| perception of facial expressions reveals selective affect-biased attention in humans and orangutans. | rapid detection and recognition of another individual's emotional state plays a pivotal role for humans and, most likely, other social species. proper reactions contribute to an individual's survival in potentially dangerous situations; this is ensured by a preferential attention towards salient cues. the predisposition to attend to certain categories of affectively salient stimuli- also referred to as affect-biased attention - is likely shared with other species, since fast detection of and app ... | 2017 | 28798378 |
| cyclical nursing patterns in wild orangutans. | nursing behavior is notoriously difficult to study in arboreal primates, particularly when offspring suckle inconspicuously in nests. orangutans have the most prolonged nursing period of any mammal, with the cessation of suckling (weaning) estimated to occur at 6 to 8 years of age in the wild. milk consumption is hypothesized to be relatively constant over this period, but direct evidence is limited. we previously demonstrated that trace element analysis of bioavailable elements from milk, such ... | 2017 | 28560319 |
| orangutan trade, confiscations, and lack of prosecutions in indonesia. | prosecuting and sentencing law breakers punishes the offender and acts as a deterrent for future law breakers. with thousands of sumatran and bornean orangutans (pongo abelii and p. pygmaeus) having entered private and government rescue centers and facilities, i evaluate the role of successful prosecution in orangutan conservation in indonesia. orangutans have been protected in indonesian since 1931 and they are not allowed to be traded or to be kept as pets. in the period 1993-2016 at least 440 ... | 2017 | 28407279 |
| two orangutan species have evolved different kir alleles and haplotypes. | the immune and reproductive functions of human nk cells are regulated by interactions of the c1 and c2 epitopes of hla-c with c1-specific and c2-specific lineage iii killer cell ig-like receptors (kir). this rapidly evolving and diverse system of ligands and receptors is restricted to humans and great apes. in this context, the orangutan has particular relevance because it represents an evolutionary intermediate, one having the c1 epitope and corresponding kir but lacking the c2 epitope. through ... | 2017 | 28264973 |
| time does not help orangutans pongo abelii solve physical problems. | many questions in animal intelligence and cognition research are challenging. one challenge is to identify mechanisms underlying reasoning in experiments. here, we provide a way to design such tests in non-human animals. we know from research in skill acquisition in humans that reasoning and thinking can take time because some problems are processed in multiple steps before a solution is reached (e.g., during mental arithmetics). if animals are able to learn through similar processes their decis ... | 2017 | 28223959 |
| evidence that the rate of strong selective sweeps increases with population size in the great apes. | quantifying the number of selective sweeps and their combined effects on genomic diversity in humans and other great apes is notoriously difficult. here we address the question using a comparative approach to contrast diversity patterns according to the distance from genes in all great ape taxa. the extent of diversity reduction near genes compared with the rest of intergenic sequences is greater in a species with larger effective population size. also, the maximum distance from genes at which t ... | 2017 | 28137852 |
| orientation toward humans predicts cognitive performance in orang-utans. | non-human animals sometimes show marked intraspecific variation in their cognitive abilities that may reflect variation in external inputs and experience during the developmental period. we examined variation in exploration and cognitive performance on a problem-solving task in a large sample of captive orang-utans (pongo abelii &p. pygmaeus, nā=ā103) that had experienced different rearing and housing conditions during ontogeny, including human exposure. in addition to measuring exploration and ... | 2017 | 28067260 |
| orangutans (pongo abelii) seek information about tool functionality in a metacognition tubes task. | nonhuman primates appear to engage in metacognition by knowing when they need to search for relevant information for solving the tubes task. the task involves presenting subjects with a number of tubes with only 1 having food hidden inside. before choosing, subjects look inside the tubes more often when they do not know which 1 contains the food (hidden trials) compared to when they do know this information (visible trials). it is argued, however, that nonmetacognitive general food searching str ... | 2016 | 27841455 |
| development of foraging skills in two orangutan populations: needing to learn or needing to grow? | orangutans have one of the slowest-paced life histories of all mammals. whereas life-history theory suggests that the time to reach adulthood is constrained by the time needed to reach adult body size, the needing-to-learn hypothesis instead suggests that it is limited by the time needed to acquire adult-level skills. to test between these two hypotheses, we compared the development of foraging skills and growth trajectories of immature wild orangutans in two populations: at tuanan (pongo pygmae ... | 2016 | 27708679 |
| social manipulation in nonhuman primates: cognitive and motivational determinants. | social interactions are the result of individuals' cooperative and competitive tendencies expressed over an extended period of time. although social manipulation, i.e., using another individual to achieve one's own goals, is a crucial aspect of social interactions, there has been no comprehensive attempt to differentiate its various types and to map its cognitive and motivational determinants. for this purpose, we survey in this article the experimental literature on social interactions in nonhu ... | 2016 | 27639446 |
