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1.
Folia Primatol (Basel) ; 92(3): 183-190, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34350859

RESUMO

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.


Assuntos
Agressão , Comportamento Animal , Strepsirhini/psicologia , Animais , Madagáscar , Masculino
2.
Zool Res ; 42(4): 428-432, 2021 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-34114756

RESUMO

Accurate information on name-bearing types, including corresponding type localities, is essential for proper taxonomy. However, such geographic information is often missing or unreliable. The localities of type specimens collected 100-200 years ago can be difficult to trace due to changes in local names or simple inaccuracies. Such a case can be found for the gray-backed sportive lemur (Lepilemur dorsalis), with its type locality imprecisely fixed as Northwest Madagascar. In recent years, eight species have been newly described for the Inter-River-Systems (IRSs) of this region, however the designation of L. dorsalis remains controversial due to a lack of a precise type locality. Here, we sequenced the complete mitochondrial genomes (mitogenomes) of type specimens of L. dorsalis and L. grandidieri, which is currently recognized as a synonym of L. dorsalis and compared their sequences with those of samples of known provenance from different IRSs. Results showed that the two type specimens of L. dorsalis and L. grandidieri had identical mitogenome sequences and clustered closely with samples collected in IRS V, indicating that the type locality could be fixed to IRS V. Consequently, L. dorsalis occurs in IRS V, and L. grandidieri and L. mittermeieri are junior synonyms of L. dorsalis. This finding demonstrates the value of type specimens for clarifying phylogeographic and taxonomic questions and clarifies the taxonomy of sportive lemurs in Northwest Madagascar.


Assuntos
Distribuição Animal , Genoma Mitocondrial , Strepsirhini/genética , Animais , DNA Mitocondrial , Madagáscar , Filogenia , Filogeografia , Especificidade da Espécie , Strepsirhini/classificação , Strepsirhini/fisiologia
3.
Folia Primatol (Basel) ; 92(3): 139-150, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34175845

RESUMO

Traditional socio-ecological models consider that folivorous primates experience limited feeding competition due to the low quality, high abundance, and even distribution of leaves. Evidence from several folivorous species that experience similar constraints to frugivores does not support this hypothesis. The sympatric lemur genera Avahi (Indriidae) and Lepilemur (Lepilemuridae) are good models to understand how food availability constrains folivores since they are both nocturnal, folivorous, and have a comparable body mass. Here we investigate how two nocturnal folivorous primates, Avahi meridionalis and Lepilemur fleuretae, living in the lowland rain forest of Tsitongambarika, South-East Madagascar, partition their dietary niche and are influenced by seasonality of young leaves. To account for food availability, we collected annual phenological data on 769 trees from 200 species. We also collected behavioural data on 5 individuals per lemur species from August 2015 to July 2016 via continuous focal sampling. We found the phenological profile to be seasonal with peaks of leaf flushing, flowering, and fruiting occurring in the austral summer. The two species showed limited dietary overlap (37% rich period, 6% lean period), and A. meridionalis showed higher feeding time and longer daily distances travelled during the rich period. Lepilemur fleuretae showed a dietary shift during the lean period, relying more on mature leaves (73.3% during the lean period, 13.5% during the rich period) but maintaining similar activity levels between seasons. The time spent feeding on food items by A. meridionalis was positively correlated with the nitrogen content and negatively correlated with polyphenols during the rich period. We highlighted a clear effect of the seasonality of young leaves on the diet, nutritional content, activity patterns, and daily distances travelled by two folivorous species, which can be linked to nutrient balancing and time-minimising versus energy-maximising strategies.


Assuntos
Dieta/veterinária , Folhas de Planta , Strepsirhini/fisiologia , Animais , Ecossistema , Feminino , Madagáscar , Masculino , Folhas de Planta/crescimento & desenvolvimento , Estações do Ano , Especificidade da Espécie
4.
Am J Primatol ; 83(7): e23267, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33956356

RESUMO

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.


