83-444: Species: The aye-aye ( Daubentonia madagascariensis ) is a long-fingered lemur , a strepsirrhine primate native to Madagascar with rodent -like teeth that perpetually grow and a special thin middle finger that they can use to catch grubs and larvae out of tree trunks. 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
166-413: A nostril and is used for picking one's nose and eating mucus ( mucophagy ) so harvested from inside the nose. 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
249-488: A prehensile tail , a trait found only in New World monkeys , particularly atelids , among primates. Lemurs also rely heavily on their sense of smell, a trait shared with most other mammals and early primates, but not with the visually oriented higher primates. This sense of smell is important in terms of marking territory as well as provide an indication of whether or not another lemur is a viable breeding partner. Lemurs are
332-493: A rhinarium (or "wet nose"); a fully functional vomeronasal organ , which detects pheromones ; a postorbital bar and the lack of postorbital closure (a wall of thin bone behind the eye); orbits (bony sockets that enclose the eye) that are not fully facing forward; left and right mandible (lower jaw) bones that are not fully fused; and a small brain-to-body mass ratio . Additional traits shared with other prosimian primates (strepsirrhine primates and tarsiers ) include
415-410: A bicornuate (two-horned) uterus and epitheliochorial placentation . Because their thumbs are only pseudo-opposable, making their movement less independent of the other fingers, their hands are less than perfect at grasping and manipulating objects. On their feet, they have a widely abducted hallux (first toe) which facilitates the grasping of tree limbs. A common misconception is that lemurs have
498-441: 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. Mating season extends throughout the year, with females typically starting to breed at the age of three or four. They give birth to one offspring every two to three years. During
581-452: A different ocean gyre , producing currents that ran counter to what they are today. The ocean currents were shown to be even stronger than today, which would have pushed a raft along faster, shortening the trip to 30 days or less—short enough for a small mammal to survive easily. As the continental plates drifted northward, the currents gradually changed, and by 20 mya the window for oceanic dispersal had closed, effectively isolating
664-479: A diverse group of primates in terms of morphology and physiology. Some lemurs, such as the sportive lemurs and indriids , have longer hind limbs than forelimbs , making them excellent leapers . Indriids also have a specialized digestive system for folivory , exhibiting enlarged salivary glands , a spacious stomach , and an elongated caecum (lower gut) that facilitates fermentation . The hairy-eared dwarf lemur ( Allocebus trichotis ) reportedly has
747-439: A four-tooth toothcomb due to the loss of either a pair of canines or incisors. Because the lower canine is either included in the toothcomb or lost, the lower dentition can be difficult to read, especially since the first premolar (P2) is often shaped like a canine (caniniform) to fill the canine's role. In folivorous (leaf-eating) lemurs, except for indriids, the upper incisors are greatly reduced or absent. Used together with
830-474: A functional strepsirrhine toothcomb. In the case of the aye-aye, the morphology of the deciduous incisors, which are lost shortly after birth, indicates that its ancestors had a toothcomb. These milk teeth are lost shortly after birth and are replaced by open-rooted, continually growing ( hypselodont ) incisors. The toothcomb in lemurs normally consists of six teeth (four incisors and two canines), although indriids, monkey lemurs, and some sloth lemurs only have
913-487: A highly mobile, filiform (filament-shaped) middle finger for extracting food from tiny holes; large, bat -like ears for detecting hollow spaces within trees; and use of self-generated acoustical cues to forage. Lemurs are unusual since they have great variability in their social structure, yet generally lack sexual dimorphism in size and canine tooth morphology. However, some species tend towards having larger females, and two species of true lemur (genus Eulemur ),
SECTION 10
#1732851813345996-520: 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 go 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,
1079-435: A more thorough analysis. Lemurs vary greatly in size. They include the smallest primates in the world and, until recently, also included some of the largest. They currently range in size from about 30 g (1.1 oz) for Madame Berthe's mouse lemur ( Microcebus berthae ) up to 7–9 kg (15–20 lb) for the indri ( Indri indri ) and diademed sifaka ( Propithecus diadema ). One recently extinct species rivaled
1162-401: 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
1245-415: A very long tongue , allowing it to feed on nectar . Likewise, the red-bellied lemur ( Eulemur rubriventer ) has a feathery brush-shaped tongue, also uniquely adapted to feed on nectar and pollen. The aye-aye has evolved some traits that are unique among primates, making it stand out among the lemurs. Such traits include continuously growing, rodent-like front teeth for gnawing through wood and hard seeds;
