Gray mouse lemur
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The gray mouse lemur (''Microcebus murinus''), grey mouse lemur or lesser mouse lemur, is a small
lemur Lemurs ( ) (from Latin ''lemures'' – ghosts or spirits) are Strepsirrhini, wet-nosed primates of the Superfamily (biology), superfamily Lemuroidea (), divided into 8 Family (biology), families and consisting of 15 genera and around 100 exist ...
, a type of
strepsirrhine Strepsirrhini or Strepsirhini (; ) is a suborder of primates that includes the lemuriform primates, which consist of the lemurs of Madagascar, galagos ("bushbabies") and pottos from Africa, and the lorises from India and southeast Asia. Colle ...
primate Primates are a diverse order of mammals. They are divided into the strepsirrhines, which include the lemurs, galagos, and lorisids, and the haplorhines, which include the tarsiers and the simians (monkeys and apes, the latter including huma ...
, found only on the island of
Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...
. Weighing , it is the largest of the
mouse lemur The mouse lemurs are nocturnal lemurs of the genus ''Microcebus''. Like all lemurs, mouse lemurs are native to Madagascar. Mouse lemurs have a combined head, body and tail length of less than , making them the smallest primates (the smallest spe ...
s (
genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
''Microcebus''), a group that includes the smallest primates in the world. The species is named for its
mouse A mouse ( : mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...
-like size and coloration and is known locally (in Malagasy) as ''tsidy'', ''koitsiky'', ''titilivaha'', ''pondiky'', and ''vakiandry''. The gray mouse lemur and all other mouse lemurs are considered
cryptic species In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...
, as they are nearly indistinguishable from each other by appearance. For this reason, the gray mouse lemur was considered the only mouse lemur species for decades until more recent studies began to distinguish between the species. Like all mouse lemurs, this species is
nocturnal Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed sens ...
and
arboreal Arboreal locomotion is the Animal locomotion, locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. Th ...
. It is very active, and though it forages alone, groups of males and females form sleeping groups and share tree holes during the day. It exhibits a form of
dormancy Dormancy is a period in an organism's life cycle when growth, development, and (in animals) physical activity are temporarily stopped. This minimizes metabolic activity and therefore helps an organism to conserve energy. Dormancy tends to be clo ...
called
torpor Torpor is a state of decreased physiological activity in an animal, usually marked by a reduced body temperature and metabolic rate. Torpor enables animals to survive periods of reduced food availability. The term "torpor" can refer to the time ...
during the cool, dry winter months, and in some cases undergoes seasonal torpor (or
hibernation Hibernation is a state of minimal activity and metabolic depression undergone by some animal species. Hibernation is a seasonal heterothermy characterized by low body-temperature, slow breathing and heart-rate, and low metabolic rate. It most ...
), which is unusual for primates. The gray mouse lemur can be found in several types of forest throughout western and southern Madagascar. Its diet consists primarily of fruit, insects, flowers, and nectar. In the wild, its natural predators include owls, snakes, and endemic mammalian predators. Predation pressure is higher for this species than among any other primate species, with one out of four individuals taken by a predator each year. This is counterbalanced by its high reproductive rate. Breeding is seasonal, and distinct vocalizations are used to prevent hybridization with species that overlap its range.
Gestation Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregna ...
lasts approximately 60 days, and typically two young are born. The offspring are usually independent in two months, and can reproduce after one year. The gray mouse lemur has a reproductive lifespan of five years, although captive individuals have been reported to live up to 15 years. Although threatened by
deforestation Deforestation or forest clearance is the removal of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated d ...
,
habitat degradation Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...
, and live capture for the
pet trade Wildlife trade refers to the of products that are derived from non-domesticated animals or plants usually extracted from their natural environment or raised under controlled conditions. It can involve the trade of living or dead individuals, ti ...
, it is considered one of Madagascar's most abundant small native mammals. It can tolerate moderate food shortages by experiencing daily torpor to conserve energy, but extended food shortages due to
climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...
may pose a significant risk to the species.


Etymology

The gray or lesser mouse lemur is named for its brownish-gray fur and mouse-like size and appearance. The genus name, ''Microcebus'', derives from the
Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...
words ''mikros'', meaning "small", and ''kebos'', meaning "monkey". The
Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
version of ''kebos'', ''cebus'', is a common suffix used for primate names, despite the fact that the gray mouse lemur is a lemur, and not a
monkey Monkey is a common name that may refer to most mammals of the infraorder Simiiformes, also known as the simians. Traditionally, all animals in the group now known as simians are counted as monkeys except the apes, which constitutes an incomple ...
. The
species name In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...
, ''murinus'', means "mouse-like" and derives from the Latin word ''mus'', or "mouse", and the Latin suffix ''-inus'', which means "like". The lemur is known locally by several names in Malagasy, depending upon the region. Around
Tôlanaro Fort-Dauphin (Malagasy Tolagnaro or Taolagnaro) is a city (''commune urbaine'') on the southeast coast of Madagascar. It is the capital of the Anosy Region and of the Taolagnaro District. It has been a port of local importance since the early 1500 ...
(Fort Dauphin), it is called ''pondiky'' . In the northern end of its range, it is known as ''tsidy'' . Around
Morondava Morondava (, from mg, morona lava "long coast") is a city located in Menabe Region, of which it is the capital, in Madagascar. It is located in the delta of the Morandava River at . Its population as of the 2018 census, was 53,510. Population T ...
, it is referred to as ''koitsiky'' , ''titilivaha'' , and ''vakiandry'' .Mittermeier, R.A.; et al. (2006). "''M. murinus''", pp. 104–107 In many cases, these Malagasy names are also used for other visually indistinguishable mouse lemur species that live within its range.Mittermeier, R.A.; et al. (2006). "Mouse lemurs", pp. 91–128


