Long Tailed Macaque Skull measures 3.9 inches. Long Tailed Macaque Skull is museum quality polyurethane resin cast. Known as Crab Eating Macaque Monkey

The body fur of Long Tailed Macaques or Crab Eating Macaque Monkey tends to be grey-brown to reddish brown. These colors are always paler ventrally.

The face is brownish-grey with cheek whiskers. The eyes are directed forward for binocular vision. The nose is flat and the nostrils are narrow and close together.

Long Tailed macaques have shovel-shaped incisors, conspicuous canines, and bilophodont molars. The tooth formula is I 2/2, C 1/1, PM 2/2, and M 3/3.

The body length, not including the tail, is 40 to 47 cm. The greyish- brown or reddish colored tail is 50 to 60 cm. Long-tailed macaques exhibit sexual dimorphism in size. The average weight for males is 4.8 to 7 kg and 3 to 4 kg for females, approximately 69% of average male weight.

In Sumatra, each social group of Long Tailed macaques contains an average of 5.7 males and 9.9 adult females.

Females outnumber males, indicating that males have more mates available to them than do females, both sexes may mate with multiple partners.

The alpha male, or highest ranking male, of the group has the greatest access to mates of any males, and sires the most offspring.

As in all primates, there is an extended period of juvenile dependence. Long Tailed macaque females provide the bulk of the care for offspring.

The young receive nourishment, encouragement, grooming, protection, and teaching from the mother. Young females are likely to remain in the troup into which they were born, whereas males are likely to emmigrate at or near sexual maturity.