1328-435: A wide variety of fruits and leaves, while some are specialists. Two species of lemurs may coexist in the same forest due to different diets. Lemur research during the 18th and 19th centuries focused on taxonomy and specimen collection. Modern studies of lemur ecology and behavior did not begin in earnest until the 1950s and 1960s. Initially hindered by political issues on Madagascar during the mid-1970s, field studies resumed in
1411-703: Is a great mistake to ignore the threat: it will not just go away, it must be countered. ... Scientists, but most especially archaeologists, are in the front line; we, not the artists or the politicians, are the ones with ammunition to stem the tide of creationist rubbish, and relegate it to Monty Python's Flying Circus where it belongs." Groves' research interests included human evolution , primates , mammalian taxonomy , skeletal analysis , biological anthropology , ethnobiology , cryptozoology , and biogeography . He conducted extensive fieldwork in Kenya , Tanzania , Rwanda , India , Iran , China , Indonesia , Sri Lanka and
1494-655: Is basal to all Lemuriformes, and 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. Relationships among lemur families have also proven to be problematic and have yet to be definitively resolved. To further complicate the issue, several Paleogene fossil primates from outside Madagascar, such as Bugtilemur , have been classified as lemurs. However, scientific consensus does not accept these assignments based on genetic evidence, and therefore it
1577-595: Is generally accepted that the Malagasy primates are monophyletic. Another area of contention is the relationship between the sportive lemurs and the extinct koala lemurs (Megaladapidae). Formerly grouped in the same family due to similarities in dentition, they are no longer considered to be closely related due to genetic studies. More taxonomic changes have occurred at the genus level, although these revisions have proven more conclusive, often supported by genetic and molecular analysis. The most noticeable revisions included
1660-670: Is highest in the rainforests of the east coast. Despite their adaptations for weathering extreme adversity, habitat destruction and hunting have resulted in lemur populations declining sharply, and their diversity has diminished, with the recent extinction of at least 17 species in eight genera, known collectively as the subfossil lemurs . Most of the approximately 100 species and subspecies of lemur are either threatened or endangered. Unless trends change, extinctions are likely to continue. Until recently, giant lemurs existed on Madagascar. Now represented only by recent or subfossil remains, they were modern forms that were once part of
1743-597: Is known from subfossil finds. 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
SECTION 20
#17328518133451826-516: Is now used in the colloquial sense in reference to all Malagasy primates. Lemur taxonomy is controversial, and not all experts agree, particularly with the recent increase in the number of recognized species. According to Russell Mittermeier , the president of Conservation International (CI), taxonomist Colin Groves , and others, there are nearly 100 recognized species or subspecies of extant (or living) lemur, divided into five families and 15 genera. Because genetic data indicates that
1909-406: Is often viewed as a harbinger of evil and death 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
1992-506: Is smaller than that of anthropoid primates. As with all strepsirrhine primates, they have a "wet nose" ( rhinarium ). Lemurs are generally the most social of the strepsirrhine primates, living in groups known as troops. They communicate more with scents and vocalizations than with visual signals. Lemurs have a relatively low basal metabolic rate , and as a result may exhibit dormancy such as hibernation or torpor . They also have seasonal breeding and female social dominance . Most eat
2075-631: 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
2158-460: 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 dry 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
2241-504: The Eocene (56 to 34 mya ) or Paleocene (66 to 56 mya). Adapiforms, however, lack a specialized arrangement of teeth, known as a toothcomb , which nearly all living strepsirrhines possess. A more recent hypothesis is that lemurs descended from lorisoids (loris-like) primates. This is supported by comparative studies of the cytochrome b gene and the presence of the strepsirrhine toothcomb in both groups. Instead of being
2324-657: The International Union for Conservation of Nature (IUCN) considers lemurs to be the world's most endangered mammals, noting that as of 2013 up to 90% of all lemur species confront the threat of extinction in the wild within the next 20 to 25 years. Ring-tailed lemurs are an iconic flagship species . Collectively, lemurs exemplify the biodiverse fauna of Madagascar and have facilitated the emergence of eco-tourism . In addition, conservation organizations increasingly seek to implement community-based approaches to save lemur species and promote sustainability. Carl Linnaeus ,