Taxonomy

As its name implies, the gray mouse lemur is a lemur, a type of primate, and belongs to the suborder
Strepsirrhini Strepsirrhini or Strepsirhini (; ) is a Order (biology), suborder of primates that includes the Lemuriformes, lemuriform primates, which consist of the lemurs of Fauna of Madagascar, Madagascar, galagos ("bushbabies") and pottos from Fauna of A ...
and
infraorder Order ( la, ordo) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and ...
Lemuriformes. Within Lemuriformes, it belongs to the family
Cheirogaleidae The Cheirogaleidae are the family of strepsirrhine primates containing the various dwarf and mouse lemurs. Like all other lemurs, cheirogaleids live exclusively on the island of Madagascar. Characteristics Cheirogaleids are smaller than the ...
, which contains the mouse lemurs,
dwarf lemur The dwarf lemurs are the lemurs of the genus ''Cheirogaleus''. All of the species in this genus, like all other lemurs, are native to Madagascar. Description Measuring 19–27 cm in body length with a tail about 16–17 cm, they are ...
s,
giant mouse lemur The giant mouse lemurs are members of the strepsirrhine primate genus ''Mirza''. Two species have been formally described; the northern giant mouse lemur (''Mirza zaza'') and Coquerel's giant mouse lemur (''Mirza coquereli''). Like all other le ...
s,
fork-marked lemur Fork-marked lemurs or fork-crowned lemurs are Strepsirrhini, strepsirrhine primates; the four species comprise the genus ''Phaner''. Like all lemurs, they are native to Madagascar, where they are found only in the west, north, and east sides of t ...
s, and
hairy-eared dwarf lemur The hairy-eared dwarf lemur (''Allocebus trichotis''), or hairy-eared mouse lemur, is one of the most scarcely known lemurs. ''A. trichotis'' is a nocturnal lemur that is endemic to Madagascar. It was originally named by Albert Günther in 1875 ...
. The mouse lemur genus ''
Microcebus The mouse lemurs are nocturnal lemurs of the genus ''Microcebus''. Like all lemurs, mouse lemurs are native to Madagascar. Mouse lemurs have a combined head, body and tail length of less than , making them the smallest primates (the smallest spe ...
'' includes the smallest primates in the world.
Phylogenetic analyses In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...
of
D-loop In molecular biology, a displacement loop or D-loop is a DNA structure where the two strands of a double-stranded DNA molecule are separated for a stretch and held apart by a third strand of DNA. An R-loop is similar to a D-loop, but in this ca ...
DNA sequence DNA sequencing is the process of determining the nucleic acid sequence – the order of nucleotides in DNA. It includes any method or technology that is used to determine the order of the four bases: adenine, guanine, cytosine, and thymine. Th ...
s of various lemur species suggest that the gray mouse lemur may be most closely related to the
reddish-gray mouse lemur The reddish-gray mouse lemur (''Microcebus griseorufus'') also known as the gray-brown mouse lemur or rufous-gray mouse lemur, is a small, solitary-but-social, nocturnal and omnivorous primate from the Western Madagascar in the region around B ...
(''M. griseorufus''). First described in 1777 by English illustrator
John Frederick Miller John Frederick Miller (1759–1796) was an English illustrator, mainly of botanical subjects. Miller was the son of the artist Johann Sebastian Müller (1715 – c. 1790). Miller, along with his brother James, produced paintings from the sketches ...
, ''M. murinus'' remained the only species of its genus, as well as the name used for all mouse lemurs on Madagascar, between the first major taxonomic revision in 1931 and an extensive
field study Field research, field studies, or fieldwork is the collection of raw data outside a laboratory, library, or workplace setting. The approaches and methods used in field research vary across disciplines. For example, biologists who conduct fi ...
conducted in 1972. The field study distinguished the
brown mouse lemur The brown mouse lemur (''Microcebus rufus'') is a small primate, and like the other mouse lemurs can only be found on the island of Madagascar. They are known also as the rufous mouse lemur, eastern rufous mouse lemur, red mouse lemur, or russet ...
, ''M. rufus''—then considered a subspecies—as a distinct,
sympatric In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species sh ...
species in the southeastern part of the island. Upon this revision, the gray mouse lemur was thought to account for all mouse lemurs that lived in the drier parts of the north, west, and south, while the brown mouse lemur represented the eastern rainforest mouse lemurs. More recently, scientific understanding of the distribution and diversity of the mouse lemurs has become much more complex. Additional field studies, genetic testing, and resulting taxonomic revisions throughout the 1990s and 2000s identified numerous new mouse lemur species, demonstrating that the genus includes at least 17
cryptic species In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...
. *


