114-630: See text Night monkeys , also known as owl monkeys or douroucoulis ( / d uː r uː ˈ k uː l i z / ), are nocturnal New World monkeys of the genus Aotus , the only member of the family Aotidae ( / eɪ ˈ ɒ t ɪ d iː / ). The genus comprises eleven species which are found across Panama and much of South America in primary and secondary forests, tropical rainforests and cloud forests up to 2,400 metres (7,900 ft). Night monkeys have large eyes which improve their vision at night, while their ears are mostly hidden, giving them their name Aotus , meaning "earless". Night monkeys are
228-427: A dental formula of 2.1.3.3 2.1.3.3 or 2.1.3.2 2.1.3.2 (consisting of 2 incisors, 1 canine, 3 premolars, and 2 or 3 molars). This is in contrast with Old World Anthropoids, including gorillas , chimpanzees , bonobos , siamangs , gibbons , orangutans , and most humans , which share a dental formula of 2.1.2.3 2.1.2.3 . Many New World monkeys are small and almost all are arboreal , so knowledge of them
342-435: A grooming claw on the second toe of each foot for scratching in areas that are inaccessible to the mouth and tongue. Adapiforms may have had a grooming claw, but there is little evidence of this. The toothcomb consists of either two or four procumbent lower incisors and procumbent lower canine teeth followed by a canine-shaped premolar . It is used to comb the fur during oral grooming. Shed hairs that accumulate between
456-467: A tapetum lucidum , the reflective layer behind the retina possessed by many nocturnal animals. Other sources say they have a tapetum lucidum composed of collagen fibrils. At any rate, night monkeys lack the tapetum lucidum composed of riboflavin crystals possessed by lemurs and other strepsirrhines , which is an indication that their nocturnality is a secondary adaption evolved from ancestrally diurnal primates. Their ears are rather difficult to see; this
570-613: A toothcomb , a specialized set of teeth in the front, lower part of the mouth mostly used for combing fur during grooming . Many of today's living strepsirrhines are endangered due to habitat destruction , hunting for bushmeat , and live capture for the exotic pet trade. Both living and extinct strepsirrhines are behaviorally diverse, although all are primarily arboreal (tree-dwelling). Most living lemuriforms are nocturnal , while most adapiforms were diurnal . Both living and extinct groups primarily fed on fruit , leaves , and insects . The taxonomic name Strepsirrhini derives from
684-619: A cercamoniine, but also may have been a stem lemuriform. Azibiids from Algeria date to roughly the same time and may be a sister group of the djebelemurids . Together with Plesiopithecus from the late Eocene Egypt, the three may qualify as the stem lemuriforms from Africa. Molecular clock estimates indicate that lemurs and the lorisoids diverged in Africa during the Paleocene, approximately 62 mya. Between 47 and 54 mya, lemurs dispersed to Madagascar by rafting . In isolation,
798-468: A frequency range of 190–1,950 Hz. Unusual among the New World monkeys, they are monochromats , that is, they have no colour vision, presumably because it is of no advantage given their nocturnal habits. They have a better spatial resolution at low light levels than other primates, which contributes to their ability to capture insects and move at night. Night monkeys live in family groups consisting of
912-609: A great degree of energy expenditure, but in the case of night monkey males, food sharing confers offspring survival advantages. As lactating females may be too weak to forage themselves, they may lose the ability to nurse their child, food sharing therefore ensures that offspring will be well feed. The act of food sharing is only observed among species where there is a high degree of fidelity in paternity. Giving up valuable food sources would not confer an evolutionary advance unless it increased an individual's fitness; in this case, paternal care ensures success of offspring and therefore increases
1026-521: A high mist and moisture content which allows for lush and rich vegetation to grow year round, providing excellent food and lodging sources. The Peruvian night monkey , like Nancy Ma's night monkey, is endemic to the Peruvian Andes however it is found at a higher elevation, approximately 800–2,400 metres (2,600–7,900 ft) above sea level and therefore exploits different niches of this habitat. The distribution of A. azare , extends further towards
1140-400: A mated pair and their immature offspring. Family groups defend territories by vocal calls and scent marking . The night monkey is socially monogamous, and all night monkeys form pair bonds . Only one infant is born each year. The male is the primary caregiver, and the mother carries the infant for only the first week or so of its life. This is believed to have developed because it increases
1254-502: A more specialized and younger branch of adapiform primarily from Europe. Scandentia (treeshrews) Dermoptera (colugos) † Plesiadapiformes Simians Tarsiers † Omomyiformes † Adapiformes Lorisoids Lemurs Lemurs rafted from Africa to Madagascar between 47 and 54 mya, whereas the lorises split from the African galagos around 40 mya and later colonized Asia. The lemuriforms, and particularly
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#17327756956181368-459: A new suborder, Simiolemuriformes, to suggest that strepsirrhines are more closely related to simians than tarsiers. However, no clear relationship between the two had been demonstrated by the early 2000s. The idea reemerged briefly in 2009 during the media attention surrounding Darwinius masillae (dubbed "Ida"), a cercamoniine from Germany that was touted as a " missing link between humans and earlier primates" (simians and adapiforms). However,
1482-646: A predator approach too quickly. Activity at night also permits night monkeys to avoid aggressive interactions with other species such as competing for food and territorial disputes; as they are active when most other species are inactive and resting. Night monkeys also benefit from a nocturnal life style as activity in the night provides a degree of protection from the heat of the day and the thermoregulation difficulties associated. Although night monkey, like all primates are endothermic, meaning they are able to produce their own heat, night monkeys undergo behavioural thermoregulation in order to minimize energy expenditure. During