2407-583: The Mozambique Channel , a deep channel between Africa and Madagascar with a minimum width of about 560 km (350 mi). In 1915, paleontologist William Diller Matthew noted that the mammalian biodiversity on Madagascar (including lemurs) can only be accounted for by random rafting events , where very small populations rafted from nearby Africa on tangled mats of vegetation, which get flushed out to sea from major rivers. This form of biological dispersal can occur randomly over millions of years. In
2490-560: The Smithsonian Institution Press in 2001, and Ungulate Taxonomy, co-authored by Peter Grubb (2011, Johns Hopkins Press). He was an active member of the Australian Skeptics and had many published sceptical papers, as well as research papers covering his other research interests. He also conducted regular debates with creationists and anti-evolutionists . Groves opposed the arguments of creationism , stating "It
2573-626: The University of California, Berkeley , Queen Elizabeth College and the University of Cambridge . Groves emigrated to Australia in 1973 and joined the Australian National University , where he was promoted to full professor in 2000 and remained emeritus professor until his death. Along with the Czech biologist Professor Vratislav Mazák , Groves was the describer of Homo ergaster . Groves also wrote Primate Taxonomy published by
Aye-aye - Misplaced Pages Continue
2656-471: The gorilla in size, at 160–200 kg (350–440 lb) for Archaeoindris fontoynonti . Like all primates, lemurs have five divergent digits with nails (in most cases) on their hands and feet. Most lemurs possess a laterally compressed, elongated nail, called a toilet-claw , on the second toe and use it for scratching and grooming. In addition to the toilet-claw, lemurs share a variety of other traits with other strepsirrhine primates, which include
2739-416: The gray-headed lemur ( E. albocollaris ) and the red lemur ( E. rufus ), exhibit size differences in canine teeth. True lemurs show sexual dichromatism (sexual differences in fur coloration), but the difference between the genders varies from strikingly obvious, as in the blue-eyed black lemur ( E. macaco ), to nearly imperceptible in the case of the common brown lemur ( E. fulvus ). Crypsis , or
2822-449: The toothcomb of most lemurs, the bottom incisors and canine teeth are procumbent (face forward rather than up) and finely spaced, thus providing a tool for either grooming or feeding. For instance, indri use their toothcomb not only for grooming, but also to pry out the large seeds from the tough epicarp of Beilschmiedia fruits, while fork-marked lemurs use their relatively long toothcomb to cut through tree bark to induce
2905-525: The 1940s, American paleontologist George Gaylord Simpson coined the term "sweepstakes hypothesis" for such random events. Rafting has since been the most accepted explanation for the lemur colonization of Madagascar, but until recently, this trip was thought to be very unlikely because strong ocean currents flow away from the island. In January 2010 , a report demonstrated that around 60 mya both Madagascar and Africa were 1,650 km (1,030 mi) south of their present-day positions, placing them in
2988-709: The 1980s. Lemurs are important for research because their mix of ancestral characteristics and traits shared with anthropoid primates can yield insights on primate and human evolution . Most species have been discovered or promoted to full species status since the 1990s; however, lemur taxonomic classification is controversial and depends on which species concept is used. Many lemur species remain endangered due to habitat loss and hunting. Although local traditions, such as fady , generally help protect lemurs and their forests, illegal logging , economic privation and political instability conspire to thwart conservation efforts. Because of these threats and their declining numbers,
3071-482: The 30-gram (1.1 oz) mouse lemur to the 9-kilogram (20 lb) indri . Since the arrival of humans on the island around 2,000 years ago, over a dozen species of " giant lemurs " larger than living lemur species have become extinct, including the gorilla-sized Archaeoindris . Lemurs share many common basal primate traits, such as divergent digits on their hands and feet, and nails instead of claws (in most species). However, their brain-to-body size ratio
3154-417: The adjacent image. Lemur taxonomy has changed significantly since the first taxonomic classification of lemurs by Carl Linnaeus in 1758. One of the greatest challenges has been the classification of the aye-aye, which has been a topic of debate up until very recently. Until Richard Owen published a definitive anatomical study in 1866, early naturalists were uncertain whether the aye-aye (genus Daubentonia )
3237-468: The arrival of humans roughly 1500 to 2000 years ago, lemurs were found all across the island. However, early settlers quickly converted the forests to rice paddies and grassland through slash-and-burn agriculture (known locally as tavy ), restricting lemurs to approximately 10% of the island's area, ~60,000 km (23,000 sq mi). Today, the diversity and complexity of lemur communities increases with floral diversity and precipitation and