Anatomy and physiology

The gray mouse lemur shares many traits with other mouse lemurs, including soft fur, a long tail, long hind limbs, a
dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal c ...
stripe down the back (not always distinct), a short snout, rounded skull, prominent eyes, and large, membranous, protruding ears. It has large eyes and a ''
tapetum lucidum The ''tapetum lucidum'' ( ; ; ) is a layer of tissue in the eye of many vertebrates and some other animals. Lying immediately behind the retina, it is a retroreflector. It reflects visible light back through the retina, increasing the light a ...
'' to enhance its vision at night. The dorsal coat is brownish-gray with various reddish tones, the flanks are light gray to beige, and the
ventral Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek language, Greek roots, describe something in its standard anatomical position. Th ...
fur has discrete dull beige or whitish-beige patches along portions of the belly. On the rounded face, there is a pale white patch above the nose and between the eyes; some individuals have dark orbital markings. The furred portions of the hands and feet are off-white. The gray mouse lemur is one of the smallest primates in the world, yet it is also the largest mouse lemur. Its total length is , with a head-body length of and a
tail The tail is the section at the rear end of certain kinds of animals’ bodies; in general, the term refers to a distinct, flexible appendage to the torso. It is the part of the body that corresponds roughly to the sacrum and coccyx in mammals, r ...
length of . The average weight for this species is , with ranges of and reported. This is smaller than the world's smallest monkey, the
pygmy marmoset Pygmy marmosets are two species of small New World monkeys in the genus ''Cebuella''. They are native to rainforests of the western Amazon Basin in South America. These primates are notable for being the smallest monkeys in the world, at just ov ...
, which ranges between . Weight varies by season, with both sexes building fat reserves, up to 35% of their body weight, in the tail and hind legs prior to the dry season and periods of dormancy. The tail of the gray mouse lemur can increase fourfold in volume during the wet season when it is storing fat. Even in captivity when environmental limitations are not an issue, mouse lemurs have shown a seasonal dietary preference with a greater protein intake during what would be their more active season. Researchers have identified differences in the tooth morphology of the first and second molars between the gray mouse lemur and the reddish-gray mouse lemur. In the reddish-gray mouse lemur, the first lower molar (m1) is squared and both the first and second upper molars (M1 and M2) have slight indentations around the middle of the posterior margin. The gray mouse lemur has a more elongated m1 and lacks the aforementioned indentation on M1 and M2. In terms of its general
dentition Dentition pertains to the development of teeth and their arrangement in the mouth. In particular, it is the characteristic arrangement, kind, and number of teeth in a given species at a given age. That is, the number, type, and morpho-physiolo ...
, the gray mouse lemur shares the same dental formula as all other members of its family, Cheirogaleidae: This species has 66
chromosome A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are ...
s, closely resembling the
karyotype A karyotype is the general appearance of the complete set of metaphase chromosomes in the cells of a species or in an individual organism, mainly including their sizes, numbers, and shapes. Karyotyping is the process by which a karyotype is disce ...
of the dwarf lemurs (genus ''Cheirogaleus''). Except for the
X chromosome The X chromosome is one of the two sex-determining chromosomes (allosomes) in many organisms, including mammals (the other is the Y chromosome), and is found in both males and females. It is a part of the XY sex-determination system and XO sex-d ...
, all chromosomes are
acrocentric The centromere links a pair of sister chromatids together during cell division. This constricted region of chromosome connects the sister chromatids, creating a short arm (p) and a long arm (q) on the chromatids. During mitosis, spindle fibers ...
(with the short arm absent or virtually absent). Its
genome size Genome size is the total amount of DNA contained within one copy of a single complete genome. It is typically measured in terms of mass in picograms (trillionths (10−12) of a gram, abbreviated pg) or less frequently in daltons, or as the total ...
is 3.12 picograms (pg).


