|Family:|| Daubentoniidae |
|Genus:|| Daubentonia |
É. Geoffroy, 1795
|D. madagascariensis distribution|
The aye-aye (Daubentonia madagascariensis) is a long-fingered lemur, a strepsirrhine primate native to Madagascar with rodent-like teeth that perpetually growand a special thin middle finger.
It is the world's largest nocturnal primate.It is characterized by its unusual method of finding food: it taps on trees to find grubs, then gnaws holes in the wood using its forward-slanting incisors to create a small hole in which it inserts its narrow middle finger to pull the grubs out. This foraging method is called percussive foraging, and takes up 5–41% of foraging time. The only other animal species known to find food in this way is the striped possum. From an ecological point of view, the aye-aye fills the niche of a woodpecker, as it is capable of penetrating wood to extract the invertebrates within.
The aye-aye is the only extant member of the genus Daubentonia and family Daubentoniidae. It is currently classified as Endangered by the IUCN; and a second species, Daubentonia robusta , appears to have become extinct at some point within the last 1000 years.
The genus Daubentonia was named after the French naturalist Louis-Jean-Marie Daubenton by his student, Étienne Geoffroy Saint-Hilaire, in 1795. Initially, Geoffroy considered using the Greek name Scolecophagus ("worm-eater") in reference to its eating habits, but he decided against it because he was uncertain about the aye-aye's habits and whether other related species might eventually be discovered.In 1863, British zoologist John Edward Gray coined the family name Daubentoniidae.
The French naturalist Pierre Sonnerat was the first to use the vernacular name "aye-aye" in 1782 when he described and illustrated the lemur, though it was also called the "long-fingered lemur" by English zoologist George Shaw in 1800—a name that did not stick. According to Sonnerat, the name "aye-aye" was a "cri d'exclamation & d'étonnement" (cry of exclamation and astonishment). However, American paleoanthropologist Ian Tattersall noted in 1982 that the name resembles the Malagasy name "hai hai" or "hay hay", which refers to the animal and is used around the island. According to Dunkel et al. (2012), the widespread use of the Malagasy name indicates that the name could not have come from Sonnerat. Another hypothesis proposed by Simons and Meyers (2001) is that it derives from "heh heh", which is Malagasy for "I don't know". If correct, then the name might have originated from Malagasy people saying "heh heh" to avoid saying the name of a feared, magical animal.
Due to its derived morphological features, the classification of the aye-aye was debated following its discovery. The possession of continually growing incisors (front teeth) parallels those of rodents, leading early naturalists to mistakenly classify the aye-aye within the mammalian order Rodentiaand as a squirrel, due to its toes, hair coloring, and tail. However, the aye-aye is also similar to felines in its head shape, eyes, ears and nostrils.
The aye-aye's classification with the order Primates has been just as uncertain. It has been considered a highly derived member of the family Indridae, a basal branch of the strepsirrhine suborder, and of indeterminate relation to all living primates.In 1931, Anthony and Coupin classified the aye-aye under infraorder Chiromyiformes, a sister group to the other strepsirrhines. Colin Groves upheld this classification in 2005 because he was not entirely convinced the aye-aye formed a clade with the rest of the Malagasy lemurs.
However, molecular results have consistently placed Daubentonia as the most basal of lemurs.The most parsimonious explanation for this is that all lemurs are derived from a single ancestor that rafted from Africa to Madagascar during the Paleogene. Similarities in dentition between aye-ayes and several African primate fossils ( Plesiopithecus and Propotto ) have led to the alternate theory that the ancestors of aye-ayes colonized Madagascar separately from other lemurs. In 2008, Russell Mittermeier, Colin Groves, and others ignored addressing higher-level taxonomy by defining lemurs as monophyletic and containing five living families, including Daubentoniidae.
Further evidence indicating that the aye-aye belongs in the superfamily Lemuroidea can be inferred from the presence of petrosal bullae encasing the ossicles of the ear.The aye-ayes are also similar to lemurs in their shorter back legs.
A full-grown aye-aye is typically about 90 centimetres (3 feet) long with a tail longer than its body. The species has an average head and body length of 36–43 cm (14–17 in) plus a tail of 56–61 cm (22–24 in), and weighs around 2 kilograms (4 pounds).
Young aye-ayes typically are silver colored on their front and have a stripe down their back. However, as the aye-ayes begin to reach maturity, their bodies will be completely covered in thick fur and are typically not one solid color. On the head and back, the ends of the hair are typically tipped with white while the rest of the body will ordinarily be a yellow and/or brown color.