3320-404: 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 60 centimetres (2 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
3403-449: 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 . A second species, Daubentonia robusta , appears to have become extinct at some point within the last 1000 years, and
Aye-aye - Misplaced Pages Continue
3486-479: The aye-aye is considered evil by local cultures, and is killed as such. The forests of Madagascar are declining in range due to deforestation . Local farmers will kill aye-ayes to protect their crops; aye-aye poaching is another major issue. 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
3569-402: 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 ly diverging of lemurs . The most parsimonious explanation for this
3652-526: The aye-aye, and the extinct sloth lemurs , monkey lemurs , and koala lemurs have reduced dentitions, having lost incisors, canines, or premolars. The ancestral deciduous dentition is 2.1.3 2.1.3 , but young indriids, aye-ayes, koala lemurs, sloth lemurs, and probably monkey lemurs have fewer deciduous teeth. There are also noticeable differences in dental morphology and tooth topography between lemurs. Indri , for instance, have teeth that are perfectly adapted for shearing leaves and crushing seeds. In
3735-413: The canopy among the vines and branches. The aye-aye was thought to be extinct in 1933, but was rediscovered in 1957. In 1966, nine individuals were transported to Nosy Mangabe , an island near Maroantsetra off eastern Madagascar. 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 four main reasons:
3818-455: The case of mouse lemurs, the gray mouse lemur ( M. murinus ), golden-brown mouse lemur ( M. ravelobensis ), and Goodman's mouse lemur ( M. lehilahytsara ) were considered the same species until recently, when genetic tests identified them as cryptic species. The lemur dentition is heterodont (having multiple tooth morphologies) and derives from an ancestral primate permanent dentition of 2.1.3.3 2.1.3.3 . Indriids, sportive lemurs,
3901-504: The direct ancestors of lemurs, the adapiforms may have given rise to both the lemurs and lorisoids, a split that would be supported by molecular phylogenetic studies. The later split between lemurs and lorises is thought to have occurred approximately 62 to 65 mya according to molecular studies, although other genetic tests and the fossil record in Africa suggest more conservative estimates of 50 to 55 mya for this divergence. However,
3984-564: The environment. Lemurs have adapted to fill many open ecological niches since making their way to Madagascar. Their diversity in both behavior and morphology (outward appearance) rivals that of the monkeys and apes found elsewhere in the world. Ranging in size from the 30 g (1.1 oz) Madame Berthe's mouse lemur , the world's smallest primate, to the recently extinct 160–200 kg (350–440 lb) Archaeoindris fontoynonti , lemurs evolved diverse forms of locomotion, varying levels of social complexity, and unique adaptations to
4067-510: 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
4150-434: 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
4233-607: 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. Lemur Lemurs ( / ˈ l iː m ər / LEE -mər ; from Latin lemures lit. ' ghosts ' or ' spirits ' ) are wet-nosed primates of the superfamily Lemuroidea ( / l ɛ m j ʊ ˈ r ɔɪ d i ə / lem-yuurr- OY -dee-ə ), divided into 8 families and consisting of 15 genera and around 100 existing species . They are endemic to
SECTION 50
#17328518133454316-416: The flow of tree sap . The toothcomb is kept clean by the sublingua or "under-tongue", a specialized structure that acts like a toothbrush to remove hair and other debris. The sublingua extends below the tip of the tongue and is tipped with keratinized , serrated points that rake between the front teeth. Only the aye-aye, the extinct giant aye-aye , and the largest of the extinct giant sloth lemurs lack
4399-466: The founder of modern binomial nomenclature , gave lemurs their name as early as 1758. With his declaration of the genus Lemur in the 10th edition of Systema Naturae , he included three species: Lemur tardigradus (the red slender loris , now known as Loris tardigradus ), Lemur catta (the ring-tailed lemur ), and Lemur volans (the Philippine colugo , now known as Cynocephalus volans ). Although
4482-421: The full range of lemur sizes. Daubentoniidae Lemuridae Indriidae Lepilemuridae Cheirogaleidae Daubentoniidae Lepilemuridae Cheirogaleidae Lemuridae † Megaladapidae Indriidae † Palaeopropithecidae † Archaeolemuridae From a taxonomic standpoint, the term "lemur" originally referred to the genus Lemur , which currently contains only the ring-tailed lemur . The term
4565-550: The gradual split of a broadly defined genus Lemur into separate genera for the ring-tailed lemur , ruffed lemurs , and brown lemurs due to a host of morphological differences. Due to several taxonomic revisions by Russell Mittermeier, Colin Groves, and others, the number of recognized lemur species has grown from 33 species and subspecies in 1994 to approximately 100 in 2008. With continuing cytogenetic and molecular genetic research, as well as ongoing field studies , particularly with cryptic species such as mouse lemurs,