1596-569: A single gene on the X-chromosome to produce pigments that absorb medium and long wavelength light, which contrasts with short wavelength light. As a result, males rely on a single medium/long pigment gene and are dichromatic , as are homozygous females. Heterozygous females may possess two alleles with different sensitivities within this range, and so can display trichromatic vision. Platyrrhines also differ from Old World monkeys in that they have twelve premolars instead of eight; having
1710-662: A sister group to the living strepsirrhines. They are included in Strepsirrhini, and are considered basal members of the clade. Although their status as true primates is not questioned, the questionable relationship between adapiforms and other living and fossil primates leads to multiple classifications within Strepsirrhini. Often, adapiforms are placed in their own infraorder due to anatomical differences with lemuriforms and their unclear relationship. When shared traits with lemuriforms (which may or may not be synapomorphic) are emphasized, they are sometimes reduced to families within
1824-533: A smaller brain than comparably sized simians , large olfactory lobes for smell, a vomeronasal organ to detect pheromones , and a bicornuate uterus with an epitheliochorial placenta . Their eyes contain a reflective layer to improve their night vision , and their eye sockets include a ring of bone around the eye, but they lack a wall of thin bone behind it. Strepsirrhine primates produce their own vitamin C , whereas haplorhine primates must obtain it from their diets. Lemuriform primates are characterized by
1938-429: A specialized dental structure called a "toothcomb", with the exception of the aye-aye, in which the structure has been modified into two continually growing (hypselodont) incisors (or canine teeth ), similar to those of rodents . Often, the toothcomb is incorrectly used to characterize all strepsirrhines. Instead, it is unique to lemuriforms and is not seen among adapiforms. Lemuriforms groom orally, and also possess
2052-420: A substantial portion of the night monkey's activities occurring during the dark hours of the night, there is a much lower reliance of visual and tactile cues. When foraging at night, members of the family Aotidae will smell fruits and leaves before ingesting to determine the quality and safety of the food source. As they are highly frugivorous and cannot perceive colour well, smell becomes the primary determinant of
2166-471: A third transatlantic dispersal event comes from a fossil molar belonging to Ashaninkacebus simpsoni , which has strong affinities with stem anthropoid primates of South Asian origin, the Eosimiidae . The chromosomal content of the ancestor species appears to have been 2n = 54. In extant species, the 2n value varies from 16 in the titi monkey to 62 in the woolly monkey . A Bayesian estimate of
2280-549: 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
2394-409: Is a synapomorphy (shared, derived trait) seen among lemuriforms, although it is frequently and incorrectly used to define the strepsirrhine clade. Strepsirrhine primates are also united in possessing an epitheliochorial placenta . Unlike the tarsiers and simians, strepsirrhines are capable of producing their own vitamin C and do not need it supplied in their diet. Further genetic evidence for
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#17327756956182508-800: Is a preference for scents of a particular type; those which indicate reproductive receptivity, which increases species fitness by facilitating the production of offspring. According to the IUCN (the International Union for Conservation of Nature ), the Peruvian night monkey is classified an Endangered species , four species are Vulnerable , four are Least-concern species , and two are data deficient. Most night monkey species are threatened by varying levels of habitat loss throughout their range, caused by agricultural expansion , cattle ranching, logging, armed conflict, and mining operations. To date, it
2622-463: Is an invaluable tool in determining conservation strategies for these species and raising awareness for consequences of the anthropogenic threats facing these primates. Radio-collaring of free ranging primates proposes a method of obtaining more accurate and complete data surrounding primate behavior patterns. This in turn can aid in understanding what measures need to be taken to promote the conservation of these species. Radio collaring not only allows for
2736-476: Is approximately 117– 159 days but varies from species to species. Birthing season extends from September to March and is species-dependent, with one offspring being produced per year; however, in studies conducted in captivity, twins were observed. Night monkeys reach puberty at a relatively young age, between 7 and 11 months, and most species attain full sexual maturity by the time they reach 2 years of age. A. azare represents an exception reaching sexual maturity by
2850-460: Is bonded to and prevent other conspecifics from attempting to mate with her. Mate guarding likely evolved as a means of reducing energy expenditure when mating. As night monkey territories generally have some edge overlap, there can be a large number of individuals coexisting in one area which may make it difficult for a male to defend many females at once due to high levels of interspecific competition for mates. Night monkeys form bonded pairs and
2964-403: Is estimated that more than 62% of the habitat of the Peruvian night monkey has been destroyed or degraded by human activities. However, some night monkey species have become capable of adapting exceptionally well to anthropogenic influences in their environment. Populations of Peruvian night monkey have been observed thriving in small forest fragments and plantation or farmland areas, however this
3078-613: Is highly likely that the ancestors of the family Aotidae did not exhibit nocturnality and were rather diurnal species. The presence of nocturnal behavior in Aotidae therefore exemplifies a derived trait; an evolutionary adaptation that conferred greater fitness advantages onto the night monkey. Night monkey share some similarities with nocturnal prosimians including low basal metabolic rate, small body size and good ability to detect visual cues at low light levels. Their responses to olfactory stimulus are intermediate between those of
3192-627: Is less comprehensive than that of the more easily observed Old World monkeys. Unlike most Old World monkeys, many New World monkeys form monogamous pair bonds , and show substantial paternal care of young. They eat fruits, nuts, insects, flowers, bird eggs, spiders, and small mammals. Unlike humans and most Old World monkeys, their thumbs are not opposable (except for some cebids ). Strepsirrhines † Adapiformes Lemuriformes (See text) sister: Haplorhini Strepsirrhini or Strepsirhini ( / ˌ s t r ɛ p s ə ˈ r aɪ n i / ; STREP -sə- RY -nee )