Assuntos
Comportamento Alimentar , Strepsirhini , Animais , Dieta , Feminino , Locomoção , Madagáscar , Masculino
5.
Vopr Virusol ; 66(2): 103-111, 2021 05 15.
Artigo em Russo | MEDLINE | ID: mdl-33993680

RESUMO

Due to the new coronavirus infection pandemic, the global scientific community has been forced to change the direction of the most research, focusing on vaccine development as well as the search for new antiviral drugs to treat COVID-19. The choice of experimental models, timeframe and approaches for evaluating drugs and vaccines under development is crucial for the development of effective measures to prevent and control this disease.The purpose of this review was to summarize the relevant data concerning the susceptibility of laboratory animals to SARS-CoV-2. This paper describes the most virus-susceptible animal species that can be used to reproduce coronavirus infection, stressing the main advantages and disadvantages of each of them.According to the latest data, small rodents (Rodentia) and non-human primates (Strepsirrhini) are commonly used in the scientific community to model coronavirus infection. The viral load in the upper and lower parts of the respiratory system, clinical symptoms of infection (weight loss, body temperature and general health status), pathomorphological picture in target organs and the production of antibodies after infection are considered to the main markers of pathology. Despite the vast amount of data, none of the described models of SARS-CoV-2 infection may be considered a gold standard, since they do not reproduce all spectrum of morphological and pathogenetic mechanisms of infection, and do not fully reflect the clinical picture observed in patients in human population.Based on the analyzed literature data, we suppose that Syrian hamster (Mesocricetus auratus) and mice (Muridae) expressing the angiotensin converting enzyme receptor 2 (ACE2) are the most suitable animal species for their use in experiments with SARS-CoV-2 infection. The development of neutralizing antibodies makes it possible to evaluate the efficacy of vaccines, while the course and severity of symptoms infection makes the use of mice and hamsters especially popular for screening pharmacological substances with antiviral mechanism of action, when their administration can prevent or slow the disease progression.


Assuntos
COVID-19/metabolismo , Modelos Animais de Doenças , SARS-CoV-2/metabolismo , Animais , COVID-19/epidemiologia , COVID-19/patologia , Cricetinae , Humanos , Camundongos , Pandemias , Especificidade da Espécie , Strepsirhini
6.
BMC Ecol Evol ; 21(1): 60, 2021 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-33882818

RESUMO

BACKGROUND: Lemurs once rivalled the diversity of rest of the primate order despite thier confinement to the island of Madagascar. We test the adaptive radiation model of Malagasy lemur diversity using a novel combination of phylogenetic comparative methods and geometric methods for quantifying tooth shape. RESULTS: We apply macroevolutionary model fitting approaches and disparity through time analysis to dental topography metrics associated with dietary adaptation, an aspect of mammalian ecology which appears to be closely related to diversification in many clades. Metrics were also reconstructed at internal nodes of the lemur tree and these reconstructions were combined to generate dietary classification probabilities at internal nodes using discriminant function analysis. We used these reconstructions to calculate rates of transition toward folivory per million-year intervals. Finally, lower second molar shape was reconstructed at internal nodes by modelling the change in shape of 3D meshes using squared change parsimony along the branches of the lemur tree. Our analyses of dental topography metrics do not recover an early burst in rates of change or a pattern of early partitioning of subclade disparity. However, rates of change in adaptations for folivory were highest during the Oligocene, an interval of possible forest expansion on the island. CONCLUSIONS: There was no clear phylogenetic signal of bursts of morphological evolution early in lemur history. Reconstruction of the molar morphologies corresponding to the ancestral nodes of the lemur tree suggest that this may have been driven by a shift toward defended plant resources, however. This suggests a response to the ecological opportunity offered by expanding forests, but not necessarily a classic adaptive radiation initiated by dispersal to Madagascar.


Assuntos
Lemur , Strepsirhini , Animais , Dieta , Madagáscar , Filogenia
7.
Viruses ; 13(3)2021 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-33673677

RESUMO

Studies of viruses that coevolved with lemurs provide an opportunity to understand the basal traits of primate viruses and provide an evolutionary context for host-virus interactions. Germline integration of endogenous retroviruses (ERVs) are fossil evidence of past infections. Hence, characterization of novel ERVs provides insight into the ancient precursors of extant viruses and the evolutionary history of their hosts. Here, we report the discovery of a novel endogenous retrovirus present in the genome of a lemur, Coquerel's sifaka (Propithecus coquereli). Using next-generation sequencing, we identified and characterized the complete genome sequence of a retrovirus, named prosimian retrovirus 1 (PSRV1). Phylogenetic analyses indicate that PSRV1 is a gamma-type betaretrovirus basal to the other primate betaretroviruses and most closely related to simian retroviruses. Molecular clock analysis of PSRV1 long terminal repeat (LTR) sequences estimated the time of endogenization within 4.56 MYA (± 2.4 MYA), placing it after the divergence of Propithecus species. These results indicate that PSRV1 is an important milestone of lemur evolution during the radiation of the Propithecus genus. These findings may have implications for both human and animal health in that the acquisition of a gamma-type env gene within an endogenized betaretrovirus could facilitate a cross-species jump between vertebrate class hosts.