Ecology

Like all other members of the
family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
Cheirogaleidae The Cheirogaleidae are the family of strepsirrhine primates containing the various dwarf and mouse lemurs. Like all other lemurs, cheirogaleids live exclusively on the island of Madagascar. Characteristics Cheirogaleids are smaller than the ...
, the gray mouse lemur is nocturnal and
arboreal Arboreal locomotion is the Animal locomotion, locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. Th ...
. It inhabits lowland tropical dry forest, sub-arid thorn scrub,
gallery forest A gallery forest is one formed as a corridor along rivers or wetlands, projecting into landscapes that are otherwise only sparsely treed such as savannas, grasslands, or deserts. The gallery forest maintains a more temperate microclimate above th ...
, spiny forest, eastern
littoral The littoral zone or nearshore is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely inundated), to coastal areas ...
forest,
dry deciduous forest The tropical and subtropical dry broadleaf forest is a habitat type defined by the World Wide Fund for Nature and is located at tropical and subtropical latitudes. Though these forests occur in climates that are warm year-round, and may receive ...
s, semi-humid deciduous, moist lowland forest, transitional forest, and
secondary forest A secondary forest (or second-growth forest) is a forest or woodland area which has re-grown after a timber harvest or clearing for agriculture, until a long enough period has passed so that the effects of the disturbance are no longer evident. ...
s or degraded forests (including plantations) all ranging up to above sea level. The species is more common in secondary forest than in primary forest, particularly bush and scrub habitat, where it occupies a "fine branch"
niche Niche may refer to: Science *Developmental niche, a concept for understanding the cultural context of child development *Ecological niche, a term describing the relational position of an organism's species *Niche differentiation, in ecology, the ...
, restricting the vertical range to fine branches, fine terminal supports,
liana A liana is a long- stemmed, woody vine that is rooted in the soil at ground level and uses trees, as well as other means of vertical support, to climb up to the canopy in search of direct sunlight. The word ''liana'' does not refer to a ta ...
s and dense foliage. These lemurs are usually seen on branches less than in diameter. The gray mouse lemur tends to prefer lower levels of the forest and the
understory In forestry and ecology, understory (American English), or understorey (Commonwealth English), also known as underbrush or undergrowth, includes plant life growing beneath the forest canopy without penetrating it to any great extent, but abov ...
, where branches and vegetation are dense. In secondary forest, it is generally observed from ground level up to above ground, yet in the
canopy Canopy may refer to: Plants * Canopy (biology), aboveground portion of plant community or crop (including forests) * Canopy (grape), aboveground portion of grapes Religion and ceremonies * Baldachin or canopy of state, typically placed over an ...
of
primary forest An old-growth forestalso termed primary forest, virgin forest, late seral forest, primeval forest, or first-growth forestis a forest that has attained great age without significant disturbance, and thereby exhibits unique ecological featur ...
. Studies have found that the species can spend as much as 40% of its time below , with 70% of its time spent at this level during the end of the dry season, when plant food is limited and insects compose a larger percentage of the diet. The species is more numerous in spiny forest, such as the Andohahela Special Reserve, than in the gallery forest, preferring drier, littoral forest, whereas the brown mouse lemur prefers inland rain forest. The limits of the distribution are poorly understood. It is believed to range from the Onilahy River or Lake Tsimanampetsotsa in the south to
Ankarafantsika National Park Ankarafantsika National Park is a national park near Andranofasika in the Boeny Region of Madagascar. The closest city is Majunga north of the park. Ankarafantsika is mostly tropical in climate type. The Sakalava people are the predominant ethn ...
in the north. There is also an isolated and disjointed population in the southeastern part of the island, near Tôlanaro and the Andohahela National Park, up to the Mandena Conservation Zone. Individuals tend to occupy small
home range A home range is the area in which an animal lives and moves on a periodic basis. It is related to the concept of an animal's territory which is the area that is actively defended. The concept of a home range was introduced by W. H. Burt in 1943. He ...
s of . The gray mouse lemur is also
sympatric In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species sh ...
with the reddish-gray mouse lemur, golden-brown mouse lemur,
Madame Berthe's mouse lemur Madame Berthe's mouse lemur (''Microcebus berthae'') or Berthe's mouse lemur is the smallest of the mouse lemurs and the smallest primate in the world; the average body length is and seasonal weight is around . ''Microcebus berthae'' is one of ...
, and several other cheirogaleid lemurs. In
Ankarafantsika National Park Ankarafantsika National Park is a national park near Andranofasika in the Boeny Region of Madagascar. The closest city is Majunga north of the park. Ankarafantsika is mostly tropical in climate type. The Sakalava people are the predominant ethn ...
, where it coexists with the golden-brown mouse lemur, the gray mouse lemur's relative
population density Population density (in agriculture: standing stock or plant density) is a measurement of population per unit land area. It is mostly applied to humans, but sometimes to other living organisms too. It is a key geographical term.Matt RosenberPopul ...
was highest at higher altitudes and in drier habitat, while the golden-brown mouse lemur preferred the opposite. Another study has looked at the coexistence of the gray mouse lemur and Madame Berthe's mouse lemur and found small, exclusive clusters of each species and a high degree of feeding niche overlap. The gray mouse lemur can reach high population densities up to several hundred individuals per square kilometer (up to 167 individuals/km2 at Ankarafantsika National Park to 712 individuals/km2 at Kirindy Mitea National Park). This abundance is not uniform and tends to concentrate in "population nuclei", suggesting that it is difficult to accurately estimate population densities when extrapolating from a small area (from various studies) to a large area. The difficulty in finding individuals during some times of the year, particularly during the dry periods, can further complicate the problem of estimating population densities. Mouse lemurs are
omnivorous An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nutri ...
, and favor fruit and insects for the bulk of their diet. The gray mouse lemur may even come down to the ground to catch insect prey, though it quickly returns to the protective cover of the understory to consume its catch.
Nectar Nectar is a sugar-rich liquid produced by plants in glands called nectaries or nectarines, either within the flowers with which it attracts pollinating animals, or by extrafloral nectaries, which provide a nutrient source to animal mutualists ...
is also a part of the gray mouse lemur's diet, making it a potential
pollinator A pollinator is an animal that moves pollen from the male anther of a flower to the female stigma of a flower. This helps to bring about fertilization of the ovules in the flower by the male gametes from the pollen grains. Insects are the maj ...
for local plant species. A single instance of a male cannibalizing an adult female is known. *


Predation

The most significant
predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...
s of the gray mouse lemur are the
Madagascar owl The Madagascar owl (''Asio madagascariensis''), also known as the Madagascan owl or Madagascar long-eared owl, is a medium-sized owl endemic to the island of Madagascar. It is sometimes considered to be conspecific with the long-eared owl (''Asio ...
and barn owl. Studies conducted in
Beza Mahafaly Reserve The Beza Mahafaly Special Reserve is a nature reserve in Madagascar northeast of Betioky Sud. The reserve also provides training and research opportunities. It consists of a fenced gallery forest, approximately , separated by from a gallery of ...
and Kirindy Mitea National Park indicate a predation rate of around 25% (percent population taken by predators per year), the highest known for any primate species. However, given the species' high reproductive potential, predation does not appear to have a drastic effect on its populations. Other raptors, such as
Henst's goshawk Henst's goshawk (''Accipiter henstii'') is a species a bird of prey in the family Accipitridae. It is a large, diurnal bird endemic to the island of Madagascar. It is an obligate forest species that occurs at very low densities on the island and ...
and other owls, also prey upon this species.
Snake Snakes are elongated, Limbless vertebrate, limbless, carnivore, carnivorous reptiles of the suborder Serpentes . Like all other Squamata, squamates, snakes are ectothermic, amniote vertebrates covered in overlapping Scale (zoology), scales. Ma ...
s, such as '' Ithycyphus miniatus'' (a native
colubrid Colubridae (, commonly known as colubrids , from la, coluber, 'snake') is a family of snakes. With 249 genera, it is the largest snake family. The earliest species of the family date back to the Oligocene epoch. Colubrid snakes are found on ever ...
snake) and the
Madagascar tree boa ''Sanzinia madagascariensis'', also known as the Malagasy tree boaMehrtens JM. 1987. Living Snakes of the World in Color. New York: Sterling Publishers. 480 pp. . or Madagascar tree boa, is a boa species endemic to the island of Madagascar. It ...
, as well as mammalian predators, such as the
ring-tailed mongoose The ring-tailed vontsira, locally still known as the ring-tailed mongoose (''Galidia elegans'') is a euplerid in the subfamily Galidiinae, a carnivoran native to Madagascar. It is the only species in genus ''Galidia''. Classification and ety ...
, narrow-striped mongoose, fossa, and
domestic dog The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the wolf. Also called the domestic dog, it is Domestication of the dog, derived from the extinct Pleistocene wolf, and the modern wolf is the dog's n ...
s are also known to prey on the gray mouse lemur. Mammalian predators often discover tree holes serving as nests, and enlarge the opening so they can catch and eat the occupant. This puts strong
selective pressure Any cause that reduces or increases reproductive success in a portion of a population potentially exerts evolutionary pressure, selective pressure or selection pressure, driving natural selection. It is a quantitative description of the amount of ...
on the choice of nest hole opening diameter and deepness. Due to its non-gregarious nature, the gray mouse lemur, like other nocturnal lemurs, primarily defends itself from predators using avoidance strategies, although group defense through the use of
alarm call In animal communication, an alarm signal is an antipredator adaptation in the form of signals emitted by social animals in response to danger. Many primates and birds have elaborate alarm calls for warning conspecifics of approaching predators ...
s and predator mobbing has been observed in this species. Studies involving the placement of predator and non-predator
fecal Feces ( or faeces), known colloquially and in slang as poo and poop, are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the large intestine. Feces contain a relati ...
odor with captive populations have demonstrated a genetic predisposition for predator recognition through the detection of
metabolite In biochemistry, a metabolite is an intermediate or end product of metabolism. The term is usually used for small molecules. Metabolites have various functions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, c ...
s from meat digestion. The mouse lemurs were shown to avoid locations where they typically received rewards, as well as exhibit increased activity and anti-predator behavior, when the odor of predator feces were present in that vicinity, but not when the fecal odor of Malagasy non-predators was present. During the day, when they are most vulnerable, individuals shelter inside tree holes, sometimes forming nests. They may use three to nine different tree holes within their home range, yet individuals may use one particular hole for up to five consecutive days. Mouse lemurs tend to prefer tree hollows, but also commonly make spherical constructions out of leaves. Nests are usually found in tree holes with a minimum diameter of , with a
median In statistics and probability theory, the median is the value separating the higher half from the lower half of a data sample, a population, or a probability distribution. For a data set, it may be thought of as "the middle" value. The basic fe ...
of , suggesting that this range in diameter of tree holes may be crucial for maintaining a healthy habitat. The gray mouse lemur also spends most of its time in dense vegetation, limiting its visibility and accessibility to predators. Furthermore, it has a high reproductive rate to counter losses to predation.