3306-399: Is likely possible given their small body size and may not be an appropriate alternate habitat option for other larger night monkey species. Studies have already been conducted into the feasibility of agroforestry; plantations which simultaneously support local species biodiversity. In the case of A. miconax , coffee plantations with introduced shade trees, provided quality habitat spaces. While
3420-634: Is slightly taller than the female, measuring 346 and 341 millimetres (13.6 and 13.4 in), respectively. Night monkeys can be found in Panama , Colombia , Ecuador , Peru , Brazil , Paraguay , Argentina , Bolivia , and Venezuela . The species that live at higher elevations tend to have thicker fur than the monkeys at sea level. Night monkeys can live in forests undisturbed by humans ( primary forest ) as well as in forests that are recovering from human logging efforts ( secondary forest ). A primary distinction between red-necked and gray-necked night monkeys
3534-677: Is spatial distribution. Gray-necked night monkeys ( Aotus lemurinus group) are found north of the Amazon River, while the red-necked group ( Aotus azare group) are localized south of the Amazon River. Red-necked night monkeys are found throughout various regions of the Amazon rainforest of South America, with some variation occurring between the four species. Nancy Ma's night monkey occurs in both flooded and unflooded tropical rainforest regions of Peru, preferring moist swamp and mountainous areas. This species has been observed nesting in regions of
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3648-474: Is still used to illustrate the behavioral ecology of tarsiers relative to the other primates. In addition to the controversy over tarsiers, the debate over the origins of simians once called the strepsirrhine clade into question. Arguments for an evolutionary link between adapiforms and simians made by paleontologists Gingerich, Elwyn L. Simons , Tab Rasmussen , and others could have potentially excluded adapiforms from Strepsirrhini. In 1975, Gingerich proposed
3762-539: Is the feature used most commonly to distinguish between the two groups. The clade for New World monkeys, Platyrrhini, means "flat nosed". The noses of New World monkeys are flatter than the narrow noses of Old World monkeys, and have side-facing nostrils. New World monkeys are the only monkeys with prehensile tails —in comparison with the shorter, non-grasping tails of the anthropoids of the Old World. Prehensility has evolved at least two distinct times in platyrrhines, in
3876-431: Is why their genus name, Aotus (meaning "earless") was chosen. There is little data on the weights of wild night monkeys. From the figures that have been collected, it appears that males and females are similar in weight; the heaviest species is Azara's night monkey at around 1,254 grams (2.765 lb), and the lightest is Brumback's night monkey , which weighs between 455 and 875 grams (1.003 and 1.929 lb). The male
3990-558: The Plasmodium falciparum parasite responsible for malaria. This trait caused them to be recommended by the World Health Organization as test subjects in the development of malaria vaccines. Up to 2008, more than 76 night monkeys died as a result of vaccine testing; some died from malaria, while others perished due to medical complications from the testing. Increased research and knowledge of night monkey ecology
4104-720: The Greek στρέψις strepsis "a turning round" and ῥίς rhis "nose, snout, (in pl.) nostrils" ( GEN ῥινός rhinos ), which refers to the appearance of the sinuous (comma-shaped) nostrils on the rhinarium or wet nose. The name was first used by French naturalist Étienne Geoffroy Saint-Hilaire in 1812 as a subordinal rank comparable to Platyrrhini ( New World monkeys ) and Catarrhini ( Old World monkeys ). In his description , he mentioned " Les narines terminales et sinueuses " ("Nostrils terminal and winding"). When British zoologist Reginald Innes Pocock revived Strepsirrhini and defined Haplorhini in 1918, he omitted
4218-708: The Isthmus of Panama had not yet formed, so ocean currents , unlike today, favoured westward dispersal, the climate was quite different, and the width of the Atlantic Ocean was less than the present 2,800 km (1,700 mi) width by about a third (possibly 1,000 km (600 mi) less, based on the current estimate of the Atlantic mid-ocean ridge formation processes spreading rate of 25 millimetres per year (1 in/year)). The non-platyrrhini Ucayalipithecus of Amazonian Peru who might have rafted across
4332-472: 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. Strepsirrhines are defined by their "wet" (moist) rhinarium (the tip of the snout) – hence the colloquial but inaccurate term "wet-nosed" – similar to the rhinaria of canines and felines. They also have
4446-407: The pygmy marmoset (the world's smallest monkey), at 14 to 16 cm (5.5 to 6.5 in) and a weight of 120 to 190 g (4.2 to 6.7 oz), to the southern muriqui , at 55 to 70 cm (22 to 28 in) and a weight of 12 to 15 kg (26 to 33 lb). New World monkeys differ slightly from Old World monkeys in several aspects. The most prominent phenotypic distinction is the nose, which
4560-505: The toothcomb of extant lemuriforms; however, this view is not strongly supported due to a lack of clear transitional fossils. Instead, lemuriforms may be descended from a very early branch of Asian cercamoniines or sivaladapids that migrated to northern Africa. Until discoveries of three 40 million-year-old fossil lorisoids ( Karanisia , Saharagalago , and Wadilemur ) in the El Fayum deposits of Egypt between 1997 and 2005,
4674-413: The African continent. Platyrrhini are currently conjectured to have dispersed to South America on a raft of vegetation across the Atlantic Ocean during the Eocene epoch, possibly via several intermediate now submerged islands. Several other groups of animals made the same journey across the Atlantic, notably including caviomorph rodents. At the time the New World monkeys dispersed to South America,
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4788-575: The Andes and has recently been introduced to Colombia, likely as a result of post-research release into the community. The black-headed night monkey is also found mainly in the Peruvian Amazon (central and upper Amazon), however its range extends throughout Brazil and Bolivia to the base of the Andes mountain chain. Night monkeys such like the black-headed night monkey, generally inhabit cloud forests; areas with consistent presence of low clouds with