4648-455: 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. 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
4731-425: The inability of humans to visually distinguish between two or more distinct species, has recently been discovered among lemurs, particularly within the sportive lemurs ( Lepilemur ) and mouse lemurs ( Microcebus ). With sportive lemurs, subspecies were traditionally defined based on slight morphological differences, but new genetic evidence has supported giving full species status to these regional populations. In
4814-456: The island of Madagascar . Most existing lemurs are small, have a pointed snout, large eyes, and a long tail. They chiefly live in trees and are active at night . Lemurs share resemblance with other primates , but evolved independently from monkeys and apes . Due to Madagascar's highly seasonal climate, lemur evolution has produced a level of species diversity rivaling that of any other primate group. Living lemurs range in weight from
4897-460: The lemurs and the rest of the terrestrial Malagasy fauna from mainland Africa. Isolated on Madagascar with only a limited number of mammalian competitors, the lemurs did not have to compete with other evolving arboreal mammalian groups, such as squirrels . They were also spared from having to compete with monkeys , which evolved later. The intelligence, aggression, and deceptiveness of monkeys gave them an advantage over other primates in exploiting
4980-769: The local climate. Lemurs lack any shared traits that make them stand out from all other primates. Different types of lemurs have evolved unique combinations of unusual traits to cope with Madagascar's harsh, seasonal climate. These traits can include seasonal fat storage, hypometabolism (including torpor and hibernation ), small group sizes, low encephalization (relative brain size), cathemerality (activity both day and night), and strict breeding seasons . Extreme resource limitations and seasonal breeding are also thought to have given rise to three other relatively common lemur traits: female social dominance , sexual monomorphism, and male–male competition for mates involving low levels of agonism , such as sperm competition . Before
5063-495: The mammalian order Rodentia and 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 basally diverging branch of the strepsirrhine suborder, and of indeterminate relation to all living primates. In 1931, Anthony and Coupin classified
SECTION 60
#17328518133455146-408: 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
5229-490: The name resembles the Malagasy name "hai hai" or "hay hay", (also ahay , aiay , haihay ) 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
5312-431: 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 4 km ( 2 + 1 ⁄ 2 mi) a night. Though foraging is usually solitary, they occasionally forage in groups. Individual movements within
5395-445: The number of recognized lemur species is likely to keep growing. However, the rapid increase in the number of recognized species has had its critics among taxonomists and lemur researchers. Since classifications ultimately depend on the species concept used, conservationists often favor definitions that result in the splitting of genetically distinct populations into separate species to gain added environmental protection. Others favor
5478-484: The oldest lemur fossils on Madagascar are actually subfossils dating to the Late Pleistocene . Once part of the supercontinent Gondwana , the island of Madagascar has been isolated since it broke away from eastern Africa (~160 mya), Antarctica (~80–130 mya), and India (~80–90 mya). Since ancestral lemurs are thought to have originated in Africa around 62 to 65 mya, they must have crossed
5561-545: The period of parenting, a female becomes the dominant figure over males, likely to secure better access to food while caring for her young. The infant remains in a nest for up to two months before venturing out, but it takes another seven months before the young aye-aye can maneuver the canopy as skillfully as an adult. The aye-aye is an omnivore and commonly eats seeds, nuts, fruits, nectar, plant exudates and fungi, but also xylophagous, or wood boring, insect larvae (especially cerambycid beetle larvae) and honey. Aye-ayes tap on
5644-471: 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 male's genitalia are similar to those of canids , with a large prostate and long baculum . The aye-aye is a nocturnal and arboreal animal meaning that it spends most of its life high in
5727-417: The recently extinct subfossil lemurs were closely related to living lemurs, an additional three families, eight genera, and 17 species can be included in the total. In contrast, other experts have labeled this as taxonomic inflation , instead preferring a total closer to 50 species. The classification of lemurs within the suborder Strepsirrhini is equally controversial, although most experts agree on
5810-399: 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 extracting grubs and insects out of trees, using the hooked nail. The finger is unique in the animal kingdom in that it possesses a ball-and-socket metacarpophalangeal joint , can reach the throat through