Assuntos
Retrovirus Endógenos/genética , Lemur/virologia , Strepsirhini/virologia , Sequência de Aminoácidos , Animais , Evolução Molecular , Genoma/genética , Humanos , Filogenia
8.
Primates ; 62(3): 537-546, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33759106

RESUMO

The growing dependence of villagers on local forests (food, wood, etc.) makes the comparative assessment of the perceptions they have of the forest and its wildlife increasingly important for setting conservation priorities. While hunting and habitat loss are important threats to primates' existence worldwide, more attention has been focused on diurnal species, while little is known about their nocturnal counterparts. Strepsirrhini is a group of nocturnal primates with galago and potto as the only representatives on mainland Africa. To assess the perception of locals and their impacts on the conservation of these primates, questionnaires were administered to 79 household heads in four villages located in community forests around Mount Cameroon National Park. Amongst the respondents, over 90% admitted that these animals are eaten in their communities. Nocturnal primates were not only hunted for food, but also used in medicine and rituals and to make drums. However, the habit of eating nocturnal primates seems to be uncommon, as most respondents had not consumed any primate bushmeat in the last 5 years. The knowledge and support of wildlife conservation manifested by the villagers did not reflect the reality on the ground, as forest clearing for agriculture takes place regularly across the villages. Our findings suggest that bushmeat is not the main threat to nocturnal primates in this area, with habitat loss potentially representing a bigger problem for their existence in the near future.


Assuntos
Strepsirhini , Animais , Biodiversidade , Camarões , Conservação dos Recursos Naturais , Mamíferos , Percepção , Primatas
9.
J Hum Evol ; 151: 102941, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33482561

RESUMO

Recent studies on hominin craniofacial evolution have focused on phenotypic integration or covariation among traits. Covariation is thought to significantly affect evolutionary trajectories, shaping the ways in which hominins and other primates could have evolved. However, the ways in which covariation itself evolves are not well understood. This study aims to investigate the role of phylogeny, development, body size, and positional behavior in shaping the strength of covariation in strepsirrhine and catarrhine primate crania (n = 1009, representing 11 genera). These factors may have been catalysts for change in the magnitude of covariation, and they have changed significantly during primate evolution and particularly hominin evolution. Modern humans in particular have slow developmental trajectories, large bodies, and a unique form of locomotion in the form of orthograde bipedalism. Variance of eigenvalues, mean integration, mean evolvability, and mean conditional evolvability was estimated and their relationship to the various factors described earlier was assessed using phylogenetic and nonphylogenetic analyses. Results indicate that some phylogenetic signal is present, but it is not equivalent across integration statistics or cranial regions. In particular, these results suggest that closely related species are more similar than more distantly related species in evolvability of the cranial base and integration of the face. Two divergent patterns were also identified, in which covariation and evolvability of the cranial base are linked to developmental rate, but those of the face are linked to body size. Neither locomotion nor posture appears related to covariation or evolvability of the primate cranium. These results suggest that overall low covariation observed in the hominin cranium may be a result of separate trends in different cranial regions.


Assuntos
Evolução Biológica , Tamanho Corporal , Catarrinos/fisiologia , Locomoção , Crânio/anatomia & histologia , Strepsirhini/fisiologia , Animais , Catarrinos/anatomia & histologia , Catarrinos/crescimento & desenvolvimento , Strepsirhini/anatomia & histologia , Strepsirhini/crescimento & desenvolvimento
10.
Zoo Biol ; 40(1): 59-64, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33135172