4902-471: The Atelidae family (spider monkeys, woolly spider monkeys, howler monkeys, and woolly monkeys), and in capuchin monkeys ( Cebus ). Although prehensility is present in all of these primate species, skeletal and muscular-based morphological differences between these two groups indicate that the trait evolved separately through convergent evolution. The fully prehensile tails that have evolved in Atelidae allow
5016-765: The Atlantic Ocean, spanning Argentina, Bolivia and the drier, south western regions of Paraguay, however unlike the other red-necked night monkey species, it is not endemic to Brazil. During the daylight hours, night monkeys rest in shaded tree areas. These species have been observed exploiting four different types of tree nests, monkeys will rest in; holes formed in the trunks of trees, in concave sections of branches surrounded by creepers and epiphytes, in dense areas of epiphyte, climber and vine growth and in areas of dense foliage. These sleeping sites provide protection from environmental stressors such as heavy rain, sunlight and heat. Sleeping sites are therefore carefully chosen based upon tree age, density of trees, availability of space for
5130-461: The Atlantic between ~35–32 million years ago, are nested within the extinct Parapithecoidea from the Eocene of Afro-Arabia, suggesting that there were at least two separate dispersal events of primates to South America, Parvimico and Perupithecus from Peru appear to be at the base of the Platyrrhini, as are Szalatavus , Lagonimico , and Canaanimico . Possible evidence for
5244-465: The Early to Middle Eocene, evidence from genetics and recent fossil finds both suggest they may have been present during the early adaptive radiation . The origin of the earliest primates that the simians and tarsiers both evolved from is a mystery. Both their place of origin and the group from which they emerged are uncertain. Although the fossil record demonstrating their initial radiation across
5358-472: The Northern Hemisphere is very detailed, the fossil record from the tropics (where primates most likely first developed) is very sparse, particularly around the time that primates and other major clades of eutherian mammals first appeared. Lacking detailed tropical fossils, geneticists and primatologists have used genetic analyses to determine the relatedness between primate lineages and
5472-488: The Prosimii-Anthropoidea taxonomy is familiar and frequently seen in the research literature and textbooks. Strepsirrhines are traditionally characterized by several symplesiomorphic (ancestral) traits not shared with the simians, particularly the rhinarium. Other symplesiomorphies include long snouts , convoluted maxilloturbinals , relatively large olfactory bulbs , and smaller brains. The toothcomb
5586-412: The academic literature provides a basic framework for primate taxonomy, usually including several potential taxonomic schemes. Although most experts agree upon phylogeny , many disagree about nearly every level of primate classification. The most commonly recurring debate in primatology during the 1970s, 1980s, and early 2000s concerned the phylogenetic position of tarsiers compared to both simians and
5700-458: The age of 4. The name "night monkey" comes from the fact that all species are active at night and are, in fact, the only truly nocturnal monkeys (an exception is the subspecies of Azara's night monkey , Aotus azarae azarae , which is cathemeral ). Night monkeys make a notably wide variety of vocal sounds, with up to eight categories of distinct calls (gruff grunts, resonant grunts, sneeze grunts, screams, low trills, moans, gulps, and hoots), and
5814-470: The amount of time since they diverged . Using this molecular clock , divergence dates for the major primate lineages have suggested that primates evolved more than 80–90 mya, nearly 40 million years before the first examples appear in the fossil record. The early primates include both nocturnal and diurnal small-bodied species, and all were arboreal, with hands and feet specially adapted for maneuvering on small branches. Plesiadapiforms from
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#17327756956185928-545: The aye-aye (Daubentoniidae) in its own infraorder, Chiromyiformes. In some cases, plesiadapiforms are included within the order Primates, in which case Euprimates is sometimes treated as a suborder, with Strepsirrhini becoming an infraorder, and the Lemuriformes and others become parvorders. Regardless of the infraordinal taxonomy, Strepsirrhini is composed of three ranked superfamilies and 14 families, seven of which are extinct. Three of these extinct families included
6042-462: The case of lemurs, natural selection has driven this isolated population of primates to diversify significantly and fill a rich variety of ecological niches , despite their smaller and less complex brains compared to simians. The divergence between strepsirrhines, simians, and tarsiers likely followed almost immediately after primates first evolved. Although few fossils of living primate groups – lemuriforms, tarsiers, and simians – are known from
6156-548: The cladistic analysis was flawed and the phylogenetic inferences and terminology were vague. Although the authors noted that Darwinius was not a "fossil lemur", they did emphasize the absence of a toothcomb, which adapiforms did not possess. † Adapiformes stem lemuriforms Daubentoniidae other lemurs lorises galagos Within Strepsirrhini, two common classifications include either two infraorders (Adapiformes and Lemuriformes) or three infraorders (Adapiformes, Lemuriformes, Lorisiformes). A less common taxonomy places
6270-525: The climate cooled: The last of the adapiforms died out at the end of the Miocene (~7 mya). Adapiform primates are extinct strepsirrhines that shared many anatomical similarities with lemurs. They are sometimes referred to as lemur-like primates, although the diversity of both lemurs and adapiforms do not support this analogy. Like the living strepsirrhines, adapiforms were extremely diverse, with at least 30 genera and 80 species known from
6384-413: The coffee plantation benefited from the increased shade—reducing weed growth and desiccation, night monkeys used the space as a habitat, a connection corridor or stepping stone area between habitats that provided a rich food source. However, some researchers question the agroforestry concept, maintaining that monkeys are more susceptible to hunting, predator and pathogens in plantation fields, thus indicating
6498-433: The day allows for decreased interaction with diurnal predators. Members of the family Aotidae, apply the predation avoidance theory, choosing very strategic covered nests sites in trees. These primates carefully choose areas with sufficient foliage and vines to provide cover from the sun and camouflage from predators, but which simultaneously allow for visibility of ground predators and permit effective routes of escape should
