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Edward E. Louis - One of the best experts on this subject based on the ideXlab platform.
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locomotion of an adult female and juvenile male aye aye Daubentonia madagascariensis in torotorofotsy madagascar
American Journal of Primatology, 2021Co-Authors: Timothy M. Sefczek, Scott W Mcgraw, David M Faralahy, Gabriel M Manampisoa, Edward E. LouisAbstract:Aye-ayes (Daubentonia madagascariensis) locate and acquire invertebrates from within woody substrates at all levels of the rainforest; yet how their locomotion helps them accommodate this diet has not been explored in detail. We studied the locomotor behavior of an adult female (N = 1,085) and juvenile male (N = 708) aye-aye in the undisturbed forest of Torotorofotsy, Madagascar from May to December 2017. We used bout sampling to record locomotion during foraging and travel of the two radio-collared individuals. We used χ 2 tests to compare overall locomotion, travel, and foraging, as well as strata and support use. We performed a correspondence analysis to examine relationships between individual behaviors, strata, and support types. Leaping accounted for 47.9% and 50.1% of all locomotor activity in the adult female and juvenile male, respectively. Leaping was the most common behavior during travel in both individuals (59.2% and 53.9%, respectively), whereas head-first descent was most frequent during foraging (35.0% and 48.0%, respectively). For all three locomotor categories, the main canopy (40.3%-79.6%) was used most frequently and trunks were the most frequently used support type (50.7%-60.0%). There is a strong association between strata and support use overall and during travel. Quadrupedal walking was significantly associated with the main canopy, as was head-first descent with the low canopy. Our analysis demonstrates that aye-ayes use a variety of locomotor behaviors to forage for invertebrates. Aye-ayes' ability to repurpose their positional repertoire to acquire other resources in degraded forests should not obscure the importance of invertebrates to this species.
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Developmental Timeline of Wild Aye-Aye (Daubentonia madagascariensis) Infants in Kianjavato and Torotorofotsy, Madagascar
International Journal of Primatology, 2021Co-Authors: Jeannin Nicolas Rakotondrazandry, Faranky Ravelomandrato, Timothy M. Sefczek, Yves Rostant Andriamalala, Cynthia L. Frasier, Vicki L. Villanova, Solofonirina Rasoloharijaona, Herimalala Raveloson, Edward E. LouisAbstract:Wild aye-ayes ( Daubentonia madagascariensis ) are notoriously difficult to study due to their solitary and nocturnal nature. While research is starting to elucidate the behaviors of wild adult aye-aye, an understanding of behaviors in young aye-ayes is still lacking. We studied the behavioral development of two male aye-aye subadults in Kianjavato, Madagascar from June 2015 to October 2017 and October 2017 to December 2019, and two male offspring in Torotorofotsy, Madagascar, from August 2016 to December 2017 and September 2018 to May 2020. We then compared this information to previous studies on captive infant development. Wild infant aye-ayes first emerged from the nest between two and three months old. Traveling between trees occurred between four and four and a half months old. First attempts at foraging for invertebrates in a woody substrate occurred between five and eight months. Though nursing was rarely observed, the event was witnessed as late as 17 months for one aye-aye. The earliest solo nesting occurred at 18 and a half months of age, and the latest at 23 months old. As with other primates, wild aye-ayes develop more slowly than their captive counterparts. We conclude that their protracted life history is likely associated with their percussive foraging behaviors and importance of invertebrates in their diet.
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possible infanticidal event of an aye aye Daubentonia madagascariensis in torotorofotsy madagascar
Folia Primatologica, 2021Co-Authors: Jeannin Nicolas Rakotondrazandry, Timothy M. Sefczek, Cynthia L. Frasier, Vicki L. Villanova, Solofonirina Rasoloharijaona, Herimalala Raveloson, Edward E. LouisAbstract:Infanticide occurs in an array of mammalian species, especially primates. Most infanticidal events occur in polygynous societies, though they sometimes happen in nongregarious populations. We witnessed a possible infanticidal event of a 3-month-old male aye-aye, a species that exhibits a dispersed multimale social system, in Torotorofotsy, Madagascar. Though firsthand killing of the infant was not observed, physical injuries to the infant, vocalizations of the adult female, and her subsequent chase of the adult male aye-aye strongly indicates infanticide. If true, this would be the first recorded incident of an infanticidal event in a noyau primate. The evidence for three different explanations of infanticide is evaluated.
