Diademed Sifaka, Propithecus diadema
The diademed sifaka (Propithecus diadema) is also commonly called the diademed simpona. It is one of the many endangered species of lemur and is native only to the island of Madagascar. It is thought that this large sifaka hold one of the largest ranges of all sifakas, although a conclusive study has not been conducted. It prefers habitats at altitudes between 656 and 2,624 feet within lowland forests and 2,624 to 5,084 feet within certain areas of subhumid forests.
Its range extends from Onive and Mongoro Rivers in the south to Mananara River in the north. One isolated population in the south of Madagascar have been found to vary in color from other populations, even holding a completely black individual. It is not known whether this population is a separate species or subspecies of the diademed sifaka.
The diademed sifaka is distinct from other species of sifaka due to its larger size and unique markings. It can reach a total body length of up to 3.4 feet, of which the tail consists of half. Its fur is soft and typically creamy white in color. Long fur rings the face, giving it a crowned or “diamed” appearance from which its name is derived. This crown of fur is typically grey or black in color, as are the face, ears, feet, and hands. The upper back and neck of this lemur are a darker grey in color, while the lower back and belly are usually lighter grey or even white. The lower limbs and base of the tail are usually golden yellow, while the tail itself is white. Males have a scent gland on the chest or throat that is a burnished red color.
The diademed sifaka prefers to live in groups of two to ten individuals, constituting a mixture of males and females. Both males and females will use scent markings to designate and defend territories ranging between 62 and 125 acres. It is highly aggressive in this defense with other members of its species, but it does not mind sharing territory with other lemurs such as the Common Brown Lemur or the Red-bellied Lemur.
The diademed sifaka is thought to travel a distance of one miler per day searching for food, the longest distance of all sifakas. It is able to exert a large amount of energy due to its diet of twenty-five different plant species, and will consume leaves, fruits, flowers, and seeds depending on the seasons. It is thought that two species within this diet give the lemur high concentrations of alkaloids, which allow it to travel so far and even leap vertically at speeds of up to 18.6 miles per hour.
At two to three years of age, the diademed sifaka will reach the age of sexual maturity, with males following behind females at a slower rate. Although little is known about the reproductive habits of this sifaka, it is thought that females can only mate a few days a year. As is typical for lemurs, females are dominant and will have a large choice of mating partners. Typically only one baby sifaka is born.
The diademed sifaka is one of four sifakas in a close-knit group within the genus Propithecus. The other members of this group include the silky sifaka, the golden-crowned sifaka, and Milne-Edwards’ sifaka. All four of these species share similar reproductive behaviors, black faces, strong leaping capabilities, social structure, and a lifetime expectancy of up to eighteen years.
In 2002, the estimated population of the diademed sifaka ranged only between 6,000 and 10,000 individuals in the wild. As a result, the IUCN listed it is “Critically Endangered”. The main threat to these lemurs is habitat destruction due to shifting cultivation methods that occurs even in protected areas. Due to overpopulation on the island of Madagascar, many of the rural poor are forced to find available forestlands, slashing and burning the trees to create grazing land and areas to plant crops. Natural predators of the diademed sifaka include the Nile crocodile and the fossa, a cat-like carnivore that is native to Madagascar.
Image Caption: Diademed Sifaka (Propithecus diadema) at Mantadia National Park, Madagascar. Credit: C. Michael Hogan/Wikipedia