesh (bushmeat), which is eaten by locals—many of whom are desperately poor. A lack of alternative protein sources in rural villages has resulted in an increase in poaching and has led to the emergence of a commercial bushmeat trade.
Red ruffed lemurs are victims of the illegal pet trade. Infants are kidnapped from their mothers and sold; mothers are killed during the capture of their babies.
Destructive cyclones are common to Madagascar and pose an additional threat to these primates.
The red ruffed 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.
Populations residing within Masoala National Park are, in theory, protected. However, as is often the case with endangered species, laws created to protect them are largely ignored and difficult to enforce.
Conservationists call for increased regulation and enforcement of existing laws against hunting and logging within the species’s range.
In early 2014, primatologists from Bristol Zoological Society, Conservation International, and the IUCN Species Survival Commission Primate Specialist Group developed an emergency three-year action plan for Madagascar’s lemurs. Key objectives included: stabilizing the immediate crisis; laying the groundwork for longer-term actions; the promotion of ecotourism, which would provide livelihoods for the rural poor; and the creation of permanent field stations staffed by local and international researchers, which would serve as training grounds for native (Malagasy) scientists and concurrently help to deter illegal hunting and logging.
The Lemur Conservation Foundation (LCF) partners with scientists and conservationists on the ground in Madagascar. LCF is a managing member of the Madagascar Fauna and Flora Group (MFG), an international consortium of zoos working together to conserve Madagascar’s spectacular wildlife and their habitats through field research, conservation breeding, technical advice, and training to Malagasy institutions and biologists.
Additionally, LCF operates the Myakka City Lemur Reserve, a 130-acre lemur reserve in rural Manatee County, Florida, USA. Red ruffed lemurs are among the reserve’s primate residents.
The Duke Lemur Center (DLC) operates a “living laboratory” in Duke Forest, North Carolina, USA, where lemurs, including red ruffed lemurs, reside. Here, in a wooded, wild environment, scientists study these primates intensively and non-invasively. (A statement on DLC’s website: “We do not allow research that will harm our animals in any way.”) DLC’s scientific endeavors span an array of disciplines, from behavior and genomics to physiology and paleontology. The center is recognized as a global authority on lemur veterinary medicine.
Conservation biology is another key aspect of DLC’s work. To protect the world’s only wild lemurs and the biodiversity they represent, the DLC works in Madagascar with local Malagasy communities to preserve lemurs’ natural habitat.
DLC also works with accredited institutions to develop and adhere to Species Survival Plans (SSPs), which use carefully planned conservation breeding programs to create a “genetic safety net” for rare and endangered species.
Written by Kathleen Downey, December 2018