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home range size and seasonal variation in habitat use of aye ayes Daubentonia madagascariensis in torotorofotsy madagascar
Folia Primatologica, 2020Co-Authors: Timothy M. Sefczek, Jeannin Nicolas Rakotondrazandry, Domenico Roger Randimbiharinirina, Ryan A Hagenson, Edward E. LouisAbstract:Madagascar's dramatic climatic fluctuations mean most lemurs adjust behaviors seasonally as resource availability fluctuates. Many lemurs will adopt one of two strategies, a resource maximizer or an area minimizer, when adjusting to seasonal shifts in resource availability. However, it is unknown if and how aye-aye (Daubentonia madagascariensis) ranging behavior is influenced by seasonality. We explored whether habitat use changed seasonally. We followed two aye-ayes, an adult male and an adult female, in the undisturbed forest of Torotorofotsy, Madagascar, from April 2012 to December 2017. We used instantaneous focal-animal sampling to collect behavioral data every 5 min and GPS locations every 20 min. We used the minimum convex polygon (MCP) to determine overall home range, and the Brownian bridge movement model (BBMM) to estimate overall and seasonal home range of the female aye-aye from November 2014 to October 2017. We used Wilcoxon signed-rank tests to determine whether there were significant differences in home range sizes between seasons across years and to examine whether there were seasonal differences in height of invertebrate foraging, generalized linear models to assess seasonal differences in travel rates and nesting locations, and χ2 tests to determine whether there were differences in forest strata use when foraging on invertebrates. The male's MCP home range was 2,586 ha, and the female's MCP home range was 765 ha. The seasonal BBMM for the female varied between 443.6 and 1,010.0 ha, though infant rearing appears to have influenced these values. There were no significant differences in seasonal home range, travel rates, nesting locations, or height of invertebrate feeding. However, canopy level invertebrate foraging occurred more often than understory or ground levels. It appears aye-ayes in this undisturbed forest were not influenced by seasonal shifts and had larger home ranges than any previously reported. These findings may indicate that aye-ayes in an undisturbed forest are resource maximizers, closely linked to invertebrate assemblages.
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re assessing the applicability of the jarman bell model and kay s threshold to the insectivorous aye aye Daubentonia madagascariensis
American Journal of Physical Anthropology, 2020Co-Authors: Timothy M. Sefczek, Domenico Roger Randimbiharinirina, Brigitte M Raharivololona, Harison Razafimahaleo, Olivier Randrianarison, Edward E. LouisAbstract:OBJECTIVES Jarman/Bell principle and Kay's threshold suggest that large animals should not be able to sustain themselves on insects. However, animals with specialized morphological and/or behavioral adaptations violate these assumptions. Male aye-ayes were recently identified as having an insectivorous diet despite weighing 2.5 kg. We further explored this diet/body size disparity by studying behaviors of an adult female and juvenile male aye-aye. MATERIALS AND METHODS We collected behavioral data on an adult female and juvenile male aye-aye in Torotorofotsy, Madagascar from January 2016 to December 2017. We used instantaneous sampling to determine the frequency of feeding events and continuous sampling during feeding behaviors to assess duration of feeding bouts. RESULTS Invertebrates comprised over 88% of the diet for both animals. A Wilcoxon signed-rank test found no significant difference in the female's feeding frequencies between the hot/rainy seasons and the cold/dry seasons. DISCUSSION Our results support earlier findings that invertebrates are the aye-aye's main resource and corroborate that aye-ayes violate assumptions of the Jarman/Bell model and Kay's threshold. We suggest that the Jarman/Bell principle and Kay's threshold be used as supporting evidence and not to repudiate findings that do not conform to these guidelines.
Timothy M. Sefczek - One of the best experts on this subject based on the ideXlab platform.
