Microcebus berthae, Rasoloarison, Goodman & Ganzhorn, 2000

Russell A. Mittermeier, Anthony B. Rylands & Don E. Wilson, 2013, Cheirogaleidae, Handbook of the Mammals of the World – Volume 3 Primates, Barcelona: Lynx Edicions, pp. 28-65 : 52

3.

Madame Berthe’s Mouse Lemur

Microcebus berthae

French: Microcébe de Berthe / German: Madame-Berthe-Mausmaki / Spanish: Lémur ratéon de Berthe

Other common names: Berthe's Mouse Lemur

Taxonomy. Microcebus berthae Rasoloarison, Goodman & Ganzhorn, 2000 ,

Mada- gascar, province of Toliara, Kirindy/CFPF Forest, 60 km NE of Morondava (20° 04’ S, 44° 39° E).

M. berthae is the name given to the diminutive, rufous-colored mouse lemur that was discovered in the Kirindy Forest in 1992, and it was originally thought to be M. myoxinus . Monotypic.

Distribution. WC coastal Madagascar in the Menabe region S of the Tsiribihina River.

Descriptive notes. Head-body 9.9-5 cm, tail 13-14 cm; weight 31 g. Male Madame Berthe’s Mouse Lemurs are larger than females during the breeding season; females are larger than males at all other times. It is the smallest of the mouse lemurs and very likely the world’s smallest primate. Pelage is short and dense, being bicolored cinnamon and yellow-ocher above with a distinct, darker midline stripe that extends from just behind the shoulders to the tip of the tail. The ventral coat is pale yellow-brown to pale gray. Fur on the head is brighter than on the back; the crown, ears, and tail are tawny; and furred portions of hands and feet are dull beige. There are narrow black bands surrounding the eyes, and a dull white patch above the nose. Ears are very short.

Habitat. Dry deciduous lowland forest from sea level to 150 m.

Food and Feeding. Madame Berthe’s Mouse Lemur feeds on fruits and gums, and relies heavily on sugary insect excretions and animal matter during the harsh dry season.

Breeding. This species is believed to have a promiscuous mating system based on males’ testis size, presence of sperm plugs in the females’ vaginas, and sexual-size dimorphism.

Activity patterns. Madame Berthe’s Mouse Lemur is nocturnal and arboreal. While both sexes engage in daily periods of torpor, decreasing their metabolism and body temperature to reduce energy expenditure, they do not enter prolonged torpor during the dry season. Their most common diurnal resting sites are tangles of thin branches surrounded by leaves, but they also use old nests of giant mouse lemurs ( Mirza ), tree holes, and rolled bark found in trees. Sleeping sites are located 2:5-12 m above ground. Individuals sleep alone in contrast to sympatric Gray Mouse Lemurs ( M. murinus ) that form sleeping groups. One potential reason for this may be Madame Berthe’s Mouse Lemurs’ preference for tangled vegetation as sleeping sites, which may be disadvantageous for several individuals sleeping together due to increased visibility and vulnerability to predation. Males seem to distribute their sleeping sites over a larger area than females, and females reuse the same sleeping site more often than males.

Movements, Home range and Social organization. Madame Berthe’s Mouse Lemur appears to be entirely solitary. Individuals do not form sleeping groups, except females and their young. During the night, males and females forage separately. Home ranges, however, overlap extensively and are larger among males (4-9 ha) than females (2-5 ha). Nightly movement of Madame Berthe’s Mouse Lemur appears to be more than double that of the larger Gray Mouse Lemur , averaging 4470 m for males and 3190 m for females. Madame Berthe’s Mouse Lemur is sympatric with the Gray Mouse Lemur in the Kirindy Forest; the two seem to avoid interspecific competition by means ofspatial segregation, thereby making the distribution of both rather patchy. In general, Madame Berthe’s Mouse Lemur appears to be more localized than the Gray Mouse Lemur . Densities have been estimated at 30-100 ind/km? and tend to be higher in Ambadira Forest than in Kirindy Forest.

Status and Conservation. CITES Appendix I. Classified as Endangered on The IUCN Red List. However, at the [IUCN/SSC Lemur Red-Listing Workshop held in July 2012, Madame Berthe’s Mouse Lemur was assessed as vulnerable due to an ongoing reduction in population size of more than 30% over ten years. Madame Berthe’s Mouse Lemur is threatened mainly by slash-and-burn agriculture and logging. Although adaptable and abundant where it occurs, the total population was estimated at no more than 8000 adult individuals in 2005, living in a handful of forests, most of which are still at risk of destruction and fragmentation. It is known to occur in the Andranomena Special Reserve and Kirindy Forest (part of the Menabe-Antimena Protected Area). Madame Berthe’s Mouse Lemur also was formerly found in the Analabe Reserve, but it has likely been extirpated from there. Its distributional range is less than 5000 km?

Bibliography. Dammhahn & Kappeler (2005, 2006, 2008a, 2008b), Groves (2001), Mittermeier et al. (2010), Ortmann et al. (1997), Rasoloarison et al. (2000), Schmid & Kappeler (1994), Schmid et al. (2000), Schwab (2000), Schwab & Ganzhorn (2004).

Figures

1. Gray Mouse Lemur (Microcebus murinus), 2. Gray-brown Mouse Lemur (Microcebus griseorufus), 3. Madame Berthe’s Mouse Lemur (Microcebus berthae), 4. Peters’s Mouse Lemur (Microcebus myoxinus), 5. Golden-brown Mouse Lemur (Microcebus ravelobensis), 6. Bongolava Mouse Lemur (Microcebus bongolavensis), 7. Ambarijeby Mouse Lemur (Microcebus danfossi), 8. Margot Marsh’s Mouse Lemur (Mucrocebus margotmarshae), 9. Sambirano Mouse Lemur (Microcebus sambiranensis), 10. Nosy Be Mouse Lemur (Microcebus mamaratra), 11. Tavaratra Mouse Lemur (Microcebus tavaratra), 12. Montagne d’Ambre Mouse Lemur (Microcebus arnholdi), 13. Rufous Mouse Lemur (Mucrocebus rufus), 14. Jolly’s Mouse Lemur (Microcebus jollyae), 15. Gerp’s Mouse Lemur (Microcebus gerpi), 16. Goodman’s Mouse Lemur (Microcebus lehilahytsara), 17. Simmons’s Mouse Lemur (Microcebus simmonsi), 18. Anjiahely Mouse Lemur (Mucrocebus macarthuri), 19. Mittermeier’s Mouse Lemur (Microcebus mittermeieri)

Distribution. WC coastal Madagascar in the Menabe region S of the Tsiribihina River.