RESUMO

In a golden lion tamarin (Leontopithecus rosalia rosalia) colony kept indoors in a German zoo, two animals presented a sudden onset of reduced general condition, lethargy, and diarrhea. At animal capture for clinical examination, adult nematode stages were observed after stress-induced defecation. Despite treatment, two golden lion tamarins died in the following 2 days. At necropsy, spirurid stages were found in the lungs and intestine. Additionally, adult Pterygodermatites spp. were identified in histopathological samples of intestine and pancreas, confirming the previous diagnosis. Upon diagnosis, all animals were treated with ivermectin (0.2 mg/kg; SC). Thereafter, the general condition of the golden lion tamarins improved, whereby some of them excreted spirurid nematodes over 3 days. Four weeks after treatment, 20 fecal samples from the colony were examined and proved negative for parasitic stages. Given that common German cockroaches (Blattella germanica) are suitable intermediate hosts of Pterygodermatites nycticebi, 30 specimens were collected from seven different locations around the golden lion tamarins housing. Third-stage larvae of Pterygodermatites spp. were recovered from those cockroaches. Regular anthelmintic treatments, coprological screenings, and controls for intermediate hosts were recommended. More than 2 years later, P. nycticebi infection was diagnosed again histopathologically in an aye-aye (Daubentonia madagascariensis) which suddenly died. Coprological analysis confirmed the presence of spirurid eggs. Due to prosimian primates' cockroach-eating habits and given that total cockroach eradication proved impossible, continuous cockroach control strategies and regular treatments of primates are currently performed to prevent further P. nycticebi infections.


Assuntos
Leontopithecus/parasitologia , Doenças dos Macacos/parasitologia , Infecções por Rhabditida/veterinária , Strepsirhini/parasitologia , Animais , Animais de Zoológico , Antiparasitários/uso terapêutico , Blattellidae/parasitologia , Fezes/parasitologia , Feminino , Alemanha , Controle de Insetos , Ivermectina/uso terapêutico , Masculino , Doenças dos Macacos/tratamento farmacológico , Doenças dos Macacos/mortalidade , Doenças dos Macacos/prevenção & controle , Rabditídios/crescimento & desenvolvimento , Rabditídios/isolamento & purificação , Infecções por Rhabditida/tratamento farmacológico , Infecções por Rhabditida/mortalidade , Infecções por Rhabditida/prevenção & controle
11.
Anat Rec (Hoboken) ; 304(5): 1020-1053, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33015949

RESUMO

Cranial synchondroses are cartilaginous joints between basicranial bones or between basicranial bones and septal cartilage, and have been implicated as having a potential active role in determining craniofacial form. However, few studies have examined them histologically. Using histological and immunohistochemical methods, we examined all basicranial joints in serial sagittal sections of newborn heads from nine genera of primates (five anthropoids, four strepsirrhines). Each synchondrosis was examined for characteristics of active growth centers, including a zonal distribution of proliferating and hypertrophic chondrocytes, as well as corresponding changes in matrix characteristics (i.e., density and organization of Type II collagen). Results reveal three midline and three bilateral synchondroses possess attributes of active growth centers in all species (sphenooccipital, intrasphenoidal, presphenoseptal). One midline synchondrosis (ethmoseptal) and one bilateral synchondrosis (alibasisphenoidal synchondrosis [ABS]) are active growth centers in some but not all newborn primates. ABS is oriented more anteriorly in monkeys compared to lemurs and bushbabies. The sphenoethmoidal synchondrosis (SES) varies at birth: in monkeys, it is a suture-like joint (i.e., fibrous tissue between the two bones); however, in strepsirrhines, the jugum sphenoidale is ossified while the mesethmoid remains cartilaginous. No species possesses an SES that has the organization of a growth plate. Overall, our findings demonstrate that only four midline synchondroses have the potential to actively affect basicranial angularity and facial orientation during the perinatal timeframe, while the SES of anthropoids essentially transitions toward a "suture-like" function, permitting passive growth postnatally. Loss of cartilaginous continuity at SES and reorientation of ABS distinguish monkeys from strepsirrhines.


Assuntos
Cartilagem/crescimento & desenvolvimento , Suturas Cranianas/crescimento & desenvolvimento , Crânio/crescimento & desenvolvimento , Strepsirhini/crescimento & desenvolvimento , Animais , Animais Recém-Nascidos , Osteogênese/fisiologia
12.
Elife ; 92020 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-33205751

RESUMO

Sex chromosomes are typically comprised of a non-recombining region and a recombining pseudoautosomal region. Accurately quantifying the relative size of these regions is critical for sex-chromosome biology both from a functional and evolutionary perspective. The evolution of the pseudoautosomal boundary (PAB) is well documented in haplorrhines (apes and monkeys) but not in strepsirrhines (lemurs and lorises). Here, we studied the PAB of seven species representing the main strepsirrhine lineages by sequencing a male and a female genome in each species and using sex differences in coverage to identify the PAB. We found that during primate evolution, the PAB has remained unchanged in strepsirrhines whereas several recombination suppression events moved the PAB and shortened the pseudoautosomal region in haplorrhines. Strepsirrhines are well known to have much lower sexual dimorphism than haplorrhines. We suggest that mutations with antagonistic effects between males and females have driven recombination suppression and PAB evolution in haplorrhines.