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locomotion of an adult female and juvenile male aye aye Daubentonia madagascariensis in torotorofotsy madagascar
American Journal of Primatology, 2021Co-Authors: Timothy M. Sefczek, Scott W Mcgraw, David M Faralahy, Gabriel M Manampisoa, Edward E. LouisAbstract:Aye-ayes (Daubentonia madagascariensis) locate and acquire invertebrates from within woody substrates at all levels of the rainforest; yet how their locomotion helps them accommodate this diet has not been explored in detail. We studied the locomotor behavior of an adult female (N = 1,085) and juvenile male (N = 708) aye-aye in the undisturbed forest of Torotorofotsy, Madagascar from May to December 2017. We used bout sampling to record locomotion during foraging and travel of the two radio-collared individuals. We used χ 2 tests to compare overall locomotion, travel, and foraging, as well as strata and support use. We performed a correspondence analysis to examine relationships between individual behaviors, strata, and support types. Leaping accounted for 47.9% and 50.1% of all locomotor activity in the adult female and juvenile male, respectively. Leaping was the most common behavior during travel in both individuals (59.2% and 53.9%, respectively), whereas head-first descent was most frequent during foraging (35.0% and 48.0%, respectively). For all three locomotor categories, the main canopy (40.3%-79.6%) was used most frequently and trunks were the most frequently used support type (50.7%-60.0%). There is a strong association between strata and support use overall and during travel. Quadrupedal walking was significantly associated with the main canopy, as was head-first descent with the low canopy. Our analysis demonstrates that aye-ayes use a variety of locomotor behaviors to forage for invertebrates. Aye-ayes' ability to repurpose their positional repertoire to acquire other resources in degraded forests should not obscure the importance of invertebrates to this species.
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Developmental Timeline of Wild Aye-Aye (Daubentonia madagascariensis) Infants in Kianjavato and Torotorofotsy, Madagascar
International Journal of Primatology, 2021Co-Authors: Jeannin Nicolas Rakotondrazandry, Faranky Ravelomandrato, Timothy M. Sefczek, Yves Rostant Andriamalala, Cynthia L. Frasier, Vicki L. Villanova, Solofonirina Rasoloharijaona, Herimalala Raveloson, Edward E. LouisAbstract:Wild aye-ayes ( Daubentonia madagascariensis ) are notoriously difficult to study due to their solitary and nocturnal nature. While research is starting to elucidate the behaviors of wild adult aye-aye, an understanding of behaviors in young aye-ayes is still lacking. We studied the behavioral development of two male aye-aye subadults in Kianjavato, Madagascar from June 2015 to October 2017 and October 2017 to December 2019, and two male offspring in Torotorofotsy, Madagascar, from August 2016 to December 2017 and September 2018 to May 2020. We then compared this information to previous studies on captive infant development. Wild infant aye-ayes first emerged from the nest between two and three months old. Traveling between trees occurred between four and four and a half months old. First attempts at foraging for invertebrates in a woody substrate occurred between five and eight months. Though nursing was rarely observed, the event was witnessed as late as 17 months for one aye-aye. The earliest solo nesting occurred at 18 and a half months of age, and the latest at 23 months old. As with other primates, wild aye-ayes develop more slowly than their captive counterparts. We conclude that their protracted life history is likely associated with their percussive foraging behaviors and importance of invertebrates in their diet.
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possible infanticidal event of an aye aye Daubentonia madagascariensis in torotorofotsy madagascar
Folia Primatologica, 2021Co-Authors: Jeannin Nicolas Rakotondrazandry, Timothy M. Sefczek, Cynthia L. Frasier, Vicki L. Villanova, Solofonirina Rasoloharijaona, Herimalala Raveloson, Edward E. LouisAbstract:Infanticide occurs in an array of mammalian species, especially primates. Most infanticidal events occur in polygynous societies, though they sometimes happen in nongregarious populations. We witnessed a possible infanticidal event of a 3-month-old male aye-aye, a species that exhibits a dispersed multimale social system, in Torotorofotsy, Madagascar. Though firsthand killing of the infant was not observed, physical injuries to the infant, vocalizations of the adult female, and her subsequent chase of the adult male aye-aye strongly indicates infanticide. If true, this would be the first recorded incident of an infanticidal event in a noyau primate. The evidence for three different explanations of infanticide is evaluated.
