Rhesus macaque baby. The baby was later found dead in a well. Though monkeys are known to attack people, enter homes or damage property, this reported behaviour was unusual. The rhesus macaque is well known to science. Due to its relatively easy upkeep in captivity, wide availability, and closeness to humans anatomically and physiologically, it has been used extensively in medical and biological research on human and animal health-related topics. It has given its name to the Rh factor, one of the elements of a person's blood group, by the discoverers of the factor, Karl Landsteiner and Alexander Wiener. The rhesus macaque
Japanese macaque Japanese macaque is very familiar in Japan, so when Japanese people simply say "saru", they usually have in mind the Japanese macaque. The Japanese macaque is sexually dimorphic. Males weigh on average , while females average . Macaques from colder areas tend to weigh more than ones from warmer areas. Male average height is and female average height is . Their brain size is about . Japanese macaques have short stumps for tails that average in males and in females. The macaque has a pinkish face and posterior. The rest of its body is covered in brown or greyish hair.