5893-656: The rest of the lemurs were placed in Lemuriformes and the lorisoids in Lorisiformes. Although it is generally agreed that the aye-aye is the most basal member of the lemur clade, the relationship between the other four families is less clear since they diverged during a narrow 10 to 12 million-year window between the Late Eocene (42 mya) and into the Oligocene (30 mya). The two main competing hypotheses are shown in
5976-640: The rich lemur diversity that has evolved in isolation. Some of their adaptations were unlike those seen in their living relatives. All 17 extinct lemurs were larger than the extant (living) forms, some weighing as much as 200 kg (440 lb), and are thought to have been active during the day. Not only were they unlike the living lemurs in both size and appearance, they also filled ecological niches that either no longer exist or are now left unoccupied. Large parts of Madagascar, which are now devoid of forests and lemurs, once hosted diverse primate communities that included more than 20 lemur species covering
6059-451: The same phylogenetic tree . In one taxonomy, the infraorder Lemuriformes contains all living strepsirrhines in two superfamilies, Lemuroidea for all lemurs and Lorisoidea for the lorisoids ( lorisids and galagos). Alternatively, the lorisoids are sometimes placed in their own infraorder, Lorisiformes, separate from the lemurs. In another taxonomy published by Colin Groves, the aye-aye was placed in its own infraorder, Chiromyiformes, while
6142-649: 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
6225-599: The term lemur was first intended for slender lorises , it was soon limited to the endemic Malagasy primates, which have been known as collectively "lemurs" ever since. The name lemur is derived from the Latin term lemures , which refers to specters or ghosts that were exorcised during the Lemuria festival of ancient Rome. Linnaeus was familiar with the works of Virgil and Ovid , both of whom mentioned lemures. Seeing an analogy that fit with his naming scheme, he adapted
6308-906: The term lemur was selected because of the nocturnal activity and slow movements of the red slender loris: Lemures dixi hos, quod noctu imprimis obambulant, hominibus quodanmodo similes, & lento passu vagantur. I call them lemurs, because they go around mainly by night, in a certain way similar to humans, and roam with a slow pace. Lemurs are primates belonging to the suborder Strepsirrhini . Like other strepsirrhine primates , such as lorises , pottos , and galagos , they share ancestral (or plesiomorphic ) traits with early primates. In this regard, lemurs are popularly confused with ancestral primates; however, lemurs did not give rise to monkeys and apes ( simians ). Instead, they evolved independently in isolation on Madagascar . All modern strepsirrhines including lemurs are traditionally thought to have evolved from early primates known as adapiforms during
6391-515: The term "lemur" for these nocturnal primates. It was noted in 2012 that many sources had commonly and falsely assumed that Linnaeus was referring to the ghost-like appearance, reflective eyes , and ghostly cries of Madagascar's lemurs when he selected the name. Up until then, it had also been speculated that Linnaeus may also have known that some Malagasy people believed that lemurs were the souls of their ancestors . However, both claims were discredited since according to Linnaeus' own explanation,
6474-703: The toothcomb on the mandible (lower jaw), this complex is reminiscent of an ungulate browsing pad . Lemurs are unusual among primates for their rapid dental development, particularly among the largest species. For example, indriids have relatively slow body growth but extremely fast tooth formation and eruption . By contrast, anthropoid primates exhibit slower dental development with increased size and slower morphological development. Lemurs are also dentally precocious at birth, and have their full permanent dentition at weaning . Colin Groves Colin Peter Groves (24 June 1942 – 30 November 2017)
6557-561: 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
6640-503: 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
6723-452: The wood using its forward-slanting incisors to create a small hole into 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 living mammal species known to find food in this way are the striped possum and trioks (genus Dactylopsila ) of northern Australia and New Guinea, which are marsupials. From an ecological point of view,
6806-416: Was a primate , rodent , or marsupial . However, the placement of the aye-aye within the order Primates remained problematic until very recently. Based on its anatomy, researchers have found support for classifying the genus Daubentonia as a specialized indriid , a sister group to all strepsirrhines, and as an indeterminate taxon within the order Primates. Molecular tests have now shown Daubentoniidae
6889-600: Was a British-Australian biologist and anthropologist. Groves was Professor of Biological Anthropology at the Australian National University in Canberra , Australia. Born in England, Groves completed a Bachelor of Science at University College London in 1963, and a Doctor of Philosophy at the Royal Free Hospital School of Medicine in 1966. From 1966 to 1973, he was a postdoctoral researcher and teaching fellow at
#344655