6612-441: The day time usually involves the usage of energy in the form of calories and lipid reserves to cool the body down. Foraging during the night when it is cooler, and when there is less competition, supports the optimal foraging theory; maximize energy input while minimizing energy output. While protection from predators, interspecific interactions, and the harsh environment propose ultimate causes for nocturnal behavior as they increase
6726-562: The early Paleocene are sometimes considered "archaic primates", because their teeth resembled those of early primates and because they possessed adaptations to living in trees, such as a divergent big toe ( hallux ). Although plesiadapiforms were closely related to primates, they may represent a paraphyletic group from which primates may or may not have directly evolved, and some genera may have been more closely related to colugos , which are thought to be more closely related to primates. The first true primates (euprimates) do not appear in
6840-401: The early Eocene, although their most basal members share enough dental similarities to suggest that they diverged during the Paleocene (66–55 mya). Lemuriform origins are unclear and debated. American paleontologist Philip Gingerich proposed that lemuriform primates evolved from one of several genera of European adapids based on similarities between the front lower teeth of adapids and
6954-707: The energy expenditure of protecting a mate is reduced. Pair bonding may also be exhibited as a result of food distribution. In the forest, pockets of food can be dense or very patchy and scarce. Females, as they need energy stores to support reproduction are generally distributed to areas with sufficient food sources. Males will therefore also have to distribute themselves to be within proximity to females, this form of food distribution lends itself to social monogamy as finding females may become difficult if males have to constantly search for females which may be widely distributed depending on food availability that year. However, while this does explain social monogamy, it does not explain
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#17327756956187068-635: The extinct adapiforms and the lemuriform primates, which include lemurs and lorisoids ( lorises , pottos , and galagos ). Strepsirrhines diverged from the haplorhine primates near the beginning of the primate radiation between 55 and 90 mya. Older divergence dates are based on genetic analysis estimates, while younger dates are based on the scarce fossil record . Lemuriform primates may have evolved from either cercamoniines or sivaladapids , both of which were adapiforms that may have originated in Asia. They were once thought to have evolved from adapids ,
7182-420: The family Adapidae, which was divided into two or three subfamilies: Adapinae, Notharctinae, and sometimes Sivaladapinae. All North American adapiforms were lumped under Notharctinae, while the Old World forms were usually assigned to Adapinae. Around the 1990s, two distinct groups of European "adapids" began to emerge, based on differences in the postcranial skeleton and the teeth. One of these two European forms
7296-543: The family Prosimia (Prosimii) in 1811. The use of the tarsier-galago classification continued for many years until 1898, when Dutch zoologist Ambrosius Hubrecht demonstrated two different types of placentation (formation of a placenta ) in the two groups. English comparative anatomist William Henry Flower created the suborder Lemuroidea in 1883 to distinguish these primates from the simians, which were grouped under English biologist St. George Jackson Mivart 's suborder Anthropoidea (=Simiiformes). According to Flower,
7410-511: The father's fitness. Recent studies have proposed that night monkeys rely on olfaction and olfactory cues for foraging and communication significantly more than other diurnal primate species. This trend is reflected in the species physiology; members of Aotidae possess larger scent perception organs than their diurnal counterparts. The olfactory bulb, accessory olfactory bulb and volume of lateral olfactory tract are all larger in Aotus than in any of
7524-439: The female is not available for mating. Night monkeys also send chemical signals through urine to communicate reproductive receptivity. In many cases, male night monkeys have been observed drinking the urine of their female mate; it is proposed that the pheromones in the urine can indicate the reproductive state of a female and indicate ovulation. This is especially important in night monkeys as they cannot rely on visual cues, such as
7638-482: The fossil record as of the early 2000s. They diversified across Laurasia during the Eocene, some reaching North America via a land bridge . They were among the most common mammals found in the fossil beds from that time. A few rare species have also been found in northern Africa. The most basal of the adapiforms include the genera Cantius from North America and Europe and Donrussellia from Europe. The latter bears
7752-639: The fossil record until the early Eocene (~55 mya), at which point they radiated across the Northern Hemisphere during a brief period of rapid global warming known as the Paleocene–Eocene Thermal Maximum . These first primates included Cantius , Donrussellia , Altanius , and Teilhardina on the northern continents, as well as the more questionable (and fragmentary) fossil Altiatlasius from Paleocene Africa. These earliest fossil primates are often divided into two groups, adapiforms and omomyiforms . Both appeared suddenly in
7866-402: The fossil record without transitional forms to indicate ancestry, and both groups were rich in diversity and were widespread throughout the Eocene. The last branch to develop were the adapiforms, a diverse and widespread group that thrived during the Eocene (56 to 34 million years ago [ mya ]) in Europe, North America, and Asia. They disappeared from most of the Northern Hemisphere as
7980-459: The general term "strepsirrhine", along with oversimplified anatomical comparisons and vague phylogenetic inferences, can lead to misconceptions about primate phylogeny and misunderstandings about primates from the Eocene, as seen with the media coverage of Darwinius . Because the skeletons of adapiforms share strong similarities with those of lemurs and lorises, researchers have often referred to them as "primitive" strepsirrhines, lemur ancestors, or