Among the aye-aye's signature traits are its fingers.The third finger, which is much thinner than the others, is used for tapping, while the fourth finger, the longest, is used for pulling grubs and insects out of trees, using the hooked nail. The skinny middle finger is unique in the animal kingdom in that it possesses a ball-and-socket metacarpophalangeal joint. The aye-aye has also evolved a sixth digit, a pseudothumb, to aid in gripping.
The complex geometry of ridges on the inner surface of aye-aye ears helps to sharply focus not only echolocation signals from the tapping of its finger, but also to passively listen for any other sound produced by the prey. These ridges can be regarded as the acoustic equivalent of a Fresnel lens, and may be seen in a large variety of unrelated animals, such as lesser galago, bat-eared fox, mouse lemur, and others.
Females have two nipples located in the region of the groin.
The aye-aye is a nocturnal and arboreal animal meaning that it spends most of its life high in the trees. Although they are known to come down to the ground on occasion, aye-ayes sleep, eat, travel and mate in the trees and are most commonly found close to the canopy where there is plenty of cover from the dense foliage. During the day, aye-ayes sleep in spherical nests in the forks of tree branches that are constructed out of leaves, branches and vines before emerging after dark to begin their hunt for food. Aye-aye are solitary animals that mark their large home range with scent. The smaller territories of females often overlap those of at least a couple of males. Male aye-ayes tend to share their territories with other males and are even known to share the same nests (although not at the same time), and can seemingly tolerate each other until they hear the call of a female that is looking for a mate.
The aye-aye is an omnivore and commonly eats seeds, fruits, nectar and fungi, but also insect larvae and honey. 4 km (2+1⁄2 mi) a night.Aye-ayes tap on the trunks and branches of trees at a rate of up to eight times per second, and listen to the echo produced to find hollow chambers. Studies have suggested that the acoustic properties associated with the foraging cavity have no effect on excavation behavior. Once a chamber is found, they chew a hole into the wood and get grubs out of that hole with their highly adapted narrow and bony middle fingers. The aye-aye begins foraging between 30 minutes before and three hours after sunset. Up to 80% of the night is spent foraging in the canopy, separated by occasional rest periods. It climbs trees by making successive vertical leaps, much like a squirrel. Horizontal movement is more difficult, but the aye-aye rarely descends to jump to another tree, and can often travel up to
Though foraging is usually solitary, they occasionally forage in groups. Individual movements within the group are coordinated using both vocalisations and scent signals.
The aye-aye is classically considered 'solitary' as they have not been observed to groom each other.[ citation needed ] However, recent research suggests that it is more social than once thought. It usually sticks to foraging in its own personal home range, or territory. The home ranges of males often overlap, and the males can be very social with each other. Female home ranges never overlap, though a male's home range often overlaps that of several females. The male aye-ayes live in large areas up to 32 hectares (80 acres), while females have smaller living spaces that goes up to 8.1 hectares (20 acres). It is difficult for the males to defend a singular female because of the large home range. They are seen exhibiting polygyny because of this. Regular scent marking with their cheeks and neck is how aye-ayes let others know of their presence and repel intruders from their territory.
Like many other prosimians, the female aye-aye is dominant to the male. They are not typically monogamous, and will often challenge each other for mates. Male aye-ayes are very assertive in this way, and sometimes even pull other males away from a female during mating. Males are normally locked to females during mating in sessions that may last up to an hour. Outside of mating, males and females interact only occasionally, usually while foraging.The aye-aye is thought to be the only primate which uses echolocation to find its prey.
The aye-aye lives primarily on the east coast of Madagascar. Its natural habitat is rainforest or deciduous forest, but many live in cultivated areas due to deforestation. Rainforest aye-ayes, the most common, dwell in canopy areas, and are usually sighted above 70 meters altitude. They sleep during the day in nests built from interwoven twigs and dead leaves up in the canopy among the vines and branches.
The aye-aye was thought to be extinct in 1933, but was rediscovered in 1957. Nine individuals were transported to Nosy Mangabe, an island near Maroantsetra off eastern Madagascar, in 1966.Recent research shows the aye-aye is more widespread than was previously thought, but its conservation status was changed to endangered in 2014. This is for three main reasons: the aye-aye is considered evil, the forests of Madagascar are being destroyed, and the farmers will kill aye-ayes to protect their crops and for poaching. However, there is no direct evidence to suggest aye-ayes pose any legitimate threat to crops and therefore are killed based on superstition.