| affective forecasting in an orangutan: predicting the hedonic outcome of novel juice mixes. | affective forecasting is an ability that allows the prediction of the hedonic outcome of never-before experienced situations, by mentally recombining elements of prior experiences into possible scenarios, and pre-experiencing what these might feel like. it has been hypothesised that this ability is uniquely human. for example, given prior experience with the ingredients, but in the absence of direct experience with the mixture, only humans are said to be able to predict that lemonade tastes bett ... | 2016 | 27515937 |
| cognitive differences between orang-utan species: a test of the cultural intelligence hypothesis. | cultural species can - or even prefer to - learn their skills from conspecifics. according to the cultural intelligence hypothesis, selection on underlying mechanisms not only improves this social learning ability but also the asocial (individual) learning ability. thus, species with systematically richer opportunities to socially acquire knowledge and skills should over time evolve to become more intelligent. we experimentally compared the problem-solving ability of sumatran orang-utans (pongo ... | 2016 | 27466052 |
| differences in the visual perception of symmetric patterns in orangutans (pongo pygmaeus abelii) and two human cultural groups: a comparative eye-tracking study. | symmetric structures are of importance in relation to aesthetic preference. to investigate whether the preference for symmetric patterns is unique to humans, independent of their cultural background, we compared two human populations with distinct cultural backgrounds (namibian hunter-gatherers and german town dwellers) with one species of non-human great apes (orangutans) in their viewing behavior regarding symmetric and asymmetric patterns in two levels of complexity. in addition, the human pa ... | 2016 | 27065184 |
| sinusitis, bronchiectasis, and flatus in a sumatran orangutan (pongo abelii): could this be cystic fibrosis? | a 31-yr-old male sumatran orangutan (pongo abelii) presented with 14 yr of chronic purulent nasal drainage and cough with intermittent exacerbation of symptoms requiring systemic antibiotic treatment. he was diagnosed with a cystic fibrosis (cf)-like condition. evaluation consisted of bronchoscopy with bronchoalveolar lavage, culture, and computed tomography scanning of the sinuses and chest. although the presence of low fecal elastase activity increased the suspicion for a diagnosis of cf, pilo ... | 2016 | 27010300 |
| land-cover changes predict steep declines for the sumatran orangutan (pongo abelii). | positive news about sumatran orangutans is rare. the species is critically endangered because of forest loss and poaching, and therefore, determining the impact of future land-use change on this species is important. to date, the total sumatran orangutan population has been estimated at 6600 individuals. on the basis of new transect surveys, we estimate a population of 14,613 in 2015. this higher estimate is due to three factors. first, orangutans were found at higher elevations, elevations prev ... | 2016 | 26973868 |
| complex mhc class i gene transcription profiles and their functional impact in orangutans. | mhc haplotypes of humans and the african great ape species have one copy of the mhc-a, -b, and -c genes. in contrast, mhc haplotypes of orangutans, the asian great ape species, exhibit variation in the number of gene copies. an in-depth analysis of the mhc class i gene repertoire in the two orangutan species, pongo abelii and pongo pygmaeus, is presented in this article. this analysis involved sanger and next-generation sequencing methodologies, revealing diverse and complicated transcription pr ... | 2016 | 26685209 |
| community motivations to engage in conservation behavior to conserve the sumatran orangutan. | community-based conservation programs in developing countries are often based on the assumption that heteronomous motivation (e.g., extrinsic incentives such as economic rewards and pressure or coercion to act) will incite local communities to adopt conservation behaviors. however, this may not be as effective or sustainable as autonomous motivations (e.g., an intrinsic desire to act due to inherent enjoyment or self-identification with a behavior and through freedom of choice). we analyzed the ... | 2016 | 26511405 |
| derivation of induced pluripotent stem cells from orangutan skin fibroblasts. | orangutans are an endangered species whose natural habitats are restricted to the southeast asian islands of borneo and sumatra. along with the african great apes, orangutans are among the closest living relatives to humans. for potential species conservation and functional genomics studies, we derived induced pluripotent stem cells (ipscs) from cryopreserved somatic cells obtained from captive orangutans. | 2015 | 26475477 |
| sumatran orangutans and the world war ii. | | 2015 | 26050555 |
| orangutans (pongo spp.) do not spontaneously share benefits with familiar conspecifics in a choice paradigm. | humans are thought to be unique in their ability to help others voluntarily even though it may sometimes incur substantial costs. however, there are a growing number of studies showing that prosocial behaviors can be observed, not only in humans, but also among nonhuman primates that live in complex social groups. prosociality has often been described as a major factor that facilitates group living. nonetheless, it has seldom been explored whether solitary living primates, such as orangutans, sh ... | 2015 | 25739582 |
| reconstructing the demographic history of orang-utans using approximate bayesian computation. | investigating how different evolutionary forces have shaped patterns of dna variation within and among species requires detailed knowledge of their demographic history. orang-utans, whose distribution is currently restricted to the south-east asian islands of borneo (pongo pygmaeus) and sumatra (pongo abelii), have likely experienced a complex demographic history, influenced by recurrent changes in climate and sea levels, volcanic activities and anthropogenic pressures. using the most extensive ... | 2015 | 25439562 |