Behavior

The gray mouse lemur is nocturnal, sleeping during the day in tree holes lined with leaf litter or purpose-built spherical nests constructed from dead leaves, moss and twigs. It usually forages alone at night, but may sleep in groups during the day, the composition of which depends on gender and season. Tree holes can be shared with up to 15 other individuals, although males tend to sleep alone while females tend to share nests. All mouse lemurs are highly active at night, often scurrying like mice and leaping over , using the tail as a balancing organ. When moving among the terminal branches of bushes and trees, they grip using all four feet and move with four legs. When on the ground, either to catch insects or cross short open areas, mouse lemurs hop like a frog. When hunting, the grey mouse lemur is known to catch invertebrates and small vertebrates with quick hand grasps. In the dry season, the gray mouse lemur faces the challenge of exploiting sparsely distributed feeding resources efficiently. Results of a recent study on this showed that the gray mouse lemur does not move around randomly, but rather use spatial cues to find food resources in the absence of sensory cues, and that they seem to reuse common, highly efficient routes with regard to travel distance. It is believed that rather than using a route-based network, the gray mouse lemur has some sense of
mental representation A mental representation (or cognitive representation), in philosophy of mind, cognitive psychology, neuroscience, and cognitive science, is a hypothetical internal cognitive symbol that represents external reality, or else a mental process that ma ...
of their spatial environment, which they use to find and exploit food resources. Foraging behavior is often slow, with height and direction changing continuously. Predation of insects occurs primarily on the ground. Before descending, the ear pinnae move alternately to help pinpoint the precise location of their prey. Insects are captured during a rapid dash across the leaf litter and are transported by mouth up into the relative safety of the branches. Studies with captive gray mouse lemurs have shown that vision is primarily used for prey detection, although the other senses certainly play a role in foraging. The gray mouse lemur is omnivorous, feeding primarily on fruit and
invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...
s. Local populations appear to specialize on locally available fruit. At both Marosalaza and Mandena,
beetle Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...
s are the primary insect prey, although moths, praying mantids, fulgorid bugs, crickets, cockroaches, and spiders are also eaten. Less than half the diet consists of insects, with fruit making up a slightly larger fraction. This lemur also consumes flowers, gums and nectar from ''
Euphorbia ''Euphorbia'' is a very large and diverse genus of flowering plants, commonly called spurge, in the family Euphorbiaceae. "Euphorbia" is sometimes used in ordinary English to collectively refer to all members of Euphorbiaceae (in deference to t ...
'' and ''
Terminalia Terminalia may refer to: * Terminalia (festival), a Roman festival to the god of boundaries Terminus * ''Terminalia'' (plant), a tree genus * Terminalia (insect anatomy), the terminal region of the abdomen in insects * ''Polyscias terminalia'', a ...
'' trees, leaves (''
Uapaca ''Uapaca'' is a genus of plant, in the family Phyllanthaceae first described as a genus in 1858. It is the only genus comprised in the tribe Uapaceae. The genus is native to Africa and Madagascar. ''Uapaca'' is dioecious, with male and female f ...
'' sp.),
exudate An exudate is a fluid emitted by an organism through pores or a wound, a process known as exuding or exudation. ''Exudate'' is derived from ''exude'' 'to ooze' from Latin ''exsūdāre'' 'to (ooze out) sweat' (''ex-'' 'out' and ''sūdāre'' 'to ...
s ( Homopteran larvae secretions), and small
vertebrate Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, ...
s such as
tree frog A tree frog (or treefrog) is any species of frog that spends a major portion of its lifespan in trees, known as an arboreal state. Several lineages of frogs among the Neobatrachia have given rise to treefrogs, although they are not closely rela ...
s,
gecko Geckos are small, mostly carnivorous lizards that have a wide distribution, found on every continent except Antarctica. Belonging to the infraorder Gekkota, geckos are found in warm climates throughout the world. They range from . Geckos ar ...
s, and
chameleon Chameleons or chamaeleons (family Chamaeleonidae) are a distinctive and highly specialized clade of Old World lizards with 202 species described as of June 2015. The members of this family are best known for their distinct range of colors, bein ...
s. Its diet is seasonally varied and diverse in content, giving it a very broad feeding niche compared to other species such as the Madame Berthe's mouse lemur. Therefore, it is affected more by food availability than by niche partitioning where sympatry occurs.


