Figure 1. The golden lion tamarin (Ben) The golden lion tamarin (scientific name Leontopithecus rosalia ) is one of the most endangered monkeys today. As its name suggests, golden lion tamarin has a mane like that of a lion, although the tamarin is not from the feline family. Its fur is very attractive, with combination of rich colors including orange, brown, and black. It is almost the size of a squirrel, having an average length of 25 centimeters, and weighing about 0.5 kg. Males are generally larger than females, although they look the same. The golden lion tamarin is commonly found in Brazil. About 1,500 individuals live in the wild, particularly in the tropical forest of Rio de Janeiro and Espiritu Santo. On the other hand, an estimate of 400 individuals are kept in zoos all over the world. Although they prefer the primary forest, they can also be found in secondary forest and some cultivated areas. Swamp forests also provide them a favorable habitat with its vines and bromeliads aiding their survival. The vines hide these little monkeys from the watchful eyes of their predators, while the bromeliads provide them with water and insects and other small vertebrates which serve as their foods. The golden lion tamarin is omnivorous. About 80% of its food intake is fruits. During the drier seasons when fruits are not readily available, it feeds on gum, nectars, insects and small vertebrates. The golden lion adapts well with their environment. They live in social groups, usually consisting of a male, a female, and younger individuals. They keep active during the day, lurking around the forest looking for food. When night falls, they settle in tousled shrubs or in tree holes. As with most of the activities in the day, sleeping is also done in groups. This choice of sleeping environment is primarily for protection from their predators. These small tight places also keep them warm at night. “Population densities across vary due to the destruction of their habitat and the extremely low numbers of golden lion tamarins in the wild. Population distribution is based on size of the area, weather conditions, and availability of food. In the largest protected area in which they are found, there are about 12 individuals per square kilometer”. However, population is largely lower in other areas with poorer conditions, where only 3 to 4 individuals are found per square kilometer. Because of the low population densities, golden lion tamarins experience less competition for food resources. There used to be around 200 individuals in1970. “After more than 30 years of conservation efforts, their number is estimated to include more than 1,000 individuals. Successful re-introduction program can be credited with 1/3 of this number. However, because of the extreme fragmentation and degradation and loss of forest, there is little room for expansion”. Reproduction is an important part in maintaining the specie’s population. The peak mating season is April and May. After a gestational period of about 130 days, the mother tamarin gives birth to one, or more often, twin liters. Golden lion tamarins also give birth to triplets and quadruplets, although the survival rate of the liters is very low. Birth season is between September to March. Golden lion tamarins are monogamous and they help each other in bringing up their child. The mother feeds the liter,