Species Fact Profile: Aye-Aye (Daubentonia madagascarensis)

                                                            Aye-Aye

                                           Daubentonia madagascarensis (Gmelin, 1788

Range: Madagascar (primarily the east, but some populations in the north and west)

Habitat: Forests - Rainforest, Decidious, Mangrove, Dry Scrub

Diet: Fruits, Nuts, Plant Exudates, and Insects (especially beetle larvae)

Social Grouping:  Solitary

Reproduction: Mating in the wild has been observed October through February.  Females mate with multiple males, and males presumably mate with multiple females.  Female estrous cycle is 21-65 days, marked by the vulva changing from small and gray to large and red.  Mating can take up to 2.5 hours, done while hanging upside down from a tree branch. Gestation period is 152-172 days, with a single infant born from February to September.  There is usually an inter-birth interval of 2-3 years, probably due to the slow development of the infant and high levels of parental involvement.  Only the female cares for the young.  Infants weigh 90-140 grams and resemble adults except for their eyes, which are green, and their ears, which are floppy instead of erect.  First leave the nest at 8 weeks, begin to eat solid food at 20 weeks (but may attempt to suckle until 1-year-old), sexually mature at 2.5 years.

Lifespan: 20-25 Years

      Conservation Status: IUCN Endangered, CITES Appendix I, USFWS Endangered

• Body length 36-44 centimeters, with a long, bushy tail longer than the rest of the body (44-53 centimeters).  Body is relatively slender, but appears bulky due to thick fur.  The ears are large and triangular with complex ridges in the interior that help channel sounds.  The snout is short.  Adult weight 2500-2700 grams.  No significant sexual dimorphism, apart from males being on average slightly larger than females.   Female has a single pair of teats near the groin.   The world’s largest wholly nocturnal primate
• The teeth are chisel-like in the manner of a rodent and grow throughout the animal’s life (originally classified as a rodent) – half as many teeth as other lemur species, with a large gap between the incisors and molars. 
• The third digit of each hand is very long, slender, and flexible (can be folded over or under the hand), appearing almost skeletal.  Often carried curled inward or otherwise sheltered when the animal is climbing or walking.  An early name for this species which never fell into common usage was “long-fingered lemur.”  They also possess a sixth digit which serves as a pseudothumb for gripping branches
• Long, coarse coat is dark brown or black with a scattering of white guard hairs.  The fare and throat are pale grey.  The eyes are pale yellow or orange (tapetum lucidum to reflect light).  The nose is pink.  Juveniles have a silvery stripe down the back that darkens with age·         
• Males largely tolerant of one another outside of breeding.  Males have been observed pulling other males off of females in the act of breeding.  Females are dominant to males
• Nocturnal.  Most of the day spent sleeping in a nest of twigs and dead leaves in the upper canopy, sometimes shared but usually alone (different individuals may occupy the same nest at different times).  Sometimes forage in small groups.  Most active in the hours immediately after sunset.  Home ranges are marked through bite marks in tree bark.  Home ranges overlap, with male ranges being larger than those of females.  Largely arboreal, but sometimes come to the ground
• The third digit is used as a probe to pierce fruit skin and scoop out soft interiors, or to tap on wood in search of cavities which may shelter beetles.  Once a dead space is found, the aye-aye bites into it using its powerful incisors to access the insects.  Possible predation on amphibians.  Only primate to forage through echolocation. Can consume 240-340 kilocalories a day, slightly less in the cold season than in the rest of the year.  May travel up to 4 kilometers per night foraging
• Unknown to what extent they are predated.  Fossa ae believed to be a possible predator, as well as larger raptors and possibly snakes for young aye-aye
• Only living species of the genus; 1 extinct giant aye-aye, D. robusta, was discovered in 1990’s, estimated at 3-5 times the size of the living species.  Cause of extinction unknown.  Genus named after French zoologist Louis J.M. Daubenton, who first discovered the animal in 1780, species name for Madagascar
• Common name may be derived from their vocalization, hai-hai, made when startled or fleeing
• Thought to be extinct in the early twentieth century until rediscovered in 1957.  Primary threat is rapid loss of natural habitat
• Sometimes killed by native Malagasy, who may view it either as an agricultural pest (they will raid fruit plantations readily) or out of superstition, as it is seen as a bad omen.  It is traditionally considered a harbinger of evil – the belief holds that if it points its skeletal finger at you, then you will die.  Some people (Sakalava) even claim that the aye-aye directly kills its victims by stabbing them through the heart with the finger.
• One of the few depictions in western culture is the character “Maurice,” the councilor to ring-tailed lemur “King Julian” in the Dreamworks Madagascar movies