Dormancy

As with all members of the mouse lemur genus, the gray mouse lemur is known to enter short states of daily torpor, particularly during the cool, dry Southern Hemisphere winter. This rare trait in primates, coupled with the ease of observing the species within its wide geographic distribution and its good representation in captivity, makes it a popular subject for research as a
model organism A model organism (often shortened to model) is a non-human species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the model organism will provide insight into the workin ...
. The gray mouse lemur is unique among the mouse lemurs studied so far because it is the only species to exhibit prolonged seasonal torpor, but this behavior has only been observed to occur in one locality. Activity patterns can differ noticeably between sexes as well as populations. At the Ampijoroa Forestry Station in Ankarafantsika National Park, males and females exhibit daily, rather than seasonal torpor. At Kirindy Forest, both sexes share the same daily torpor, yet during the dry season (April/May through September/October), females become completely inactive for several weeks or up to five months to conserve energy and reduce predation. However, males rarely remain inactive for more than a few days and become extremely active before the females revive from torpor, allowing them to establish hierarchies and
territories A territory is an area of land, sea, or space, particularly belonging or connected to a country, person, or animal. In international politics, a territory is usually either the total area from which a state may extract power resources or a ...
for the
breeding season Seasonal breeders are animal species that successfully mate only during certain times of the year. These times of year allow for the optimization of survival of young due to factors such as ambient temperature, food and water availability, and cha ...
. The use of alternative energy-saving strategies under the same environmental conditions was observed directly in 2008, providing the first physiological confirmation from the field. This pattern of seasonal versus daily torpor may relate to the seasonality of the region, since Kirindy is the only location west of the eastern mountain rainforests that experiences very low temperatures at night during the winter months. By entering extended torpor, sometimes referred to as hibernation, this would reduce the thermoregulatory stress in females, whereas males remain more active in preparation for the upcoming mating season. No difference in mortality has been shown between hibernating females and active males. During torpor, the gray mouse lemur's metabolic rate slows and its body temperature drops to the ambient temperature, as low as . During the cooler months of May though August, the species selects tree holes closer to ground level, where ambient temperatures remain more stable. This allows them to remain in torpor longer, and to conserve metabolic resources. One study showed that during the breeding season, both males and females reduced their energy expenditure by 20% when they nested in pairs, and a maximal energetic benefit of 40% was achieved when three mouse lemurs nested together. Even during the nonbreeding season, maximal energetic gain was observed two or more animals nested together, because resting metabolic rate was already decreased. While the gray mouse lemur is found in both primary and secondary deciduous forests, they have lower population densities in secondary forests. This is because variations in gray mouse lemur abundance are linked to their capacity to enter torpor during the dry season, especially for females, which tend to hibernate longer than males. In primary forests, they can maintain daily torpor or hibernation as long as their body temperatures remain below , but in secondary forests that have fewer large trees, temperatures are higher and inhibit the gray mouse lemur's ability to maintain torpor for prolonged periods of time. In addition, the gray mouse lemur in secondary forests tend to have a lower body mass than those in primary forests, as well as lower survival rates. This is likely because those with lower body mass are less likely to enter torpor, and therefore expend around 40% more energy than those that do maintain torpor. This unusual ability for a primate to exhibit dormancy, in addition to the diminutive size, has led researchers to speculate that ancestral lemurs, and possibly ancestral primates, may have shared some traits with mouse lemurs. Consequently, the gray mouse lemur has once again been used as a model organism for studying lemur and primate evolution. For example, lemurs are thought to have colonized Madagascar by
rafting Rafting and whitewater rafting are recreational outdoor activities which use an inflatable raft to navigate a river or other body of water. This is often done on whitewater or different degrees of rough water. Dealing with risk is often a ...
to the island around 60 million years ago according to
molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...
studies.Mittermeier, R.A.; et al. (2006) "Chapter 1: Origin of the lemurs", pp. 23–26 Before the discovery that ocean currents were the opposite of what they are today, thus favoring such an event, * it was thought that it would have taken too long for any animal not capable of entering a state of dormancy to survive the trip. Therefore, the mouse lemurs, such as the gray mouse lemur, were thought to have shared this
plesiomorphic In phylogenetics, a plesiomorphy ("near form") and symplesiomorphy are synonyms for an ancestral character shared by all members of a clade, which does not distinguish the clade from other clades. Plesiomorphy, symplesiomorphy, apomorphy, and ...
(ancestral) trait with the ancestral lemurs.