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home range size and seasonal variation in habitat use of aye ayes Daubentonia madagascariensis in torotorofotsy madagascar
Folia Primatologica, 2020Co-Authors: Timothy M. Sefczek, Jeannin Nicolas Rakotondrazandry, Domenico Roger Randimbiharinirina, Ryan A Hagenson, Edward E. LouisAbstract:Madagascar's dramatic climatic fluctuations mean most lemurs adjust behaviors seasonally as resource availability fluctuates. Many lemurs will adopt one of two strategies, a resource maximizer or an area minimizer, when adjusting to seasonal shifts in resource availability. However, it is unknown if and how aye-aye (Daubentonia madagascariensis) ranging behavior is influenced by seasonality. We explored whether habitat use changed seasonally. We followed two aye-ayes, an adult male and an adult female, in the undisturbed forest of Torotorofotsy, Madagascar, from April 2012 to December 2017. We used instantaneous focal-animal sampling to collect behavioral data every 5 min and GPS locations every 20 min. We used the minimum convex polygon (MCP) to determine overall home range, and the Brownian bridge movement model (BBMM) to estimate overall and seasonal home range of the female aye-aye from November 2014 to October 2017. We used Wilcoxon signed-rank tests to determine whether there were significant differences in home range sizes between seasons across years and to examine whether there were seasonal differences in height of invertebrate foraging, generalized linear models to assess seasonal differences in travel rates and nesting locations, and χ2 tests to determine whether there were differences in forest strata use when foraging on invertebrates. The male's MCP home range was 2,586 ha, and the female's MCP home range was 765 ha. The seasonal BBMM for the female varied between 443.6 and 1,010.0 ha, though infant rearing appears to have influenced these values. There were no significant differences in seasonal home range, travel rates, nesting locations, or height of invertebrate feeding. However, canopy level invertebrate foraging occurred more often than understory or ground levels. It appears aye-ayes in this undisturbed forest were not influenced by seasonal shifts and had larger home ranges than any previously reported. These findings may indicate that aye-ayes in an undisturbed forest are resource maximizers, closely linked to invertebrate assemblages.
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re assessing the applicability of the jarman bell model and kay s threshold to the insectivorous aye aye Daubentonia madagascariensis
American Journal of Physical Anthropology, 2020Co-Authors: Timothy M. Sefczek, Domenico Roger Randimbiharinirina, Brigitte M Raharivololona, Harison Razafimahaleo, Olivier Randrianarison, Edward E. LouisAbstract:OBJECTIVES Jarman/Bell principle and Kay's threshold suggest that large animals should not be able to sustain themselves on insects. However, animals with specialized morphological and/or behavioral adaptations violate these assumptions. Male aye-ayes were recently identified as having an insectivorous diet despite weighing 2.5 kg. We further explored this diet/body size disparity by studying behaviors of an adult female and juvenile male aye-aye. MATERIALS AND METHODS We collected behavioral data on an adult female and juvenile male aye-aye in Torotorofotsy, Madagascar from January 2016 to December 2017. We used instantaneous sampling to determine the frequency of feeding events and continuous sampling during feeding behaviors to assess duration of feeding bouts. RESULTS Invertebrates comprised over 88% of the diet for both animals. A Wilcoxon signed-rank test found no significant difference in the female's feeding frequencies between the hot/rainy seasons and the cold/dry seasons. DISCUSSION Our results support earlier findings that invertebrates are the aye-aye's main resource and corroborate that aye-ayes violate assumptions of the Jarman/Bell model and Kay's threshold. We suggest that the Jarman/Bell principle and Kay's threshold be used as supporting evidence and not to repudiate findings that do not conform to these guidelines.
Carl J Erickson - One of the best experts on this subject based on the ideXlab platform.
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percussive foraging stimuli for prey location by aye ayes Daubentonia madagascariensis
International Journal of Primatology, 1998Co-Authors: Carl J Erickson, Stephen Nowicki, Luke Dollar, Nathan W GoehringAbstract:Aye-ayes (Daubentonia madagascariensis) use the thin middle finger to tap on wood in search of subsurface cavities containing insect larvae. When a cavity is located, they gnaw away wood until the prey can be extracted. Previous researchers suggested that acoustical cues reveal cavity location. We designed five studies to identify the cavity features that provide acoustical cues. When cavities were backfilled with gelatin or acoustical foam, excavation was still successful, suggesting that the reverberation of sound in air-filled cavities is not necessary for detection. Moreover, when the density of cavity content was varied, there was no difference in excavation frequency. On the other hand, a one-dimensional break in the subsurface wood was an effective stimulus for excavation. These studies suggest that a simple interface beneath the surface is sufficient to elicit excavation and that neither prey nor cavity nor even small air pockets are necessary to elicit the behavior. These results raise provocative questions as to how the aye-aye manages to forage efficiently.
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feeding sites for extractive foraging by the aye aye Daubentonia madagascariensis
American Journal of Primatology, 1995Co-Authors: Carl J EricksonAbstract:The aye-aye, Daubentonia madagascariensis, uses its middle digit to tap on woody sources in search of subsurface cavities containing prey. The acoustical properties of these cavities are thought to be important to this percussive foraging, but the contributions of cavity size, configuration, and contents to efficient prey capture are not known. The purpose of this study was to characterize these cavities and their residents. An analysis of foraged trees at two sites in Madagascar revealed that many of the foraged cavities are mines bored by large cerambycid beetle larvae. Apparently cerambycids, as well as inquiline residents of their mines, are major targets of aye-aye foraging behavior. The larvae bore extended mines that course approximately parallel to the long axes of the trees in which they reside. The orientation and large size of the mines offer an acoustical trail that the aye-aye may follow to its prey. © 1995 Wiley-Liss, Inc.