Assuntos
Evolução Molecular , Strepsirhini/genética , Animais , Feminino , Masculino , Polimorfismo de Nucleotídeo Único , Cromossomos Sexuais , Especificidade da Espécie
13.
Folia Primatol (Basel) ; 91(6): 558-574, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32663822

RESUMO

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.


Assuntos
Ecossistema , Comportamento de Retorno ao Território Vital , Strepsirhini , Animais , Comportamento Apetitivo , Comportamento Animal , Feminino , Sistemas de Informação Geográfica , Invertebrados , Locomoção , Madagáscar , Masculino , Comportamento de Nidação , Estações do Ano
14.
Am J Phys Anthropol ; 173(2): 307-321, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32666552

RESUMO

OBJECTIVES: Phylogenies consistently group the folivorous Lepilemur species with the small-bodied insectivorous-frugivorous cheirogaleids. Juvenile lepilemurs and adult cheirogaleids share allometries in most aspects of skull morphology, except the palate. We investigated potential influences on palate shape in these taxa and several outgroups using geometric morphometrics. MATERIALS AND METHODS: Our sample included representatives of four extant strepsirrhine families, Cheirogaleidae (including Lepilemurinae), Lemuridae, Indriidae, and Galagidae, and one subfossil Megaladapis. Our dataset comprised 32 landmarks collected from 397 specimens representing 15 genera and 28 species, and was analyzed using generalized procrustes analyses and between group principal component analysis. We explored the influence of size, phylogeny, diet, and the propagation of loud vocalizations on palate shape. RESULTS: While congeneric species clustered within the morphospace, the phylomorphospace did not mirror molecular phylogenetic hypotheses of higher-order relationships. Four palate forms were distinguished within the Cheirogaleidae. Diet, strongly linked to body size, had the single greatest influence on palate shape. The production of long-distance advertisement calls was most often associated with positive scores on the PC1 axis. DISCUSSION: Our results suggest that the extensive variation in palate shape among Cheirogaleidae is related to dietary shifts that accompanied changes in body size during the clade's radiation. Molecular phylogenies indicate that cheirogaleid diversification involved repeated dwarfing events, which in turn drove dietary shifts from ancestral folivory-frugivory to frugivory, gummivory, and faunivory in the descendant species. The elongated Lepilemur palate is probably related to accelerated eruption of the cheek teeth to render juveniles competent to shear leaves upon weaning.


Assuntos
Comportamento Alimentar/fisiologia , Palato/anatomia & histologia , Strepsirhini/anatomia & histologia , Strepsirhini/classificação , Animais , Antropologia Física , Antropometria , Evolução Biológica , Tamanho Corporal/fisiologia , Cheirogaleidae/anatomia & histologia , Cheirogaleidae/classificação , Dieta , Feminino , Fósseis , Masculino , Filogenia
15.
Bioinspir Biomim ; 15(5): 056003, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32485699

RESUMO

The aye-aye (Daubentonia madagascariensis) is best known for its unique acoustic-based foraging behavior called 'tap-scanning' or 'percussive foraging'. The tap-scanning is a unique behavior allowing aye-aye to locate small cavities beneath tree bark and extract wood-boring larvae from it. The tap-scanning requires the animal auditory system to have exceptional acoustic near-field sensitivity. This paper has experimentally investigated the effects of external pinna in the acoustic sensing and detection capabilities of aye-ayes. To experimentally evaluate the effects of external ear (pinna) of the aye-aye, the tap-scanning process was simulated using a robotic arm. A pinna was 3D printed using a CT scan obtained from a carcass. The pinna's effect on the acoustic near-field has been evaluated in time and frequency domains for simulated tap-scanning with the pinna in upright and cupped positions. This idea originates from behavioral observations of the aye-aye using its ears in this way. The results suggest that the aye-aye can substantially enhance its acoustic near-field sensitivity through a cupped conformation during tap-scanning. Three phenomena contribute to this substantial enhancement of the acoustic near-field: (i) a considerable increase in the signal-to-noise ratio, (ii) the creation of a focal area and potentially a focal point to increase the spatial resolution, and (iii) an increase in the receiver peak frequency by changing near-field beam pattern for higher frequencies that can result in greater sensitivity due to a smaller wavelength.