Social systems

The gray mouse lemur is described as
solitary but social Sociality is the degree to which individuals in an animal population tend to associate in social groups (gregariousness) and form cooperative societies. Sociality is a survival response to evolutionary pressures. For example, when a mother wasp ...
, foraging alone at night, but frequently sleeping in groups during the day. This social pattern varies by gender, season, and location. Females tend to share nests with other females and their offspring, whereas males tend to sleep alone or in pairs outside of the breeding season. Groups of females sharing a nest can be relatively stable, consisting of two to nine individuals, although a male may be found with a group of females outside the breeding season. During the breeding season (September through October), males and females may sleep in the same tree hole. Mixed sex groups can be common at this time, with single males sharing nest sites with three to seven females or single females sharing nest sites with one to three males. Research has shown that home ranges for the gray mouse lemur are usually small, possibly less than . Males typically travel further at night and have home ranges that are twice as large as those of females, often overlapping with one another, and always overlapping with at least one female's home range. Male home ranges increase threefold during the breeding season. Female home ranges overlap less than those of males, although localized concentrations, or "population nuclei", tend to form in some areas, where the sex ratio favors females to males by three or four to one at the nucleus core. Genetic studies indicate that females arrange themselves spatially in clusters ("population nuclei") of related individuals, while males tend to emigrate from their natal group. Research has shown that females in this species may maintain smaller ranges and associate more closely with other females than in some other mouse lemur species due to a more opportunistic feeding niche and, in the case of populations at Kirindy, the use of extended, seasonal torpor.


Communication

Vocalizations and
scent An odor (American English) or odour (Commonwealth English; see spelling differences) is caused by one or more volatilized chemical compounds that are generally found in low concentrations that humans and animals can perceive via their sense ...
are the primarily modes of communication within this species.
Home range A home range is the area in which an animal lives and moves on a periodic basis. It is related to the concept of an animal's territory which is the area that is actively defended. The concept of a home range was introduced by W. H. Burt in 1943. He ...
s are scent marked with urine and feces. Vocalizations are complex and very high-pitched (ranging from 10 to 36 
kHz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that on ...
), sometimes beyond the range of human hearing (0.02 to 20 kHz). These include calls for seeking contact, mating, distant communication, alarm, and distress. Like other mouse lemurs, the gray mouse lemur uses what has been described as a harmonic whistle call that is lower in frequency and shorter in duration than its close relative, the
brown mouse lemur The brown mouse lemur (''Microcebus rufus'') is a small primate, and like the other mouse lemurs can only be found on the island of Madagascar. They are known also as the rufous mouse lemur, eastern rufous mouse lemur, red mouse lemur, or russet ...
. In addition, it has been found that the types of vocalizations emitted by the gray mouse lemur can be dependent upon the environment. In the more open dry forest habitats favored by the gray mouse lemur, trill calls are more common and effective since they carry faster and are less likely to be masked by the wind, while chirp calls are more common in the brown mouse lemur, which favors closed rain forest habitats. As with other social mammals, the calls reveal the sex and identity of the individual. Dialects have also been detected between communities. The male trill call, part of the male mating display, is much like a
bird song Bird vocalization includes both bird calls and bird songs. In non-technical use, bird songs are the bird sounds that are melodious to the human ear. In ornithology and birding, songs (relatively complex vocalizations) are distinguished by func ...
in terms of its ordered sequence of broadband frequency modulated syllables, ranging between 13 and 35 kHz in pitch and lasting 0.3 to 0.9 seconds, repeating up to 1.5 times per minute. Each locality has its own theme of trill calls that is distinct from those of neighboring communities, and resident males produce individually distinct trill calls within that theme. These calls are not genetically programmed. During play, young males produce early attempts at the trill call, which show high degrees of variability. Research has shown that the male mouse lemurs consciously manipulate the dialect to resemble those of their neighbors, when transferred from their home to a new neighborhood. This may reduce aggression and foster social acceptance for emigrant males as they transfer from their natal group upon maturity. Because mouse lemurs are cryptic species, and therefore visually indistinguishable, their social calls help individuals select mates of their own species. This differentiated signaling and recognition system has promoted species cohesiveness through premating isolation, and helped researchers distinguish and identify species.