As many as 50 aye-ayes can be found in zoological facilities worldwide.
The aye-aye is often viewed as a harbinger of evil and killed on sight. Others believe, if one points its narrowest finger at someone, they are marked for death. Some say that the appearance of an aye-aye in a village predicts the death of a villager, and the only way to prevent this is to kill it. The Sakalava people go so far as to claim aye-ayes sneak into houses through the thatched roofs and murder the sleeping occupants by using their middle fingers to puncture their victims' aorta.
The conservation of this species has been aided by captive breeding, primarily at the Duke Lemur Center in Durham, North Carolina. This center has been influential in keeping, researching and breeding aye-ayes and other lemurs. They have sent multiple teams to capture lemurs in Madagascar and have since created captive breeding groups for their lemurs. Specifically, they were responsible for the first aye-aye born into captivity and studied how he and the other aye-aye infants born at the center develop through infancy. They have also revolutionized the understanding of the aye-aye diet.
The indri, also called the babakoto, is one of the largest living lemurs, with a head-and-body length of about 64–72 cm (25–28 in) and a weight of between 6 to 9.5 kg. It has a black and white coat and maintains an upright posture when climbing or clinging. It is monogamous and lives in small family groups, moving through the canopy, and is purely herbivorous, feeding mainly on leaves but also seeds, fruits, and flowers. The groups are quite vocal, communicating with other groups by singing, roaring and other vocalisations.
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. Collectively they are referred to as strepsirrhines. Also belonging to the suborder are the extinct adapiform primates which thrived during the Eocene in Europe, North America, and Asia, but disappeared from most of the Northern Hemisphere as the climate cooled. Adapiforms are sometimes referred to as being "lemur-like", although the diversity of both lemurs and adapiforms does not support this comparison.
Lemurs are mammals of the order Primates, divided into 8 families and consisting of 15 genera and around 100 existing species. They are native only to the island of Madagascar. Most existing lemurs are small, have a pointed snout, large eyes, and a long tail. They chiefly live in trees (arboreal), and are active at night (nocturnal).
The ring-tailed lemur is a large strepsirrhine primate and the most recognized lemur due to its long, black and white ringed tail. It belongs to Lemuridae, one of five lemur families, and is the only member of the Lemur genus. Like all lemurs it is endemic to the island of Madagascar. Known locally in Malagasy as maky or hira, it inhabits gallery forests to spiny scrub in the southern regions of the island. It is omnivorous and the most terrestrial of extant lemurs. The animal is diurnal, being active exclusively in daylight hours.
The gray mouse lemur, grey mouse lemur or lesser mouse lemur, is a small lemur, a type of strepsirrhine primate, found only on the island of Madagascar. Weighing 58 to 67 grams, it is the largest of the mouse lemurs, a group that includes the smallest primates in the world. The species is named for its mouse-like size and coloration and is known locally as tsidy, koitsiky, titilivaha, pondiky, and vakiandry. The gray mouse lemur and all other mouse lemurs are considered cryptic species, 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.
Chiromyiformes is an order of strepsirrhine primates that includes the aye-aye from Madagascar and its extinct relatives.
The ruffed lemurs of the genus Varecia are strepsirrhine primates and the largest extant lemurs within the family Lemuridae. Like all living lemurs, they are found only on the island of Madagascar. Formerly considered to be a monotypic genus, two species are now recognized: the black-and-white ruffed lemur, with its three subspecies, and the red ruffed lemur.
The giant mouse lemurs are members of the strepsirrhine primate genus Mirza. Two species have been formally described; the northern giant mouse lemur and Coquerel's giant mouse lemur. Like all other lemurs, they are native to Madagascar, where they are found in the western dry deciduous forests and further to the north in the Sambirano Valley and Sahamalaza Peninsula. First described in 1867 as a single species, they were grouped with mouse lemurs and dwarf lemurs. In 1870, British zoologist John Edward Gray assigned them to their own genus, Mirza. The classification was not widely accepted until the 1990s, which followed the revival of the genus by American paleoanthropologist Ian Tattersall in 1982. In 2005, the northern population was declared a new species, and in 2010, the World Wide Fund for Nature announced that a southwestern population might also be a new species.