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perspectives on percussive foraging in the aye aye Daubentonia madagascariensis
1995Co-Authors: Carl J EricksonAbstract:In 1858 Richard Owen learned that H.M. Sandwith would be traveling to Mauritius as the new Colonial Secretary. He urged Sandwith to visit neighboring Madagascar and bring back an aye-aye, dead or alive. Eventually the British Museum was to receive its specimen “immersed in a keg of colourless spirit” but not before Sandwith had examined the behavior of this peculiar animal in considerable detail. In March of 1859 he wrote to Owen of his observations: “......bending forward his ears, and applying his nose close to the bark, he rapidly tapped the surface with the curious second (sic) digit, as a Woodpecker taps a tree, though with much less noise, from time to time inserting the slender finger into the wormholes as a surgeon would a probe.....I watched these proceedings with intense interest, and was much struck with the marvellous adaptation of the creature to its habits, shown by his acute hearing, which enables him aptly to distinguish the different tones emitted from the wood by his gentle tapping; his evidently acute sense of smell, aiding him in his search; ....the curious slender finger, unlike that of any other animal... he used alternately as a pleximeter, a probe, and a scoop.” (Owen, 1866; p. 38).
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tap scanning and extractive foraging in aye ayes Daubentonia madagascariensis
Folia Primatologica, 1994Co-Authors: Carl J EricksonAbstract:The trees on which aye-ayes forage contain complex communities of organisms. Aye-ayes appear to use tap-scanning behaviour, in combination with complex perceptual and inferential capabilities, to exploit these communities as a source of food. In doing so, they alter them, perhaps to their own advantage.
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percussive foraging in the aye aye Daubentonia madagascariensis
Animal Behaviour, 1991Co-Authors: Carl J EricksonAbstract:Abstract A series of studies is described in which some of the sensory and motor capabilities used by the aye-aye, Daubentonia madagascariensis , in foraging for insect larvae are delineated. Although visual and olfactory cues may be of some aid, they are not necessary for successful location of larvae within woody sources. Rather, the aye-aye gently taps on wood surfaces to determine the location of cavities. Although the aye-aye can accurately locate cavities that contain no larvae or those containing inactive prey, significantly more cavities are opened when they contain active larvae. These observations suggest that this primate uses echolocation or a cutaneous sense to find cavities and can also detect the movements of insect larvae within the cavities.
Nathaniel J. Dominy - One of the best experts on this subject based on the ideXlab platform.
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alcohol discrimination and preferences in two species of nectar feeding primate
Royal Society Open Science, 2016Co-Authors: Samuel R Gochman, Michael B Brown, Nathaniel J. DominyAbstract:Recent reports suggest that dietary ethanol, or alcohol, is a supplemental source of calories for some primates. For example, slow lorises (Nycticebus coucang) consume fermented nectars with a mean alcohol concentration of 0.6% (range: 0.0-3.8%). A similar behaviour is hypothesized for aye-ayes (Daubentonia madagascariensis) based on a single point mutation (A294V) in the gene that encodes alcohol dehydrogenase class IV (ADH4), the first enzyme to catabolize alcohol during digestion. The mutation increases catalytic efficiency 40-fold and may confer a selective advantage to aye-ayes that consume the nectar of Ravenala madagascariensis. It is uncertain, however, whether alcohol exists in this nectar or whether alcohol is preferred or merely tolerated by nectarivorous primates. Here, we report the results of a multiple-choice food preference experiment with two aye-ayes and a slow loris. We conducted observer-blind trials with randomized, serial dilutions of ethanol (0-5%) in a standard array of nectar-simulating sucrose solutions. We found that both species can discriminate varying concentrations of alcohol; and further, that both species prefer the highest available concentrations. These results bolster the hypothesized adaptive function of the A294V mutation in ADH4, and a connection with fermented foods, both in aye-ayes and the last common ancestor of African apes and humans.