8094-411: The genus Lemur into two genera: Prosimia for the lemurs, colugos, and tarsiers and Tardigradus for the lorises. Ten years later, É. Geoffroy and Georges Cuvier grouped the tarsiers and galagos due to similarities in their hindlimb morphology , a view supported by German zoologist Johann Karl Wilhelm Illiger , who placed them in the family Macrotarsi while placing the lemurs and tarsiers in
8208-426: The group, ability of site to provide protection, ease of access to the site and availability of site with respect to daily routines. While night monkeys are an arboreal species, nests have not been observed in higher strata of the rainforest ecosystem, rather a higher density of nests were recorded at low-mid vegetation levels. Night monkeys represent a territorial species, territories are defended by conspecifics through
8322-409: The high degree of paternal care which is exhibited by these primates. After the birth of an infant, males are the primary carrier of the infant, carrying offspring up to 90% of the time. In addition to aiding in child care, males will support females during lactation through sharing their foraged food with lactating females. Generally, food sharing is not observed in nature as the search for food requires
8436-412: The hottest points of the day, night monkeys are resting and therefore expending less energy in the form of heat. As they carefully construct their nests, night monkeys also benefit from the shade provided by the forest canopy which enables them to cool their bodies through the act of displacing themselves into a shady area. Additionally, finding food is energetically costly and completing this process during
8550-441: The identification of individuals within a species, increased sample size, more detailed dispersal and range patterns, but also facilitates educational programs which raise awareness for the current biodiversity crisis. The usage of radio-collaring while potentially extremely valuable, has been shown to interfere with social group interactions, the development of better collaring techniques and technology will therefore be imperative in
8664-428: The infraorder Lemuriformes (or superfamily Lemuroidea). The first fossil primate described was the adapiform Adapis parisiensis by French naturalist Georges Cuvier in 1821, who compared it to a hyrax (" le Daman "), then considered a member of a now obsolete group called pachyderms . It was not recognized as a primate until it was reevaluated in the early 1870s. Originally, adapiforms were all included under
8778-431: The lemuriform divergence from the other primates and the subsequent lemur-lorisoid split both predate the appearance of adapiforms in the early Eocene. New calibration methods may reconcile the discrepancies between the molecular clock and the fossil record, favoring more recent divergence dates. The fossil record suggests that the strepsirrhine adapiforms and the haplorhine omomyiforms had been evolving independently before
8892-585: The lemurs diversified and filled the niches often filled by monkeys and apes today. In Africa, the lorises and galagos diverged during the Eocene, approximately 40 mya. Unlike the lemurs in Madagascar, they have had to compete with monkeys and apes, as well as other mammals. The taxonomy of strepsirrhines is controversial and has a complicated history. Confused taxonomic terminology and oversimplified anatomical comparisons have created misconceptions about primate and strepsirrhine phylogeny , illustrated by
9006-407: The lemurs of Madagascar, are often portrayed inappropriately as " living fossils " or as examples of " basal ", or "inferior" primates. These views have historically hindered the understanding of mammalian evolution and the evolution of strepsirrhine traits, such as their reliance on smell ( olfaction ), characteristics of their skeletal anatomy, and their brain size, which is relatively small. In
9120-406: The lunar cycle has a significant influence on the foraging and a nocturnal behaviors of night monkey species. Night monkeys are socially monogamous—they form a bond and mate with one partner. They live in small groups consisting of a pair of reproductive adults, one infant and one to two juveniles. These species exhibit mate guarding, a practice in which the male individual will protect the female he
9234-405: The media attention surrounding the single "Ida" fossil in 2009. Strepsirrhine primates were first grouped under the genus Lemur by Swedish taxonomist Carl Linnaeus in the 10th edition of Systema Naturae published in 1758. At the time, only three species were recognized, one of which (the colugo) is no longer recognized as a primate. In 1785, Dutch naturalist Pieter Boddaert divided
9348-408: The members of this family which subsequently resulted in the alteration of their circadian rhythm to adapt to fill empty niches. Being active in the night rather than during the day time, gave Aotus access to better food sources, provided protection from predators, reduced interspecific competition and provided an escape from the harsh environmental conditions of their habitat. To begin, resting during
9462-401: The most ancestral traits , so it is often considered a sister group or stem group of the other adapiforms. Adapiforms are often divided into three major groups: The relationship between adapiform and lemuriform primates has not been clearly demonstrated, so the position of adapiforms as a paraphyletic stem group is questionable. Both molecular clock data and new fossil finds suggest that
9576-551: The most recent common ancestor of the extant species has a 95% credible interval of 27 million years ago - 31 million years ago . The following is the listing of the various platyrrhine families, as defined by Rylands & Mittermeier (2009), and their position in the Order Primates: The arrangement of the New World monkey families, indeed the listing of which groups consist of families and which consist of lower taxonomic groupings, has changed over
9690-431: The muzzle and the sternum. The process of scent marking is accomplished through the rubbing of the hairs covering scent glands onto the desired “marked item”. Olfactory cues are also of significant importance in the process of mating and mate guarding. Male night monkeys will rub subcaudal glands onto their female partner in a process called “partner marking” in order to relay the signal to coexisting males that
9804-564: The need for further research into the solution before implementation. Night monkeys are additionally threatened by both national and international trade for bushmeat and domestic pets. Since 1975, the pet trade of night monkeys has been regulated by CITES (the Convention on International Trade in Endangered Species). In the last forty years, nearly 6,000 live night monkeys and more than 7,000 specimens have been traded from