Assuntos
Acústica , Biomimética , Robótica , Strepsirhini/fisiologia , Animais , Comportamento Animal , Comportamento Alimentar , Larva
16.
Philos Trans R Soc Lond B Biol Sci ; 375(1800): 20190264, 2020 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-32306880

RESUMO

The study of human chemical communication benefits from comparative perspectives that relate humans, conceptually and empirically, to other primates. All major primate groups rely on intraspecific chemosignals, but strepsirrhines present the greatest diversity and specialization, providing a rich framework for examining design, delivery and perception. Strepsirrhines actively scent mark, possess a functional vomeronasal organ, investigate scents via olfactory and gustatory means, and are exquisitely sensitive to chemically encoded messages. Variation in delivery, scent mixing and multimodality alters signal detection, longevity and intended audience. Based on an integrative, 19-species review, the main scent source used (excretory versus glandular) differentiates nocturnal from diurnal or cathemeral species, reflecting differing socioecological demands and evolutionary trajectories. Condition-dependent signals reflect immutable (species, sex, identity, genetic diversity, immunity and kinship) and transient (health, social status, reproductive state and breeding history) traits, consistent with socio-reproductive functions. Sex reversals in glandular elaboration, marking rates or chemical richness in female-dominant species implicate sexual selection of olfactory ornaments in both sexes. Whereas some compounds may be endogenously produced and modified (e.g. via hormones), microbial analyses of different odorants support the fermentation hypothesis of bacterial contribution. The intimate contexts of information transfer and varied functions provide important parallels applicable to olfactory communication in humans. This article is part of the Theo Murphy meeting issue 'Olfactory communication in humans'.


Assuntos
Comunicação Animal , Evolução Biológica , Odorantes , Percepção Olfatória , Olfato , Strepsirhini/fisiologia , Animais , Humanos , Strepsirhini/psicologia
17.
J Hum Evol ; 139: 102708, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31972428

RESUMO

We describe the first known navicular bones for an Eocene euprimate from Europe and assess their implications for early patterns of locomotor evolution in primates. Recovered from the fossil site of Sant Jaume de Frontanyà-3C (Barcelona, Spain), the naviculars are attributed to Anchomomys frontanyensis. The small size of A. frontanyensis allows us to consider behavioral implications of comparisons with omomyiforms, regardless of allometric sources of navicular variation. Researchers usually consider omomyiforms to be more prone to leaping than contemporaneous adapiforms partly because of the more pronounced elongation of omomyiform tarsal elements. However, A. frontanyensis differs from other adapiforms and is similar to some omomyiforms in its more elongated navicular proportions. Although this might raise questions about attribution of these naviculars to A. frontanyensis, the elements exhibit clear strepsirrhine affinities leaving little doubt about the attribution: the bones' mesocuneiform facets contact their cuboid facets. We further propose that this strepsirrhine-specific feature in A. frontanyensis and other adapiforms reflects use of more inverted foot postures and potentially smaller substrates than sympatric omomyiforms that lack it. Thus substrate differences may have influenced niche partitioning in Eocene euprimate communities along with differences in locomotor agility. As previous studies on the astragalus and the calcaneus have suggested, this study on the navicular is consistent with the hypothesis that the locomotor mode of A. frontanyensis was similar to that of extant cheirogaleids, especially species of Microcebus and Mirza.


Assuntos
Fósseis/anatomia & histologia , Locomoção , Strepsirhini/anatomia & histologia , Ossos do Tarso/anatomia & histologia , Animais , Evolução Biológica , Espanha , Strepsirhini/fisiologia
18.
Folia Primatol (Basel) ; 91(1): 69-82, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31085921

