Madame Berthe's mouse lemurs (Microcebus berthae) are endemic to Madagascar. More specifically, they are known to inhabit the Kirindy/CFPF forests in the southwestern Menabe region of the island. While Madame Berthe's mouse lemurs have also been found in surrounding areas, such as Ambadira and the Andranomena Special Reserve, their range is relatively small (less than 220 square kilometers), and none have been found north of the Tsiribihina River. (Andrainarivo, et al., 2012; Schwab and Ganzhorn, 2004)
Madame Berthe's mouse lemurs inhabit the dry deciduous forests of southwestern Madagascar, at elevations up to 150 meters. These animals face numerous challenges in their highly specific habitat including wide daily and seasonal temperature fluctuations, seasonal food scarcity, especially of fruits and arthropods and a seven-month dry season. ("Kirindy reserve, Madagascar", 2008; Andrainarivo, et al., 2012; Dammhahn and Kappeler, 2013; Schwab and Ganzhorn, 2004)
With body lengths of 9 to 11 cm, tail lengths of 12 to 14 cm and an average weight of 30.6 g, Madame Berthe's mouse lemurs are the smallest known living primates. Their dorsal fur is reddish, with a darker midline stripe running from the back of their shoulders to their tail. Their ventral fur is creamy or pale grey. Their face is more brightly colored, especially around their eyes, which are encircled by cinnamon rings and bisected by a white stripe. Like all mouse lemurs, Madame Berthe's mouse lemurs have extremely large eyes equipped with a tapetum lucidum adapted for nocturnal foraging. Likewise, these animals have bare digits, a grooming claw on their second toe, a toothcomb comprising the canines and incisors and a long tail. This species does not show sexual dimorphism. ("ARKive", 2013; Czaplewski, et al., 2011; Gron, 2009)
Information regarding the mating system and behavior of Madame Berthe's mouse lemurs is limited, though there are several factors that might indicate a promiscuous mating system. Such indications include scramble competition, including significant home-range overlap, with male average home ranges (4.92 ha) about twice those of females (2.50 ha). Likewise, the proportionally large testicle size in males, moderate estrous synchrony, varied sleeping association patterns and lack of sexual dimorphism could all indicate a promiscuous mating system. (Dammhahn and Kappeler, 2005)
Madame Berthe's mouse lemurs breed once a year in November. Though data are lacking concerning their specific reproductive patterns, they are thought to behave similarly to gray mouse lemurs (Microcebus murinus), which have two-month gestation and nursing periods. This has been supported by the trapping of pregnant Madame Berthe's mouse lemurs in December and the trapping of juveniles in March and April. After nursing their one to three young to independence, female gray mouse lemurs, and presumably Madame Berthe's mouse lemurs, spend the next four to six weeks storing body fat before entering daily torpor during the dry season. (Dammhahn and Kappeler, 2013)
Little is known about the parental investment of Madame Berthe's mouse lemurs, but, as in other mouse lemurs, the female likely provides care for the altricial young for about two months until they are weaned. (Dammhahn and Kappeler, 2013)
There is no information available regarding the lifespan of Madame Berthe's mouse lemurs, but their close relative, gray mouse lemurs are known to live about five years in the wild and up to fifteen in captivity. (Gilissen, et al., 2001)
Madame Berthe's mouse lemurs are solitary, arboreal and nocturnal. They move quadrupedally along tree branches, and do most of their solitary foraging about 10 meters above the ground. Madame Berthe's mouse lemurs spend approximately half of their time sleeping alone and the other half sleeping in groups of variable composition in nests of leaves, vines, tree holes, bark and branches. There are no matrilines or other dominance hierarchies present in their individualized neighborhood social groups, but further study must be conducted on their social behavior. (Czaplewski, et al., 2011; Gron, 2009; Radespiel, 2007)
A notable feature of Madame Berthe's mouse lemurs, and of other mouse lemurs, is their ability to enter into both seasonal and daily torpor. Because of their variable habitat, this ability is vital for survival. During times of drought, cold weather or when resources are lacking, they can enter into a state of torpor, significantly reducing their metabolic rate and body temperature. (Czaplewski, et al., 2011; Gron, 2009)
The average home range of males (0.049 km²) is approximately twice that of females (0.025 km²) and males have longer nightly paths (4470 m) than females (3190 m). There is a large overlap in male-male and male-female home ranges, but only a moderate overlap in female-female home ranges. This suggests a promiscuous mating system. (Dammhahn and Kappeler, 2005; Radespiel, 2007; Schwab and Ganzhorn, 2004)
