The Gray mouse lemur is a primate, not a rodent, despite its name and appearance. Currently not much is known about this species of lemur. The mouse lemurs are the smallest of the lemur species, with the gray mouse lemur being the largest of them. They are mostly gray in color, in a range of shades going from light to dark, with some change in color at different times of the year. Gray mouse lemurs rely on their senses to survive, including good night vision and a keen sense of smell. Using a combination of these senses they are able to quickly avoid predators.
The Gray mouse lemur inhabits the western coasts and the south-eastern part of Madagascar, and mostly occurs on drier coasts, in deciduous or spiny forests, secondary forest, including plantations, and semi-arid thorn scrub.
Gray mouse lemurs are nocturnal and arboreal. In the daytime they sleep in leaf nests or hollow trees and at night they hunt for food. They can be described as solitary but social. Females sleep in groups numbering two to nine, while males sleep alone or in twos. At night both genders go foraging alone. Activity times differ between the genders: in the dry season, the female is in hibernation for a long period, during which the energy conversion and metabolism functions are at a minimum. In this way, females often survive through the dry season when there is little food, whereas males remain active. A male has a home range that is twice as large as that of a females, and this is expanded during the breeding season. Both genders exhibit territorial behavior and will mark their territories with urine and feces.
Gray mouse lemurs are mainly insectivores. They sometimes eat small reptiles like chameleons and tree frogs. Plants, leaves, flowers and fruits are also part of their diet.
The Gray mouse lemur has a polygynandrous (promiscuous) mating system, with both males and females having multiple mates, but studies show that females do show indirect mate selection behavior (selected polyandry). This study showed that during their one night of receptivity, females mated with 1–7 males, but avoided or counteracted males that tried to monopolize mating. The female uses a specific call of high-frequency when ready for mating. The breeding season for these lemurs goes from September to March. Females typically produce twins, following a gestation period of about 60 days. They may give birth to two litters every year. Young reach independence in about two months, being able to breed before they are one year old. Related females typically stay in the same area once they reach maturity, whereas males disperse.
The Gray mouse lemur presently faces no significant threats and it is not thought to be at risk from extinction. However, because of the large-scale habitat loss throughout its range, due mainly to cattle grazing and agriculture, the population of gray mouse lemurs is likely to be in decline. This species is sometimes also hunted for the pet trade.
The IUCN Red List and other sources do not provide the Gray mouse lemur total population size. However, it is amongst the most abundant, widespread, and adaptable of the lemur species. It is one of the least threatened as well. Overall, Gray mouse lemurs are classified on the IUCN Red List as Least Concern (LC) but its numbers today are decreasing.
The Gray mouse lemur may regulate populations of insects and small reptiles upon which it preys. To the extent that they are food for predators (owls, snakes), these lemurs may impact local food webs.