9918-519: The nine countries which they call home. While the restrictive laws put into place by CITES are aiding in the reduction of these numbers, 4 out of 9 countries, show deficiencies in maintaining the standards outlined by CITES Increased attention and enforcement of these laws will be imperative for the sustainability of night monkey populations. Use in biomedical research poses another threat to night monkey biodiversity. Species such as Nancy Ma's night monkey , like human beings, are susceptible to infection by
10032-467: The nose and reinstated the use of the suborder Strepsirrhini, while also moving the tarsiers and the simians into a new suborder, Haplorhini. It was not until 1953, when British anatomist William Charles Osman Hill wrote an entire volume on strepsirrhine anatomy, that Pocock's taxonomic suggestion became noticed and more widely used. Since then, primate taxonomy has shifted between Strepsirrhini-Haplorhini and Prosimii-Anthropoidea multiple times. Most of
10146-483: The oldest known lemuriforms had come from the early Miocene (~20 mya) of Kenya and Uganda . These newer finds demonstrate that lemuriform primates were present during the middle Eocene in Afro-Arabia and that the lemuriform lineage and all other strepsirrhine taxa had diverged before then. Djebelemur from Tunisia dates to the late early or early middle Eocene (52 to 46 mya) and has been considered
10260-406: The only extant superfamily in the parvorder Platyrrhini ( / p l æ t ɪ ˈ r aɪ n aɪ / ). Platyrrhini is derived from the Greek for "broad nosed", and their noses are flatter than those of other simians, with sideways-facing nostrils. Monkeys in the family Atelidae, such as the spider monkey , are the only primates to have prehensile tails . New World monkeys' closest relatives are
10374-449: The only truly nocturnal monkeys with the exception of some cathemeral populations of Azara's night monkey , who have irregular bursts of activity during day and night. They have a varied repertoire of vocalisations and live in small family groups of a mated pair and their immature offspring. Night monkeys have monochromatic vision which improves their ability to detect visual cues at night. Night monkeys are threatened by habitat loss,
10488-519: The other simians , the Catarrhini ("down-nosed"), comprising Old World monkeys and apes . New World monkeys descend from African simians that colonized South America, a line that split off about 40 million years ago. About 40 million years ago, the Simiiformes infraorder split into the parvorders Platyrrhini (New World monkeys) and Catarrhini (apes and Old World monkeys ) somewhere on
10602-445: The other new world monkey species. It is therefore likely that increased olfaction capacities improved the fitness of these nocturnal primate species; they produced more offspring and passed on these survival enhancing traits. The benefits of increased olfaction in night monkeys are twofold; increased ability to use scent cues has facilitated night time foraging and is also an important factor in mate selection and sexual attractivity. As
10716-523: The other prosimians. Tarsiers are most often placed in either the suborder Haplorhini with the simians or in the suborder Prosimii with the strepsirrhines. Prosimii is one of the two traditional primate suborders and is based on evolutionary grades (groups united by anatomical traits) rather than phylogenetic clades, while the Strepsirrhini-Haplorrhini taxonomy was based on evolutionary relationships. Yet both systems persist because
10830-661: The pet trade, hunting for bushmeat, and by biomedical research . They constitute one of the few monkey species affected by the often deadly human malaria protozoan Plasmodium falciparum and are therefore used as experimental subjects in malaria research. The Peruvian night monkey is classified by the International Union for Conservation of Nature (IUCN) as an Endangered species , while four are Vulnerable species , four are Least-concern species , and two are data deficient. Until 1983, all night monkeys were placed into only one ( A. lemurimus ) or two species ( A. lemurinus and A. azarae ). Chromosome variability showed that there
10944-416: The preferred taxonomic division. Yet tarsiers still closely resemble both strepsirrhines and simians in different ways, and since the early split between strepsirrhines, tarsiers and simians is ancient and hard to resolve, a third taxonomic arrangement with three suborders is sometimes used: Prosimii, Tarsiiformes, and Anthropoidea. More often, the term "prosimian" is no longer used in official taxonomy, but
11058-427: The presence of a tumescence, to determine female reproductive state. Therefore, olfactory communication in night monkeys is a result of sexual selection; sexually dimorphic trait conferring increased reproductive success. This trait demonstrates sexual dimorphism, as males have larger subcaudal scent glands compared to female counterparts and sex differences have been recorded in the glandular secretions of each sex. There
11172-524: The primates to suspend their entire body weight by only their tails, with arms and legs free for other foraging and locomotive activities. Semi-prehensile tails in Cebus can be used for balance by wrapping the tail around branches and supporting a large portion of their weight. New World monkeys (except for the howler monkeys of genus Alouatta ) also typically lack the trichromatic vision of Old World monkeys. Colour vision in New World primates relies on
11286-401: The prosimians and diurnal primate species, however the ability to use auditory cues remains more similar to diurnal primate species than to nocturnal primate species. This provides further evidence to support the hypothesis that nocturnality is a derived trait in the family Aotidae . As the ancestor of Aotidae was likely diurnal, selective and environmental pressures must have been exerted on
11400-478: The realisation and successful use of radio collars on night monkeys. New World monkey Incertae sedis New World monkeys are the five families of primates that are found in the tropical regions of Mexico , Central and South America : Callitrichidae , Cebidae , Aotidae , Pitheciidae , and Atelidae . The five families are ranked together as the Ceboidea ( / s ə ˈ b ɔɪ d i . ə / ),
11514-532: The recently extinct giant lemurs of Madagascar, many of which died out within the last 1,000 years following human arrival on the island. When Strepsirrhini is divided into two infraorders, the clade containing all toothcombed primates can be called "lemuriforms". When it is divided into three infraorders, the term "lemuriforms" refers only to Madagascar's lemurs, and the toothcombed primates are referred to as either "crown strepsirrhines" or "extant strepsirrhines". Confusion of this specific terminology with
