***Please note that this article was originally written by Lauren Bucciero as a volunteer writer for the New England Primate Conservancy. The images in this article are slightly different from the original due to licensing agreements. A link to this article’s original publication on the NEPC’s webpage is available here.***
Geographic Distribution and Habitat
The red-bellied lemur is one of the rarest species of lemurs in its genus, Eulemur. This lemur is native to the tropical forests of Madagascar, a large island off the coast of Africa that is home to many unique species of animals. Madagascar is the only place in the world where all species of lemurs are naturally found. Red-bellied lemurs move quadrupedally throughout the trees at the middle to high levels of the eastern rainforest on the island. Their home range is relatively small compared to other similar species, at about 25-50 acres (10-20 hectares).
Photo Credit: IUCN Redlist
Size, Weight, and Lifespan
The red-bellied lemur averages 14-16 in (35-40 cm) in length and weighs approximately 4-6 lb (2-3 kg). Their tail is longer than their bodies, averaging 20 in (50 cm) in length and, although it is not prehensile, it is very important for balance. The lifespan of a red-bellied lemur is approximately 20-25 years, both in the wild and in captivity.
WHAT DOES IT MEAN?
Relating to the anus and genital region.Gut Microbes:
Bacteria that live in the intestinal tract.Incisors:
Narrow-edged teeth at the front of the mouth, adapted for cutting.Monogamous:
Having only one sexual partner.
Red-bellied lemurs are dichromatic, a form of sexual dimorphism in which males and females of the same species differ in color. Males have reddish-brown fur with white, teardrop patches around their eyes. These white patches are not white fur, but rather bald spots. Males have a scent gland on the top of their head. Female red-bellied lemurs have similar reddish-brown coloring, but have white bellies. They have no, or barely visible, white patches around their eyes. Both sexes have black tails.
Red-bellied lemurs are almost exclusively herbivores, but they also eat small amounts of invertebrates like insects. Their diet typically consists of flowers, leaves, and large amounts of fruit. The red-bellied lemur has been documented eating from over 67 different types of plants species.
Behavior and Lifestyle
Red-bellied lemurs are social animals. They live in small groups of 2 to 6 individuals, usually consisting of a mated pair and their offspring.These lemurs are cathemeral, meaning they can be active during both the day and night, depending on the season and food availability. However, they are usually most active during the day. Daily Life and Group Dynamics
Female red-bellied lemurs are dominant over males in a group. Females usually take the lead on foraging expeditions. During feeding, the group employs a sentinel to warn other members of potential danger, such as the presence of a predator. Red-bellied lemurs’ biggest predators are birds of prey, like raptors, and the fossa, a cat-like carnivore native to Madagascar. If danger is sensed, the sentinel gives off an alarm call that causes the other group members to freeze (sometimes for up to 15 minutes) or flee to find safety if necessary.
The group bonds through grooming activates. The lower incisors of the red-bellied lemur are designed like a comb for this purpose. Studies have also shown that the red-bellied lemur’s highly social behavior and close physical contact is linked to the group’s health and responsible for maintaining a healthy gut microbes among group members. Individuals’ gut microbes were analyzed and determined to closely resemble those of the other group members. Researchers suggest that having similar gut microbes within the group synchronizes the immune defenses of each member and likely prevents individuals from contracting dangerous infections that would put the entire group at risk.
The red-bellied lemur’s bottom incisors are designed like a comb for social grooming.
Their tail is longer than their bodies.
Red-bellied lemurs drool on toxic millipedes to neutralize the toxins and make them safe to eat.
Due to their small home range, vocal communication is not as important as other forms of communication for red-bellied lemurs. For example, although males are the only gender with a scent gland located on their heads, anogenital and palmar scent marking is common in both males and females to establish territory. Touch, body postures, and facial expressions send many different signals including, play, mating, and aggression.
Although vocal communication is less common, it is used under certain circumstances. As mentioned earlier, the sentinel that serves as a look-out during feeding will give an alarm call if potential danger is perceived. This vocal warning consists of a series of low grunting sounds. The red-bellied lemur’s normal vocalizations are said to sound like the grunting of a pig; however, they have also make a sound similar to a cat’s meow.
Sexual maturity is reached around 2 years of age for both male and female red-bellied lemurs. At that time, they find a mate and form a monogamous bond.A female’s estrus cycle lasts one month, during which time she has a high fertility window of 1 to 2 days. If she is impregnated during that time, the gestation for the pregnancy is approximately 120 days. She gives birth between September and October, usually to one offspring. Twins are rare.The birth weight of a red-bellied lemur is a mere 2-2.5 oz (60-70 grams). All red-bellied lemur infants have female coloring until about 6-7 months of age, at which time the males begin to develop their white eye patches. Infant mortality rate is unfortunately very high. About 50% of all red-bellied lemur births result in death of the newborn. If the offspring survives, the infant is fully dependent on the mother for the first two weeks of its life and is carried on the mother’s belly during that time. After that period, the infant is then carried on the back of both the mother and father for another month, until the mother rejects the infant at 5 weeks. At that time, the father takes over carrying the offspring until he or she is fully weaned and independent at about 3 to 5 months. The offspring remains within the group for a period of 2 to 3 years until they leave to find their own mate. One generation of red-bellied lemurs is 8 years.
Because red-bellied lemurs eat a diet that is rich in fruits and other plants, their ecological role consists of being an important seed dispenser. Many plant species require their seeds to pass through a digestive tract in order to properly germinate and grow. The red-bellied lemur is responsible for this process, as well as adequately spreading the seeds to different locations.
Unfortunately, all lemur species face the highest threat of extinction among primates. As for the red-bellied lemur, the International Union for Conservation of Nature lists this species as Vulnerable (IUCN, 2008). The greatest threat the red-bellied lemur faces is rainforest destruction due to slash and burn practices for agriculture, as well as logging and mining. Other threats include being hunted for food and skins, as well as being captured for the live animal trade.The estimated wild population of red-bellied lemurs is thought to be 10,000 to 100,000 individuals; however, the population is unfortunately declining at this time. One issue that is thought to contribute to the decline in population is that when food supplies are low, many lemur species do not engage in breeding. With the rapid destruction of their habitat, more and more lemurs are not producing offspring and the red-bellied lemur’s population numbers continue to drop.
Fortunately, there have been many regulations put in place to protect this species. Right now, wild populations of red-bellied lemurs can be found in five different national parks, two strict nature reserves, and six special reserves throughout Madagascar. As of 2009, there were a reported 165 individuals throughout the world in captivity in zoological collections. There are laws in place to protect this rare species from being hunted or captured for trade. The red-bellied lemur is listed on Appendix I of the Convention on International Trade in Endangered Species (CITES). CITES is an international agreement between governments that put regulations in place to ensure the trade of wildlife and plant species does not put the survival of that species at risk. Under Appendix I, movement of the red-bellied lemur is controlled and trade is only permitted under specialize circumstances.There is hope for survival for the red-bellied lemur. Continuing to spread awareness about the issues of rainforest destruction, supporting companies that are ecofriendly, donating to causes that promote conservation of primates and their habitats, promoting ecotourism, and encouraging others to take part in these efforts are all wonderful ways to help the red-bellied lemur increase their population and thrive.