The red-ruffed lemur (Varecia rubra) is a large quadrupedal lemur inhabiting a very small area of northeastern Madagascar. Ruffed lemurs are some of the most strikingly beautiful of all lemurs and have a thick coat of deep chestnut red fur, well suited to the oftentimes wet and chilly environment of Madagascar’s tropical rain forests.
Red ruffed lemurs are diurnal, with peak activity occurring in the early morning and in the evening. Their diet consists mostly of fruit, nectar and pollen–they are considered the most frugivorous of all the lemurs. Small amounts of leaves and seeds are also consumed, primarily during the dry season when fruit and nectar is scarce or nonexistent. When appropriate flowers are available, the lemurs eagerly feed on nectar by sticking their long noses deep into the flower. During this feeding, the flowers are not harmed, but the lemur’s snouts become coated with pollen, which is then transported to other flowers. Thus, for certain species of plants in the tropical forests of Madagascar, the ruffed lemur is an important pollinator. Unfortunately, many of the larger fruit trees essential for the survival of the ruffed lemur are also regarded as the most desirable hardwoods by logging interests, and are often the first to be cut down when a forest is selectively cut. Thus, the presence of healthy populations of ruffed lemurs is considered an important indicator of the health of a tropical forest.
In the wild ruffed lemurs seldom descend to the ground, preferring instead to spend their time in the top layers of the canopy. Their movement through the trees is often spectacular. The animals will hurl themselves, often without hesitation, from one tree to another, landing at a lower level of a neighboring tree in a spectacular crash of vegetation. During feeding, the ruffed lemurs will dangle from the delicate terminal branches of a tree, with only their feet grasping the most slender of branches, in order to grab a hard-to-reach food item, or to engage in play wrestling or mutual grooming with another animal.
Ruffed lemur reproduction is highly seasonal. The animals breed in Madagascar between May and July with most infants born in September and October after a 102 day gestation. In North Carolina, breeding usually occurs in December/January with births in April or May. Unlike most lemurs, ruffed lemur females give birth to litters of up to six infants (two or three is more typical) in well concealed, well constructed nests 10 to 20 meters up a tree. Ruffed lemurs are the only diurnal primates in the world to keep their infants in a nest. Females can nurse up to six infants simultaneously. Infant ruffs are not as well developed at birth as is typical for other lemurs, which is not surprising given the brief gestation period. At birth, infants are not capable of grasping the mother, so if she needs to transport them, she simply picks up one infant at a time in her mouth. Mothers generally move their infants away from the nest after a week or two, at which point they simply leave them parked in a tree while foraging nearby. In the days following birth, if the mother needs to leave the nest, the infant’s father will stand guard close by. Infants develop rapidly, and by three or four weeks they are capable of at least attempting to follow their mother on their own. Not surprisingly, infant mortality appears to be very high for this species, with 65% of infants failing to make three months of age, due to accidental falls and related injuries.
Ruffed lemurs appear to have a variable social system which changes depending on the season and the quality of their habitat. In some areas of Madagascar, the animals are found in small groups of two to five individuals, with a home range of 25 ha. In other areas, loose affiliations of between 18 and 32 animals occupy home ranges around 60 ha in size. All group members use a common core home range, and groups are occasionally aggressive towards other groups at the borders of these territories. There is a strong correlation between the location of home ranges and the location of the largest fruiting trees in the area. Females are the driving force in group dynamics and are always dominant to males. Ruffed lemurs will form larger groups during the wet season when food is plentiful, and disperse during the dry season in search of scarcer fruit. When foraging for fruit, large groups might fragment completely as individuals go their separate ways, which is in striking contrast to other diurnal lemurs which always forage and move through the forest together as cohesive groups.
Ruffed lemurs are among the most vocal of the non-human primates. Their raucous, barking vocalizations might serve several purposes: they allow distant members of the same group to maintain contact with each other even when they are foraging separately, they warn would-be competitors of territory already occupied, and they might also serve to alert other group members of the presence of an aerial or ground predator. Natural predators that can trigger alarms in Madagascar include boa constrictors, eagles and hawks, and the fossa (a weasel-like animal found only on Madagascar). One individual ruffed lemur can set off an alarm call that will alert even the farthest ranging group members.
As many as twelve different ruffed lemur calls have been recorded at the Duke Lemur Center, and each call has a different meaning to the lemurs. Scent marking is another means of communication strongly utilized by the ruffed lemurs.
Habitat & Conservation
Red ruffed lemurs are restricted to the forests of the Masoala Peninsula near Maroantsetra in northeastern Madagascar. They have been seen just east of the Antainambalana River, which divides their range from that of the black and white ruffed lemurs. The future of wild populations of the red ruffed lemur became much brighter when, in March of 1997, the 840 square mile Masoala National Park, Madagascar’s largest protected area, was established. Previous to the establishment of this park, deforestation in their range and hunting and trapping of the ruffed lemurs for food had dramatically reduced their numbers. Principal threats to red-ruffed lemur survival are currently habitat loss and hunting. Due to the ruffed lemurs large size and apparent need for intact primary forest, it is particularly susceptible to human encroachment and possibly selective cutting of the most precious hardwoods (ie rosewood) which, unfortunately has been occurring all over Madagascar since the start of the most recent political crisis. The most recent IUCN assessment places red-ruffed lemur, with its very limited range, in the critically endangered category (despite its presence in a major national park) because of the increase in illegal logging and hunting of Varecia in conjunction with logging camps inside Masaola National Park. The captive population is managed by a Species Survival Plan. The DLC maintains 20 red ruffed lemurs (10 males and 10 females), which includes two breeding groups.