RESUMO

Primates face many climate and land use change threats, making long-term population monitoring critical to prioritizing conservation efforts. Ground-based line transects are typically conducted to estimate and monitor primate populations. However, transects may be costly and logistically challenging. We sought to test whether low-cost (<5,000 USD), ready-to-use unmanned aerial vehicles (UAVs) could effectively monitor primate populations in north-eastern Madagascar. Critically Endangered [A3cd] golden-crowned sifakas (Propithecus tattersalli) are medium-sized, white lemurs whose creamy colour contrasts against defoliated tree canopies, making them an ideal study species for aerial counts. Quad-copter UAV flights over sifaka groups did not elicit antipredator responses. Photographs demonstrated the ability of UAVs to capture viable imagery of sifakas from approximately 20 m above ground level. Unfortunately, crashes resulting from an inability to programme automated flights over hilly forests cut this pilot study short, highlighting several challenges that remain to implementing UAVs in remote field studies. This study demonstrates that while UAVs offer considerable promise in the future of primate research and conservation, high start-up costs and remote field conditions provide challenging obstacles to first time users hoping to use this exciting new technology. Furthermore, we strongly recommend that thermal cameras be used for direct primate counts with UAVs.


Assuntos
Aeronaves/instrumentação , Strepsirhini , Zoologia/métodos , Animais , Madagáscar , Projetos Piloto , Vigilância da População/métodos
19.
Folia Primatol (Basel) ; 91(1): 48-68, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31390626

RESUMO

Female dominance is often associated with lemurs. However, consensus does not exist among primatologists on how to define, measure, or explain female dominance. This review explores the utility of applying a broader concept of power to understanding lemur intersexual relationships. In this framework, power is defined as arising from an asymmetry in a dyadic relationship and can be divided into 2 types: dominance and leverage. Intersexual asymmetries based upon females having superior fighting ability are considered female dominance. However, economic power also exists, and females with resource-based power exhibit female leverage. Additionally, power has 4 characteristics (base, means, amount, and scope) that describe the precise nature of observed phenomena. This article utilizes the 4 characteristics outlined in the power framework to review the existing "female dominance" literature for lemurs and highlights the value of adopting both an expanded concept of power and a more precise language. By placing the multiple phenomena currently labeled under the single term "female dominance" within the power framework, much of the confusion disappears. Thus, not only is the debate reframed, facilitating endeavors to find evolutionary explanations, but the uniqueness of female power in lemurs can be determined empirically rather than by definition.


Assuntos
Predomínio Social , Strepsirhini/psicologia , Animais , Evolução Biológica , Feminino , Fatores Sexuais , Strepsirhini/fisiologia
20.
Anat Rec (Hoboken) ; 303(2): 282-294, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31714689

RESUMO

Relative to all other primates, the aye-aye (Daubentonia madagascariensis) exists at the extremes of both morphology and behavior. Its specialized anatomy-which includes hypselodont incisors and highly derived manual digits-reflects a dietary niche, unique among primates, which combines tap-foraging with gouging to locate and extract wood-boring larvae. Here, we explore the impact of this extreme dietary ecology upon the masticatory musculature of this taxon with reference to a second, similarly sized but highly generalist lemuriform-the mongoose lemur (Eulemur mongoz). Using non-destructive, high-resolution diffusible iodine-based contrast-enhanced computed tomography techniques, we reconstruct the three-dimensional volumes of eight masticatory muscles, and, for the first time in strepsirrhines, isolate and visualize their constituent muscle fascicles in situ and in three dimensions. Using these data, we report muscle volumes, forces, and fascicle lengths from each muscle portion, as well as their orientation relative to two standardized anatomical planes. Our findings demonstrate the overbuilt nature of the aye-aye's masticatory apparatus, in which each muscle possesses an absolutely and relatively larger muscle volume and PCSA than its counterpart in the mongoose lemur. Likewise, for several adductor muscles, aye-ayes also possess relatively greater fascicle lengths. Finally, we note several unusual features within the lateral pterygoid of the aye-aye-the muscle most responsible for jaw protrusion-that relate to force maximization and reorientation. As this jaw motion is critical to gouging, we interpret these differences to reflect highly specific specializations that facilitate the aye-aye's extreme subsistence strategy. Anat Rec, 2019. © 2019 American Association for Anatomy Anat Rec, 303:282-294, 2020. © 2019 American Association for Anatomy.


Assuntos
Adaptação Fisiológica/fisiologia , Músculos da Mastigação/anatomia & histologia , Strepsirhini/anatomia & histologia , Dente/anatomia & histologia , Animais , Comportamento Alimentar/fisiologia , Masculino , Músculos da Mastigação/diagnóstico por imagem , Músculos da Mastigação/fisiologia , Strepsirhini/fisiologia , Dente/diagnóstico por imagem , Microtomografia por Raio-X
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