Microcebus murinus	Indri indri (after a drawing by John Fleagle)

 

Lemur              Eulemur              Varecia              Hapalemur              Lepilemur

Microcebus Mirza Cheirogaleus Allocebus Phaner

Indri Propithecus Avahi Daubentonia

Lemur (Diurnal, 1 species)

 Lemur catta is the ring-tailed lemur, easy to recognize with its long black and white striped tail and the black mask patterns on its white face.  The fur is a solid brownish gray on the back and white on the belly.  Adult ring-tailed lemurs are cat-sized.  They are partly arboreal and partly terrestrial, spending more time on the ground than do most other lemurs.  Their diet consists mainly of fruit with some leaves and occasionally insects.  They travel almost constantly during the day to find food, taking only a short rest at the hottest time of the day.  
Ring-tailed lemurs live in groups of 5-25 animals, in which the adult females are dominant over the males.  Females stay in the group into which they are born while males move away.  The females are responsible for defending their group's territory against neighboring groups, mostly by vocal exchanges but occasionally by physical fighting.  Both sexes also scent-mark their territory by rubbing the scent glands in their wrists and forearms on trees and branches.  Within a group, males and females have separate dominance hierarchies.  Males rub their long tails between their forearms to coat the tails with their scent, and then waft their tails at one another, presumably to intimidate rivals with the strength of their scent.  
Infants are born in September, early spring in Madagascar.  Single birth is typical.  An infant clings to its mother's belly for its first two weeks of life and then rides on her back until it grows too large.  Ring-tailed lemurs are sexually mature at 1 1/2 to 2 1/2 years of age.  

Eulemur (Diurnal, 5 species)

 Eulemur fulvus
 Eulemur mongoz
 Eulemur macaco
 Eulemur coronatus
 Eulemur rubriventer

Varecia (Diurnal, 1 species)

 Varecia variegata

Hapalemur (Crepuscular, 3 species)

 Hapalemurs are restricted to areas of the forest where bamboo is plentiful.  They sleep in bamboo thickets during the day, and they eat bamboo shoots and leaves more than any other food, although they enjoy insects as well.  All of their teeth except the molars have serrated cutting edges, to saw through tough bamboo stalks.  
Hapalemurs are brownish, orangish, or reddish gray.  They are most active at dawn and at dusk.  To forage, they leap quadrupedally from branch to branch inside their bamboo thicket or in the trees, and they can also run well on the ground.  They associate in groups of 3 to 5 animals.  Hapalemurs communicate within their family groups with a soft grunt, and communicate with distant groups by using a loud call which sounds rather like the quack of a duck.  One offspring per birth is typical.  The young is born in a nest in early summer and clings to its mother's fur as she forages.  
 Hapalemur griseus, or the gray gentle-lemur, possesses a scent gland on the inside of the wrist, presumably for communication with conspecifics by marking trees and branches after the fashion of L. catta.  A subspecies, H. griseus alaotrensis, can swim well.  
 Hapalemur simus, the broad-nosed gentle-lemur, lacks the scent gland inside the wrist.  Also, some groups of H. simus are reported to eat reeds exclusively rather than reeds and insects.  
 Hapalemur aureus is the golden bamboo lemur.

Lepilemur (Nocturnal, 1 species)

 Lepilemur mustelinus

Microcebus (Nocturnal, 3 species)

Members of the genus Microcebus are primitive in appearance and probably resemble their ancestors who rafted to Madagascar more than most other living lemurs do.  They are physically adapted to a nocturnal lifestyle, with large, mobile ears, a pointed nose, and large round eyes with a tapetum lucidum .  Adults weigh in at an average of only two ounces.  During the day, these little lemurs sleep in the trees in spherical nests made from leaves.  As many as fifteen females may share a nest, while males usually sleep alone or in pairs.  At night, they forage alone, running quadrupedally along fine branches, but they also come to the ground to catch insects among the fallen leaves, in which case they hop quadrupedally, rather like frogs.  In addition to insects they eat fruits and seeds, as well as sap, which they obtain by scraping trees with their dental combs .  Female mouse lemurs have priority over males for access to food.  They are preyed upon by owls, snakes, and carnivores, and endure the highest known predation rate of any primate.
 The activities of gray mouse lemurs are seasonably variable.  As winter ends and the days lengthen, males begin to chase and fight each other to determine dominance relationships.  By the time mating season occurs, in September (which is spring in Madagascar), these relationships are established and will last until the next winter.  The dominant males do most of the mating.  Births are usually twins or triplets; accordingly, females have two pairs of nipples.  Infants are carried in their mother's mouth and left in the nest when she goes out to forage.  They are weaned in the rainy summer season, when food is abundant.  During the rainy season, mouse lemurs build up fat reserves at the base of the tail.  These reserves are consumed during the dry season, when their activity slows, aggressive behavior ceases, and they may not leave their nests for days.  The infants grow up quickly and will probably mate the year after they are born.  The high reproductive rate is probably a response to the high predation rate.  
The three species are: Microcebus murinus, the gray mouse lemur; Microcebus rufus, the brown mouse lemur; and Microcebus myoxinus , the pygmy mouse lemur.  