Megaladapis, informally known as the koala lemur, is an extinct genus belonging to the family Megaladapidae, consisting of three extinct species of lemurs that once inhabited the island of Madagascar. The largest measured between 1.3 to 1.5 m in length.
Plesiorycteropus, also known as the bibymalagasy or Malagasy aardvark, is a recently extinct eutherian mammalian genus from Madagascar. Upon its description in 1895, it was classified with the aardvark, but more recent molecular evidence instead suggests that it is most closely related to the tenrecs. Two species are currently recognized, the larger P. madagascariensis and the smaller P. germainepetterae. They probably overlapped in distribution, as subfossil remains of both species have been found in the same site.
Fork-marked lemurs or fork-crowned lemurs are 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 the island. They are named for the two black stripes which run up from the eyes, converge on the top of the head, and run down the back as a single black stripe. They were originally placed in the genus Lemur in 1839, later moved between the genera Cheirogaleus and Microcebus, and given their own genus in 1870 by John Edward Gray. Only one species was recognized, until three subspecies described in 1991 were promoted to species status in 2001. New species may yet be identified, particularly in northeast Madagascar.
The collared brown lemur, also known as the red-collared brown lemur or red-collared lemur, is a medium-sized strepsirrhine primate and one of twelve species of brown lemur in the family Lemuridae. It is only found in south-eastern Madagascar. Like most species of lemur, it is arboreal, moving quadrupedally and occasionally leaping from tree to tree. Like other brown lemurs, this species is cathemeral, lives in social groups, primarily eats fruit, exhibits sexual dichromatism, and does not demonstrate female dominance. The species is listed as Endangered by the International Union for Conservation of Nature (IUCN) and is threatened primarily by habitat loss.
Archaeolemur is an extinct genus of lemurs that includes two species, Archaeolemur edwardsi and A. majori.
Lemurs, primates belonging to the suborder Strepsirrhini which branched off from other primates less than 63 million years ago, evolved on the island of Madagascar, for at least 40 million years. They share some traits with the most basal primates, and thus are often confused as being ancestral to modern monkeys, apes, and humans. Instead, they merely resemble ancestral primates.
Lemurs of Madagascar is a 2010 reference work and field guide for the lemurs of Madagascar, giving descriptions and biogeographic data for the known species. The primary contributor is Russell Mittermeier, president of Conservation International, and the cover art and illustrations were drawn by Stephen D. Nash. Currently in its third edition, the book provides details about all known lemur species, general information about lemurs and their history, and also helps travelers identify species they may encounter. Four related pocket field guides have also been released, containing color illustrations of each species, miniature range maps, and species checklists.
Subfossil lemurs are lemurs from Madagascar that are represented by recent (subfossil) remains dating from nearly 26,000 years ago to approximately 560 years ago. They include both extant and extinct species, although the term more frequently refers to the extinct giant lemurs. The diversity of subfossil lemur communities was greater than that of present-day lemur communities, ranging from as high as 20 or more species per location, compared with 10 to 12 species today. Extinct species are estimated to have ranged in size from slightly over 10 kg (22 lb) to roughly 160 kg (350 lb). Even the subfossil remains of living species are larger and more robust than the skeletal remains of modern specimens. The subfossil sites found around most of the island demonstrate that most giant lemurs had wide distributions and that ranges of living species have contracted significantly since the arrival of humans.
Milne-Edwards's sifaka, or Milne-Edwards's simpona, is a large arboreal, diurnal lemur endemic to the eastern coastal rainforest of Madagascar. Milne-Edwards's sifaka is characterized by a black body with a light-colored "saddle" on the lower part of its back. It is closely related to the diademed sifaka, and was until recently considered a subspecies of it. Like all sifakas, it is a primate in the family Indriidae.
Lemurs were first classified in 1758 by Carl Linnaeus, and the taxonomy remains controversial today, with approximately 70 to 100 species and subspecies recognized, depending on how the term "species" is defined. Having undergone their own independent evolution on Madagascar, lemurs have diversified to fill many ecological niches normally filled by other types of mammals. They include the smallest primates in the world, and once included some of the largest. Since the arrival of humans approximately 2,000 years ago, lemurs have become restricted to 10% of the island, or approximately 60,000 square kilometers (23,000 sq mi), and many face extinction. Concerns over lemur conservation have affected lemur taxonomy, since distinct species receive increased conservation attention compared to subspecies.
Plesiopithecus is an extinct genus of early strepsirrhine primate from the late Eocene.
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