Species of the day one hundred and seventeen: Madame Berthe’s Mouse Lemur (Microcebus berthae)
Scientific Classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Family: Cheirogaleidae
Genus: Microcebus
Species: Microcebus berthae
Size: Head-body length: 9 – 11 cm
Tail length: 12 – 14 cm
Weight: 30 g
Description: Described as a new species in 2000, the tiny Madame Berthe’s Mouse Lemur is believed to be the world’s smallest extant primate. This species has extremely large, forward-facing eyes, which have a shiny layer behind the retina that reflects light back through the eye, dramatically improving night-vision. The fur is reddish-brown on the dorsal surface with a darker stripe running down the midline of the back from the shoulders to the tail while, in contrast, the fur on the ventral surface is creamy or pale grey. The head of this species is distinctively marked with a dull white patch above the nose and cinnamon rings around the eyes. Like other mouse lemurs, Madame Berthe’s Mouse Lemur has a long tail, relatively large ears and furless/bare digits.
Habitat and Distribution: Madame Berthe’s Mouse Lemur inhabits lowland, dry, deciduous forest between sea-level and elevations of 150 metres. Endemic to Madagascar, this species is restricted to the Menabe region in the south-west of the island, south of Tsiribihina River, in an area that probably covers no more than 900 square kilometres, where it co-occurs with the much wider distributed Grey Mouse Lemur.
Biology and Ecology: Given the relatively recent discovery of this particular species limited information pertaining to its biology and ecology is currently available. A nocturnal, solitary forager, Madame Berthe’s Mouse Lemur is exceptionally agile when moving through the trees and low-level vegetation, searching for insects, fruit and small reptiles such as geckos and chameleons. While the diet of this species is extremely varied, its major food source is the sugary secretion, or “honeydew”, produced by the larvae of the insect species, Flatida coccinea. At dawn, Madame Berthe’s Mouse LEmur conceals itself amongst vegetation, often in a tangle of vines, where it may be accompanied by other individuals of the same species. Interestingly, during the cooler, dry winter months, Madame Berthe’s Mouse Lemur undergoes a daily period of torpor, lowering its metabolic rate for a few hours, which causes its body temperature to drop to ambient levels, thereby conserving water and energy. This species is heavily preyed upon by owls, civets, mongooses, snakes and even other lemurs. Mating occurs in November, with the young born, after a gestation period of around two months in January.
Status and Threats: Madame Berthe’s Mouse Lemur is classified as Endangered under the IUCN Redlist and listed on Appendix I of CITES. Like many Madagascan species, Madame Berthe’s Mouse Lemur is threatened by habitat loss due to illegal logging and slash-and-burn agriculture. With its highly restricted range and a global population estimated to be no more than 8,000 mature individuals, this species faces an uncertain future.
