About Varecia variegata (Kerr, 1792)
Varecia variegata, the black-and-white ruffed lemur, is the largest extant member of the Lemuridae family alongside the red ruffed lemur. Its total body length ranges from 100 to 120 cm (3.3 to 3.9 ft), and adult body weight falls between 3.1 and 4.1 kg (6.8 to 9.0 lb). As its common name suggests, this species always has a coat of black and white fur, with general color patterns that typically do not vary. The abdomen, tail, hands and feet, inner limbs, forehead, face, and crown are black; fur is white on the sides, back, hind limbs, and hindquarters. Males and females have identical appearance. This species lives in the eastern rainforests of Madagascar. It occurs at low to moderate altitudes, primarily in primary forests with tall, mature trees, and prefers dense, contiguous blocks of vegetation, though it will use patchy forests when needed. There are three subspecies with slightly different geographic ranges: the white-belted black-and-white ruffed lemur is found furthest north, the southern black-and-white ruffed lemur is found furthest south, and the nominal black-and-white ruffed lemur subspecies occupies the range between the other two. Both male and female black-and-white ruffed lemurs reach sexual maturity between 1.5 and 3 years of age, but first breeding is not always successful. As males approach the breeding season, their testicles gradually enlarge over the preceding months; after successful mating with a female, their testicles gradually shrink back to their normal size. When sexually mature females enter estrus during the breeding season, their vaginas begin to open slightly, starting as a visible small pink dot and line, which stands out against the black skin around the vulva. The pink opening gradually widens over several days. Once fully open, vaginal estrus lasts 2 to 3 days. Within this period, there is a shorter 6 to 12 hour window when females are in behavioral estrus, and breeding can only occur during this time. After breeding, the female's vulva gradually closes and remains closed and black for the rest of the year. The average gestation period is 102.5 days, and litters typically contain 2 to 6 offspring. Unlike infants of other primates, black-and-white ruffed lemur infants cannot cling to their mother. The female builds a nest where infants stay until they can leave on their own. For the first two weeks after birth, the female stays with the infants almost 24 hours a day. Both males and females guard the nest. Studies show that both related and unrelated females will place their infants in communal nests and share parental care while other group members forage. This communal nesting leads to higher infant survival compared to nesting alone.
