muscles than any others. Their tails help to offset their balance while moving swiftly through the trees since their tails are about the same length as their head and body size. Sexual dimorphism is very low, with males and females being of about equal sizes. The upper and lower jaws of the Matschie's tree-kangaroos are different too in addition to them being different in body size. The upper jaw has three incisors, one canine, one premolar, and four molars, while the lower jaw has one very sharp incisor, no canines and low crowned molars. Ecology and behavior Matschie's tree-kangaroo lives in the mountainous rainforests at elevations of between . The kangaroo tends to live either alone or with very small groups, usually composed of just a female, a joey, and a male. They spend most of their time in the trees and come down occasionally to feed. They are very adept at hopping and can leap up to 30 feet (9 m). Instead of sweating, Matschie's tree-kangaroo licks its forearms and allows the evaporation to help cool its body. In the wild, it will usually feed on leaves, fruits and mosses. When kept in zoos, it feeds on apples, carrots, yams, corn on the cob, celery, kale/romaine, high fiber monkey biscuits, tofu, hard boiled eggs, and various types of tree boughs (elm, willow, etc.). In the wild, researchers have found most Matschies’ live alone or in small assemblies, containing maybe a mother and her offspring and one male. Most of the time, the groups have a sex ratio of 1:1. The Matschie's tree-kangaroos are very closely related to Dendrolagus goodfellowi, the Goodfellow's tree-kangaroo, which was once considered a subspecies of the Matschie's tree-kangaroos. Matschies’ appear to be scared of humans because they scramble around when humans are nearby and they are very difficult to find in the forests. They spend about 14 to 15 hours of their days sleeping and resting. The Matschie's tree-kangaroos are known for defending their home territory and marking their boundaries. When the temperature of the environment drastically changes at different times of the year, they are able to maintain a moderate body temperature because of their metabolic rate. Matschies’ have been found to be very susceptible to mycobacterial infections; however, the infections do not seem to be contagious because some individuals that are around infected kangaroos do not appear to get the infection. It seems