Madame Berthe's Mouse Lemur

## Description

Madame Berthe's mouse lemur is the smallest primate in the world and can be found only in western Madagascar. It has a short, dense dorsal pelage that is bicolored cinnamon and yellow ochre. The middorsal stripe is tawny in color. The midventral area of the lemur is chamois in color while the flanks are a mixture of pale chamois and light pale neutral gray. The dorsal and ventral underfur is neutral blackish neutral gray in color. The tail has short hair that is tawny. The crown and ears are also tawny in color. The area between the eyes is cinnamon in color and the hands and feet are dull beige.

## Distribution

Madame Berthe's mouse lemurs live chiefly in Kirindy Forest in Madagascar. Because of their limited spread, it is thought that they are specialist creatures that will only live in that one specific environment.

## Behavior

Madame Berthe's mouse lemurs are arboreal nocturnal and generally solitary. They prefer to forage singly but will gladly interact with other members of their species; they may also sleep alone or next to one or more lemurs. Be it alone or in a group, during the day these small creatures usually sleep in leaf nests in trees, or without a nest, in hole-like structures. Social interactions include bouts of mutual grooming or huddling (an activity that can last up to 23 minutes). They may also chase each other, bite and grab. Unlike other species of lemur, Madame Berthe's mouse lemurs do not hibernate during the cold-dry season, instead, they compensate for food scarcity with a larger than average home range. Males have a home range of about 4.92 hectares (12.2 acres), while females have a home range of about 2.50 hectares (6.2 acres). Females tend to remain in a home range that is close to or includes their place of birth. Males, however, tend to disperse from their place of birth. The home ranges of individual lemurs tend to overlap with each other, with female home ranges overlapping with that of one or two other females, and male home ranges overlapping with that of up to nine other males.

## Diet

Madame Berthe's mouse lemurs are omnivores. They mainly feed on fruits and flowers of different tree and shrub species, insect secretions, gum, arthropods, and small vertebrates like geckos and chameleons.

## Reproduction

Madame Berthe's mouse lemurs have a polygynandrous (promiscuous) mating system in which both the males and the females have multiple partners. Their breeding season occurs in November and females give birth to altricial (helpless) young.

## Population

### Threats

The main threats to Madame Berthe's mouse lemurs include deforestation and habitat degradation from Slash-and-burn agriculture, illegal logging, and charcoal production. Despite that the Menabe-Antimena Protected Area has been established to protect the Kirindy Forest and the surrounding areas, this has been poorly enforced and deforestation proceeds unhindered. If deforestation continues at the current rate, it is estimated that Madame Berthe's mouse lemurs will become extinct within 10 years.

### Number

According to the IUCN Red List, in 2005, the total population size of Madame Berthe's mouse lemur was estimated at no more than 8,000 mature individuals. Currently, this species is classified as Critically Endangered (CR) on the IUCN Red List and its numbers today are decreasing.

### Ecological niche

Madame Berthe's mouse lemurs eat a wide range of fruits and thus may contribute to local seed dispersal. Due to their small size, they also serve as prey for many predators including owls, snakes, mongooses, fossas, and civets.

## Fun Facts

Madame Berthe's mouse lemur was first discovered in 1992.

This mouse lemur is named after the conservationist and primatologist Berthe Rakotosamimanana of Madagascar.

Mouse lemurs have the smallest known brain of any primate, at just 0.004 pounds (2 grams).

Lemurs and mouse lemurs were announced by the IUCN as the most endangered of all vertebrates.

In 1992, there were only two known mouse lemur species and by 2016, there were 24! It was estimated that the 24 mouse lemur species evolved from a common ancestor 10 million years ago.