The conservation status of brown lemurs is partially due to their restricted geographical area. Their primary threat is habitat destruction. Habitat destruction is largely the result of the explosive growth rate of the human population of Madagascar. This species is placed in a somewhat lower risk category (Vulnerable) because of its presumably large wild population and occurrence in a number of protected areas.
For red-fronted lemurs, the western habitats are largely at risk because of burning and clearing of land for pasture. In the east, the chief hazards are the slash-and-burn agriculture and forest cutting for fuel wood and construction. This subspecies occurs in some protected areas of Madagascar and can be found in captivity in 22 zoos worldwide where approximately 100 individuals are held.
Forest destruction is the primary threat to the survival of common brown lemurs. They are also hunted throughout much of their range. This subspecies is found in protected areas in Madagascar, and may be one of the lowest risk subspecies of brown lemur. Common brown lemurs have bred in captivity and there are currently about 140 animals at 40 institutions worldwide.
The white-fronted lemurs are threatened by the destruction of Madagascar's eastern rain forest for slash-and-burn agriculture. This animal is also hunted for food throughout most of its range. Presently, it does exist in protected areas in Madagascar. White-fronted lemurs do breed in captivity, and there are over 200 animals in captivity at more than 40 zoos worldwide.
Forest destruction is the primary threat to the survival of collared lemurs as well. They too, are hunted for food throughout much of their range. In addition to this, they are occasionally trapped for the pet trade. Collared lemurs occur naturally in only one of Madagascar's protected areas, but have been introduced into two others. Approximately 40 collared lemurs are currently in captivity in 6 institutions worldwide.
Sanford's lemurs are also threatened by forest destruction. This subspecies, however, does appear to be able to survive in slightly degraded habitats. Although Sanford's lemurs are found in protected areas in Madagascar, the level of protection varies among the reserves. This is because poaching and brush fires are common events in many of Madagascar's nature reserves. There are only two captive breeding groups of sanford's lemurs.
US Federal List: endangered
CITES: appendix i
IUCN Red List of Threatened Species: near threatened