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receiver bias and the acoustic ecology of aye ayes Daubentonia madagascariensis
Communicative & Integrative Biology, 2012Co-Authors: Marissa Ramsier, Nathaniel J. DominyAbstract:The aye-aye is a rare lemur from Madagascar that uses its highly specialized middle digit for percussive foraging. This acoustic behavior, also termed tap-scanning, produces dominant frequencies between 6 and 15 kHz. An enhanced auditory sensitivity to these frequencies raises the possibility that the acoustic and auditory specializations of aye-ayes have imposed constraints on the evolution of their vocal signals, especially their primary long-distance vocalization, the screech. Here we explore this concept, termed receiver bias, and suggest that the dominant frequency of the screech call (~2.7 kHz) represents an evolutionary compromise between the opposing adaptive advantages of long-distance sound propagation and enhanced detection by conspecific receivers.
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Thermal Imaging of Aye-Ayes (Daubentonia madagascariensis) Reveals a Dynamic Vascular Supply During Haptic Sensation
International Journal of Primatology, 2012Co-Authors: Gillian L Moritz, Nathaniel J. DominyAbstract:Infrared thermography (IRT) is used to visualize and estimate variation in surface temperatures. Applications of IRT to animal research include studies of thermofunctional anatomy, ecology, and social behavior. IRT is especially amenable to investigations of the somatosensory system because touch receptors are highly vascularized, dynamic, and located near the surface of the skin. The hands of aye-ayes ( Daubentonia madagascariensis ) are thus an inviting subject for IRT because of the prominent middle digit that functions as a specialized haptic sense structure during percussive and probative foraging. It is a vital sensory tool that is expected to feature a high density of dermal mechanoreceptors that radiate heat and impose thermal costs under cool temperatures. Here we explore this premise by acquiring IRT images of 8 aye-ayes engaged in a variety of passive and probative behaviors. We found that the middle digit was typically 2.3°C cooler than other digits when the metacarpophalangeal (MP) joint was extended, and that it warmed an average of 2.0°C when the MP joint was flexed during active touching behavior. These changes in digital surface temperature, which were sometimes as much 6.0°C, stand in sharp contrast with the profoundly invariant temperatures of the other digits. Although the physiological mechanisms behind these temperature changes are unknown, they appear to reveal a uniquely dynamic vascular supply.
Stanislav Lhota - One of the best experts on this subject based on the ideXlab platform.
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patterns and laterality of hand use in free ranging aye ayes Daubentonia madagascariensis and a comparison with captive studies
Journal of Ethology, 2009Co-Authors: Stanislav Lhota, Tomas Jůnek, Luděk BartosAbstract:We observed hand use in free-ranging aye-ayes (Daubentonia madagascariensis) on an island in the Mananara River, eastern Madagascar. The results were compared with those of two conflicting studies on hand laterality in captive aye-ayes. We argue that patterns of hand preference in wild aye-ayes are comparable to those of captive animals and that discrepancies between studies are—at least partly—caused by different ways of collecting and processing data. Aye-ayes fit Level 2 of the categories of hand laterality described by McGrew and Marchant (Yearb Phys Anthropol 40:201–232, 1997), with some individuals showing significant hand preference, but with the proportion of right- to left-preferent animals being very close to 1:1. We observed hand preference to be consistent for two of the most frequent behaviors, tapping and probing with fingers. Reaching and holding objects in hands is rare in aye-ayes, and the patterns of hand use in aye-ayes are therefore not directly comparable with those of other prosimians in which laterality has been studied. We detected no effect of sex on hand preference and were unable to determine whether there is an effect of age. The posture adopted by the animals did not influence hand preference.
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specialized use of two fingers in free ranging aye ayes Daubentonia madagascariensis
American Journal of Primatology, 2008Co-Authors: Stanislav Lhota, Tomas Jůnek, Luděk Bartos, Ales KuběnaAbstract:The aye-aye (Daubentonia madagascariensis) possesses a highly specialized hand with two fingers, the third and the fourth, being used in a way unparalleled by any other primate. We observed the use of the third and the fourth fingers in various activities in four free-ranging aye-ayes. We found that the thin third finger was used exclusively or preferably for tapping, inserting into the mouth (probably for cleaning the teeth) and probing for nectar, kernels and insects in bamboo, twigs and live wood. In contrast, the robust fourth finger was used preferably when eating jackfruit (Artocarpus heterophyllus). When probing for invertebrates in soft plant tissues and in dead wood, both fingers were used in high proportions. To extract the contents from coconuts, the two fingers were apparently used for different tasks. From this small (686 observations), but unique, study of free-ranging aye-ayes, we conclude that the third finger appears to be specialized for use in tasks requiring high mobility, sensitivity and precision, whereas the fourth finger appears to be specialized for tasks requiring strength, scooping action and deep access. Am. J. Primatol. 70:786–795, 2008. © 2008 Wiley-Liss, Inc.