There is little information specifically regarding the communication and perception of Madame Berthe's mouse lemurs, but mouse lemurs in general are known to rely primarily on olfactory and vocal communication, with visual communication playing a very limited, if unimportant, role. While mouse lemurs lack scent glands, they use scent markers, such as urine, feces, saliva and genital secretions to alarm others, confer information about sexual attraction, mark territories and recognize other individuals. For example, females in estrus are known to increase genital marking. (Gron, 2009)
The vocal cues used by mouse lemurs are specific to their species, a feature that is thought to aid in finding appropriate mating partners. Moreover, there is also great vocal variance within species, whether serving the purpose of conveying reproductive readiness or alarming others. However, because Madame Berthe's mouse lemurs are known to be a more solitary species, their use of many of these communication tactics may vary or be non-existent. (Gron, 2009)
The diet of Madame Berthe's mouse lemurs is omnivorous and consists largely of "honeydew", a sugary substance secreted by the insect larvae of Flatida coccinea. They are also known to eat gums, flowers, fruits, arthropods and small vertebrates, such as chameleons and geckos. This wide dietary range is partially due to the fluctuating availability of resources in their habitat. However, their feeding niche remains small and specialized despite seasonal variation, and becomes even narrower in the dry season. (Dammhahn and Kappeler, 2008a)
Known predators of Madame Berthe's mouse lemurs include snakes, such as colubrids and boa manditras, as well as barn owls, Madagascar owls, civets, narrow-striped mongooses and fossas. Their anti-predator adaptations include cryptic fur coloring, agility and preference for protected sleeping sites, such as holes and leaf or vine nests. These nests are often shared with other mouse lemurs. ("ARKive", 2013; Dammhahn and Kappeler, 2005; Dammhahn and Kappeler, 2008b)
Madame Berthe's mouse lemurs have received attention recently because of their status as the "smallest living primate". This primate, along with the other interesting fauna in the Kirindy Forest, has attracted curious visitors, who can take walking or automobile tours of the area (Kirindy Forest). Although their diminutive size may attract tourists, this feature is a deterrent for hunters. Likewise, Madame Berthe's mouse lemurs may also be of service to humans by dispersing seeds as a result of their frugivorous diet. ("Kirindy reserve, Madagascar", 2008)
There are no known adverse effects of Madame Berthe's mouse lemurs on humans.
Madame Berthe's mouse lemurs are considered an endangered species by the International Union for Conservation of Nature and are listed under Appendix I by the Convention of International Trade in Endangered Species of Wild Fauna and Flora. Their habitat is limited to the Menabe region in south-west Madagascar, in approximately a 900 square kilometer area that is being reduced and threatened by slash-and-burn agriculture and illegal logging. Between 1985 and 2000, about half of the forested areas in the region were destroyed. With fewer than 7,900 remaining individuals, Madame Berthe's mouse lemurs face a severe threat. However, measures to create a 100,000 ha Conservation Site in Central Menabe, as well as protect the Kirindy Forest through the establishment of a strict conservation zone have been proposed. (Andrainarivo, et al., 2012; Schwab and Ganzhorn, 2004)
Chelsea Lane (author), Yale University, Eric Sargis (editor), Yale University, Leila Siciliano (editor), Animal Diversity Web Staff.
living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.
uses sound to communicate
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
Referring to an animal that lives in trees; tree-climbing.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
an animal that mainly eats meat
uses smells or other chemicals to communicate
having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.
humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
parental care is carried out by females
union of egg and spermatozoan
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
animals that live only on an island or set of islands.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
active during the night
an animal that mainly eats all kinds of things, including plants and animals
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them
breeding is confined to a particular season
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
uses touch to communicate
Living on the ground.
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
uses sight to communicate
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
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Gilissen, E., M. Dhenain, J. Allman. 2001. Brain Aging in Strepsirhine Primates. Pp. 421-431 in P Hof, C Mobbs, eds. Functional Neurobiology of Aging. Massachusetts: Academic Press.
Gron, K. 2009. "Primate Info Net" (On-line). Mouse lemur (Microcebus) Taxonomy, Morphology, & Ecology. Accessed March 12, 2013 at http://pin.primate.wisc.edu/factsheets/entry/mouse_lemur/taxon.
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Schwab, D., J. Ganzhorn. 2004. Distribution, Population Structure and Habitat Use of Microcebus berthae Compared to Those of Other Sympatric Cheirogalids. International Journal of Primatology, Vol. 25 Issue 2: 307-330.