Mirza (Nocturnal, 1 species)

 Mirza coquereli

Cheirogaleus (Nocturnal, 2 species)

 Cheirogaleus medius
 Cheirogaleus major

Allocebus (Nocturnal, 1 species)

 Allocebus trichotis

Phaner (Nocturnal, 1 species)

 Phaner furcifer

Indri (Diurnal, 1 species)

 Indri indri, also known as the indri, is the largest extant lemur, averaging between 13 and 16 pounds.  It is arboreal and moves through the trees by leaping from trunk to trunk with its torso always vertical, propelled by its long hind legs.  In the middle of a leap the indri swings its hind legs out to the front so that it lands feet first.  At rest, it typically clings to a trunk in a sort of squatting posture, ready for the next leap.  This method of locomotion is called vertical clinging and leaping, or just VCL.  Like all vertical clingers and leapers, the indri has a low intermembral index .  It also has a small thin vestigial membrane of skin stretching from the upper arm to the chest, in the same form as that of the flying squirrels but much smaller, and probably minimally functional in the modern indri.  
The diet of indris is quite varied, including leaves, fruits, flowers, and even small amounts of dirt, presumably for the minerals.  They have very short tails and silky black and white fur.  Their faces are much shorter than those of other lemurs
The indri was discovered in the late 18th century and was given its scientific name when native Malagasy people who were guiding a European biologist spotted one in the trees and began to point and whisper, "Indri!  Indri!"  The European dutifully wrote down "Indri indri" as the name of the animal.  Later is was discovered that the word "indri" in the Malagasy language means "Look!  Over there!"  

Propithecus (Diurnal, 2 species)

 Sifakas move much like indris, but spend more time on the ground.
 Propithecus verrauxi, Verrauxi's sifaka,   
 Propithecus diadema

Avahi (Diurnal, 1 species)

 Avahi laniger

Daubentonia (Nocturnal, 1 species)

 The aye-aye, or Daubentonia madagascariensis , was long thought to be extinct.  Not only is it extremely rare due to the cutting of its forest habitat, the long interval between births, and its reputation as an evil omen which drives people to shoot it on sight, it is also solitary and shy, and difficult to track, photograph, and study.  
The fur of the aye-aye is coarse, and dark brown or black with some whitish patches on the face.  The ears are large and hairless.  The incisors are much like rodent incisors: large, curved, and continuously growing.  The limbs, fingers, and toes are long and slender; the third finger on each hand is so slender as to appear deformed or diseased at first sight.  The fingers have secondarily pointed nails rather than the flat nails of most other primates.  
These unique physical adaptations add up to a rather unnerving, otherworldly appearance, but the aye-aye puts them all to good use.  Its diet is largely composed of insect larvae found enclosed in tree trunks and branches.  The aye-aye taps a log with its extra-slender third finger and listens for evidence of hollow cavities containing larvae.  Then it bites through the wood with its large incisors and inserts its third finger into the hole to retrieve the larva.  An aye-aye in captivity was once given a log in which several holes had been drilled by researchers; some of the holes were planted with larvae and others were not, and all of the holes were then filled.  The aye-aye first located all of the cavities containing larvae, chewed into them and ate the food, and then chewed into all the other cavities only after it had found all the larvae.  Apparently, then, an aye-aye can distinguish between a cavity containing a larva and an empty cavity.  The aye-aye also eats fruit, including fruits with tough husks that can not be broken into without large, continuously growing incisors.  
Aye-ayes are nocturnal.  During the day they sleep in nests which they make out of twigs and foliage.  At night they travel and forage both in the trees and on the ground.  They are solitary but not territorial.  They communicate with each other by vocalization and by scent marking with urine.  Infants are born singly and are kept in the nest while the mother forages, which is more characteristic of lorisids than of other lemurs.