11628-411: The relationship between tarsiers and simians as a haplorhine clade is the shared possession of three SINE markers . Because of their historically mixed assemblages which included tarsiers and close relatives of primates, both Prosimii and Strepsirrhini have been considered wastebasket taxa for "lower primates". Regardless, the strepsirrhine and haplorrhine clades are generally accepted and viewed as
11742-646: The ripeness of fruits and is therefore an important component in the optimal foraging methods of these primates. Upon finding a rich food source, night monkeys have been observed scent marking not only the food source, but the route from their sleeping site to the food source as well. Scent can therefore be used as an effective method of navigation and reduce energy expenditure during subsequent foraging expeditions. Night monkeys possess several scent glands covered by greasy hair patches, which secrete pheromones that can be transferred onto vegetation or other conspecifics. Scent glands are often located subcaudal, but also occur near
11856-441: The second "r" from both ("Strepsi r hini" and "Haplo r hini" instead of "Strepsi rr hini" and "Haplo rr hini"), although he did not remove the second "r" from Platyrrhini or Catarrhini, both of which were also named by É. Geoffroy in 1812. Following Pocock, many researchers continued to spell Strepsirrhini with a single "r" until primatologists Paulina Jenkins and Prue Napier pointed out the error in 1987. Strepsirrhines include
11970-447: The species fitness, the proximate causes of nocturnality are linked to the environmental effects on circadian rhythm. While diurnal species are stimulated by the appearance of the sun, in nocturnal species, activity is highly impacted by the degree of moon light available. The presence of a new moon has correlated with inhibition of activity in night monkeys who exhibit lower levels of activity with decreasing levels of moon light. Therefore,
12084-403: The suborder Lemuroidea contained the families Lemuridae (lemurs, lorises, and galagos), Chiromyidae ( aye-aye ), and Tarsiidae (tarsiers). Lemuroidea was later replaced by Illiger's suborder Prosimii. Many years earlier, in 1812, É. Geoffroy first named the suborder Strepsirrhini, in which he included the tarsiers. This taxonomy went unnoticed until 1918, when Pocock compared the structure of
12198-421: The survival of the infant and reduces the metabolic costs on the female. Adults will occasionally be evicted from the group by same-sex individuals, either kin or outsiders. The family Aotidae is the only family of nocturnal species within the suborder Anthropoidea. While the order primates is divided into prosimians; many of which are nocturnal, the anthropoids possess very few nocturnal species and therefore it
12312-438: The taxa otherwise considered subspecies of A. lemurinus – brumbacki , griseimembra and zonalis – should be considered separate species, whereas A. hershkovitzi arguably is a junior synonym of A. lemurinus . A new species from the gray-necked group was recently described as A. jorgehernandezi . As is the case with some other splits in this genus, an essential part of the argument for recognizing this new species
12426-555: The technique used by night monkeys in insect capturing is to use the palm of the hand to flatten a prey insect against a tree branch and then proceed to consume the carcass. During the winter months or when food sources are reduced, night monkeys have also been observed foraging on flowers such as Tabebuia heptaphylla , however this does not represent a primary food source. In night monkeys, mating occurs infrequently, however females are fertile year-round, with reproductive cycles range from 13 to 25 days. The gestation period for night monkey
12540-590: The use of threatening and agonistic behaviours. Ranges between night monkey species often do overlap and result in interspecific aggressions such as vocalizing and chasing which may last up to an hour. Night monkeys are primarily frugivorous , as fruits are easily distinguished through the use of olfactory cues, but leaf and insect consumption has also been observed in the cathemeral night monkey species A. azare . A study conducted by Wolovich et al., indicated that juveniles and females were much better at catching both crawling and flying insects than adult males. In general,
12654-810: The years. McKenna & Bell (1997) used two families: Callitrichidae and Atelidae, with Atelidae divided into Cebinae, Pitheciinae, and Atelinae. Rosenberger (2002 following Horowitz 1999) demoted Callitrichidae to a subfamily, putting it under the newly raised Cebidae family. Groves (2005) used four families, but as a flat structure. One possible arrangement of the five families and their subfamilies of Rylands & Mittermeier can be seen in Silvestro et al. (2017): titis sakis and uakaris howler monkeys spider, woolly spider, and woolly monkeys capuchins squirrel monkeys marmosets and lion tamarins tamarins and saddle-back tamarins night monkeys New World monkeys are small to mid-sized primates, ranging from
12768-454: Was differences in the chromosomes . Chromosome evidence has also been used as an argument for merging "species", as was the case for considering infulatus a subspecies of A. azarae rather than a separate species. One extinct species is known from the fossil record. Family Aotidae Night monkeys have large brown eyes; the size improves their nocturnal vision increasing their ability to be active at night. They are sometimes said to lack
12882-541: Was identified as cercamoniines, which were allied with the notharctids found mostly in North America, while the other group falls into the traditional adapid classification. The three major adapiform divisions are now typically regarded as three families within Adapiformes (Notharctidae, Adapidae and Sivaladapidae), but other divisions ranging from one to five families are used as well. All lemuriforms possess
12996-446: Was more than one species in the genus and Hershkovitz (1983) used morphological and karyological evidence to propose nine species, one of which is now recognised as a junior synonym . He split Aotus into two groups: a northern, gray-necked group ( A. lemurinus , A. hershkovitzi , A. trivirgatus and A. vociferans ) and a southern, red-necked group ( A. miconax , A. nancymaae , A. nigriceps and A. azarae ). Arguably,
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