Bennett’s brown lemur, Red-fronted brown lemur
The Red-fronted lemur is a medium-sized species with a defined sexual dimorphism. Both males and females are the same size and display considerably long tails, but differ in their color pattern. Thus, males have a grey to grey-brown fur and a bushy reddish-brown head crown. Meanwhile, females are distinguished by a reddish-brown with a dark head crown. Individuals of both genders exhibit paler under-parts, white markings above each eye, a black muzzle. Most individuals have a dark streak, running from their muzzle up to the crown. Newborn babies of both sexes display male color pattern until 3 - 4 months old. The Red-fronted lemur hasn't been recognized as separate species for a long period of time. The name of this animal was used as a secondary name for the red-fronted brown lemur that, in turn, was commonly thought to be a subspecies of the Brown lemur.
The Red-fronted lemurs are native Malagasy animals, occupying the central western and south-eastern regions of the island. These animals can be divided into two groups: Red-fronted lemurs - those found between the Tsiribihina and Fiherenana Rivers; and Red-fronted brown lemurs - those living north of the river. Overall, their natural range extends from the Onive and Mangoro Rivers southwards to the Andringitra Massif, probably reaching the Manampatra River, whereas the eastern limit of their range is unknown. Populations in the western parts generally prefer living in dry tropical forest, while those in the western portions of their range mainly occur in moist lowland and montane forests.
Habits and lifestyle
The Red-fronted lemurs are highly social animals, forming groups of 5 - 18 individuals, consisting of both mature males and females. Each group may occupy a large territory of more than 100 hectares. Between 3 and 4.5 years old, males tend to move between groups. It may take from 6 to 12 months for them to find a new group. However, when joining a group, they typically remain with it until old age. Additionally, females in western populations are known to often leave their natal groups after reaching maturity at 23 - 26 months old. Red-fronted lemurs are cathemeral creatures that are active during both day and night. Meanwhile, they have irregular periods of activity throughout the 24-hour day. Red-fronted lemurs are tree-dwelling animals, generally spending their time in the upper canopy. When travelling among trees, they move around on all of their four legs. When travelling, these lemurs communicate with each other through a wide variety of vocalizations.
Diet and nutrition
These animals are generally frugivores, as more than a half of their diet consists of various fruits, while the other half is typically composed of leaves, flowers, insects and arthropods.
Red-fronted lemurs exhibit both polygynous (one male mates with multiple females) and polygynandrous (promiscuous) (both males and females have multiple mates) mating systems. Red-fronted lemurs mate between May and June. Females generally produce a single offspring per year, usually in early to mid-October, after a gestation period of about 120 days. During the period of lactation, mother and their newborn young live separately from the group. After a while, the babies can be seen travelling clung on their mother's belly. The infants become more agile at around one month old, when they begin riding on the back of their mother. Weaning occur at 6 months old, while the age of reproductive maturity is 2 - 4 years old in females and 3 - 4.5 years old in males.
The biggest threat to the population of this species as a whole is loss of their natural habitat due to a number of factors such as logging, clearance for pastures and fuelwood as well as the activity known as ‘tavy’ - this is when vegetation of a certain area is cut and burnt to create arable land. On the other hand, population in the southeastern part of the island faces about 1.5% destruction of their rainforest habitat. If this continues, the whole rainforest will disappear by 2020. Additionally, Red-fronted lemurs are commonly hunted and trapped.
According to the IUCN Red List, the total population of Red-fronted lemurs is unknown. However, 2,228 individuals have been estimated within Ranomafana National Park. Overall, Red-fronted lemurs are classified as Near Threatened (NT) and their numbers today continue to decrease.
These animals act as important seed dispersers of the plant species they consume, thus benefiting the ecosystem of the dry deciduous forests and rainforests, where they live.
Fun facts for kids
- As opposed to other lemurs, the Red-fronted lemurs don't live in a female-dominated society, although females do play a key role in a community life, choosing and guiding the group to food sources.
- The Red-fronted lemurs have a low metabolic rate. Hence, during the cooler season, they display decreased activity and social thermoregulation, often huddling in groups to conserve heat, where subordinate males typically huddle together.
- Red-fronted lemurs are known to be a highly vocal species, using a wide range of calls such as grunts and contact signals. One of the most common vocalizations is a nasaly "ohn" call, given out to keep the unity of the group. Another important call is the high pitched territorial "cree" and a "crou," serving as an alarm call.
- They use a system of alarm calls, which includes specific calls for each type of predator such as carnivores or birds of prey.
- In addition, the Red-fronted lemurs are able to recognize alarm calls of other lemur species.