Because of their hardy nature and high availability from India, the rhesus macaque (Macaca mulatta) is usually the animal of choice to conduct research on human and animal health-related topics. They are commonly used in vaccine and other pharmacological research, which was the case with the three rhesus macaques who retired from biomedical research at a University (the University did fund the building of their enclosures) to Noah's Ark in early 2015. They are an extremely adaptable and broad-ranging primate, inhabiting many diverse habitats, including snowy regions, semi-desert areas, dense forests, and especially urban areas throughout China, India, Pakistan, Burma, Laos, Vietnam, Nepal, and Thailand. They are very social and intelligent primates and, in many places, have learned to use human encroachment and deforestation to their advantage, surviving on scraps of the cities they live in. They are opportunistic foragers and will consume everything from flowers and grass to bird eggs and bugs. They usually weigh anywhere from 10-20 pounds, depending on geographic region, sex, and age, have a lifespan of roughly 25 years old and are not considered a threatened species.