Breeding and reproduction

The
mating system A mating system is a way in which a group is structured in relation to sexual behaviour. The precise meaning depends upon the context. With respect to animals, the term describes which males and females mating, mate under which circumstances. Reco ...
is described as multi-male and multi-female. Males establish dominance hierarchies prior to the mating season, however, some studies in the wild have shown no male aggression or visible competition for receptive females. Males in captivity become highly aggressive and form strict dominance hierarchies. These captive males may show the highest
plasma Plasma or plasm may refer to: Science * Plasma (physics), one of the four fundamental states of matter * Plasma (mineral), a green translucent silica mineral * Quark–gluon plasma, a state of matter in quantum chromodynamics Biology * Blood pla ...
testosterone Testosterone is the primary sex hormone and anabolic steroid in males. In humans, testosterone plays a key role in the development of Male reproductive system, male reproductive tissues such as testes and prostate, as well as promoting secondar ...
levels found in mammals, and even the odor of a dominant male can lower the testosterone levels and sexually inhibit a subordinate male. During the breeding season, male
testes A testicle or testis (plural testes) is the male reproductive gland or gonad in all bilaterians, including humans. It is homologous to the female ovary. The functions of the testes are to produce both sperm and androgens, primarily testoster ...
increase significantly in size, facilitating
sperm competition Sperm competition is the competitive process between spermatozoa of two or more different males to fertilize the same egg during sexual reproduction. Competition can occur when females have multiple potential mating partners. Greater choice and ...
due to
female promiscuity Promiscuity tends to be frowned upon by many societies that expect most members to have committed, long-term relationships. Among women, as well as men, inclination for sex outside committed relationships is correlated with a high libido, but ev ...
. Studies with the gray mouse lemur have shown that the optimal insemination period, during which a male is most likely to sire offspring, occurs early during a female's receptivity. Only during the mating season does male mortality rise above that of female mortality. Although the gray mouse lemur displays multi-male, multi-female mating patterns, studies have shown that females do exhibit indirect mate selection (a form of selected polyandry). During the study, females would mate with 1–7 males up to 11 times during their single night of receptivity, but would avoid or counteract males that attempted to monopolize mating. Dominant males that attempt to monopolize tend to be larger and heavier individuals. Female selection however, has been shown to help increase genetic diversity among offspring. The gray mouse lemur is considered overall sexually monomorphic, but seasonally fluctuating
sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...
in terms of body mass has been recorded. While the body mass of both sexes fluctuates over the year as a function of food availability, being highest in the rainy season, the differing behavioral repertoires of the sexes lead to sex-specific patterns in this fluctuation. For example, male body mass increases prior to the mating season due to a substantial increase in testes volume that likely enhances the males' success in sperm competition. The females are receptive for 45 to 55 days between September and October, with
estrus The estrous cycle (, originally ) is the set of recurring physiological changes that are induced by reproductive hormones in most mammalian therian females. Estrous cycles start after sexual maturity in females and are interrupted by anestrous p ...
lasting 1 to 5 days. Females advertise estrus by distinctive high-frequency calls and scent-marking. Gestation lasts 54 to 68 days, averaging 60 days, typically resulting in 2 or 3 offspring weighing each. Infants are born in a leaf nest or tree hole in November prior to the onset of the rainy season.
Weaning Weaning is the process of gradually introducing an infant human or another mammal to what will be its adult diet while withdrawing the supply of its mother's milk. The process takes place only in mammals, as only mammals produce milk. The infan ...
occurs after 25 days, and the infants are either left in the nest or carried in the mother's mouth and deposited on a branch while she forages. Infant mouse lemurs do not cling to the mother's fur. Independence is attained in 2 months, while sexual maturity is reached at 10 to 29 months in females and 7 to 19 months in males. Closely related females remain loosely associated after maturation (female
philopatry Philopatry is the tendency of an organism to stay in or habitually return to a particular area. The causes of philopatry are numerous, but natal philopatry, where animals return to their birthplace to breed, may be the most common. The term derives ...
), whereas males disperse from their natal area. In the wild, the gray mouse lemur's reproductive lifespan is no more than 5 years, although captive specimens have reportedly lived as long as 15 years and 5 months, or even as long as 18.2 years. The gray mouse lemur uses cooperative breeding as a form of family insurance. The female regularly transfers her offspring to other females' nests—and likewise grooms and cares for offspring other than her own. While this can have a high physiological cost on a lactating female that is already expending a lot of energy, it can be beneficial overall to insuring survival among closely related groups with high mortality risk. A study that took place over three breeding seasons showed that closely related females form breeding groups mainly when there is a shortage of suitable roosts; when there is an advantage of a communal nest for defense, or when there are thermoregulatory benefits. In the event of offspring adoption, when a parent dies and a closely related female takes over care, it is believed that this is beneficial to groups with high mortality risk.


Conservation status

The gray mouse lemur was listed in Appendix 1 by the
Convention on International Trade in Endangered Species CITES (shorter name for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of interna ...
(CITES) in 1975, declaring it as threatened with extinction and prohibiting international trade of specimens except for non-commercial use, such as scientific research. The 2008
International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...
(IUCN) Red List assessment lists it as a species of
least concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...
(LC) with a decreasing population trend. Its greatest threats are habitat loss from
slash-and-burn agriculture Slash-and-burn agriculture is a farming method that involves the cutting and burning of plants in a forest or woodland to create a field called a swidden. The method begins by cutting down the trees and woody plants in an area. The downed veget ...
and cattle-
grazing In agriculture, grazing is a method of animal husbandry whereby domestic livestock are allowed outdoors to roam around and consume wild vegetations in order to convert the otherwise indigestible (by human gut) cellulose within grass and other ...
, as well as live capture for the local pet trade in the northern and southern parts of its range. Although this species inhabits secondary forests, studies have shown that decreased habitat quality adversely affects its populations since fewer tree holes offer fewer opportunities to conserve energy, increasing stress and mortality. One study found nine species of parasites in the fecal matter of the gray mouse lemur living in forests that suffered degradation and fragmentation. In small fragments of good quality forest, as well as forests with high levels of degradation, the gray mouse lemur showed a higher prevalence of parasitic nematodes and protozoans than those in larger good quality forest fragments. Studies in the late 1960s and 1970s showed that heavy logging between 1968 and 1970 seemed to result in decreased body weight, the use of smaller trees for nesting sites, and a smaller maximum female nesting group size (down to 7 from 15). There is also a concern that although daily torpor can help conserve energy and resources during moderate food shortages, extended food shortages brought about by
climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...
could create too much stress and severely impact the survivability of the species. The gray mouse lemur is considered one of Madagascar's most abundant small native mammals, found in seven national parks, five special reserves, the Berenty Private Reserve, and other privately protected forests within the Mandena Conservation Zone. This species of mouse lemur breeds very well in captivity, although it is not commonly displayed in zoos like some larger, diurnal lemurs. In 1989, more than 370 individuals were housed by 14
International Species Information System Species360 (formerly International Species Information System or ISIS) founded in 1974, is an international non-profit organization that maintains an online database of wild animals under human care. , the organization serves more than 1,000 zoos ...
(ISIS) and non-ISIS institutions across the United States and Europe, 97% of which were captive born. In March 2009, 167 were registered at 29 ISIS institutions, including the
Duke Lemur Center The Duke Lemur Center is an sanctuary for rare and endangered strepsirrhine primates, located at Duke University in Durham, North Carolina. It is the largest sanctuary for strepsirrhine primates in the world. The center is open to the public ...
.


Notes


References

*


External links

*View th
Mouse lemur genome
in
Ensembl Ensembl genome database project is a scientific project at the European Bioinformatics Institute, which provides a centralized resource for geneticists, molecular biologists and other researchers studying the genomes of our own species and other v ...
. * {{Taxonbar, from=Q876491 Mouse lemurs Mammals described in 1777 Taxa named by John Frederick Miller