| food mechanical properties, feeding ecology, and the mandibular morphology of wild orangutans. | bornean orangutan mandibular morphology has been functionally linked to the exploitation of hard and tough foods, based on evidence that pongo pygmaeus wurmbii spends a greater percentage of time feeding on bark, seeds and vegetation compared with pongo abelii (sumatran orangutans) and the assumption that these tissues are more challenging to process than fruit pulp. we measured and compared toughness (r) and young's modulus (e) of ripe and unripe foods exploited by p. abelii and p. p. wurmbii. ... | 2014 | 25038032 |
| conservation strategies for orangutans: reintroduction versus habitat preservation and the benefits of sustainably logged forest. | the sumatran orangutan is currently listed by the iucn as critically endangered and the bornean species as endangered. unless effective conservation measures are enacted quickly, most orangutan populations without adequate protection face a dire future. two main strategies are being pursued to conserve orangutans: (i) rehabilitation and reintroduction of ex-captive or displaced individuals; and (ii) protection of their forest habitat to abate threats like deforestation and hunting. these strateg ... | 2014 | 25025134 |
| reintroduced sumatran orangutans (pongo abelii): using major food tree species as indicators of habitat suitability. | reintroducing orangutans (pongo spp.) into the wild requires a suitable, secure habitat. to identify acceptable areas for their reintroduction and define priority conservation sites, we analysed the tree species composition in the bukit tigapuluh ecosystem in jambi, sumatra. we used this information to determine the distribution patterns of those species that represent an essential part of the diet of reintroduced orangutans. important orangutan food tree species showed significant differences i ... | 2014 | 24504132 |
| variation in perikymata counts between repetitive episodes of linear enamel hypoplasia among orangutans from sumatra and borneo. | the goal of this study is to evaluate whether repetitive linear enamel hypoplasia (rleh) in apes is ecologically informative. leh, which appears as grooves of thinner enamel often caused by malnutrition and/or disease, is a permanent record of departures from developmental homeostasis in infant and juvenile apes. orangutans were selected for the study as they are a threatened species, have a remarkably high prevalence of rleh, and because sumatra is deemed a better habitat for orangutans than is ... | 2014 | 24500972 |
| quantification of the dental morphology of orangutans. | orangutans are believed to have close biological affinities to humans. teeth being the hardest tissue provide useful information on primate evolution. furthermore, knowledge of the pulp chamber and root canal morphology is important for dental treatment. a female bornean orangutan and a sumatran male orangutan skull were available for this study. both of their dentitions, comprising 50 teeth, were scanned employing the cone-beam computed tomography for both metrical and nonmetrical analyses. mea ... | 2013 | 24348143 |
| population genomic analysis reveals a rich speciation and demographic history of orang-utans (pongo pygmaeus and pongo abelii). | to gain insights into evolutionary forces that have shaped the history of bornean and sumatran populations of orang-utans, we compare patterns of variation across more than 11 million single nucleotide polymorphisms found by previous mitochondrial and autosomal genome sequencing of 10 wild-caught orang-utans. our analysis of the mitochondrial data yields a far more ancient split time between the two populations (~3.4 million years ago) than estimates based on autosomal data (0.4 million years ag ... | 2013 | 24194868 |
| can orangutans (pongo abelii) infer tool functionality? | it is debatable whether apes can reason about the unobservable properties of tools. we tested orangutans for this ability with a range of tool tasks that they could solve by using observational cues to infer tool functionality. in experiment 1, subjects successfully chose an unbroken tool over a broken one when each tool's middle section was hidden. this prevented seeing which tool was functional but it could be inferred by noting the tools' visible ends that were either disjointed (broken tool) ... | 2014 | 24132413 |
| wild orangutan males plan and communicate their travel direction one day in advance. | the ability to plan for the future beyond immediate needs would be adaptive to many animal species, but is widely thought to be uniquely human. although studies in captivity have shown that great apes are capable of planning for future needs, it is unknown whether and how they use this ability in the wild. flanged male sumatran orangutans (pongo abelii) emit long calls, which females use to maintain earshot associations with them. we tested whether long calls serve to communicate a male's ever-c ... | 2013 | 24040357 |
| quantity matching by an orangutan (pongo abelii). | an adult male orangutan (pongo abelii) was presented with a series of delayed matching-to-sample (dmts) tasks in which he was to match images based on (a) the number of individual animals depicted in the photograph (from 1 to 4), (b) the number of abstract shapes presented in the stimulus (from 1 to 4), or (c) the number of dots presented in the stimulus (from 1 to 4, 4-7, or 7-10). the spatial arrangement of the dots and the background color of the stimuli varied, and the size of the dots was m ... | 2014 | 23873480 |
| factors affecting the compliance and sway properties of tree branches used by the sumatran orangutan (pongo abelii). | the tropical arboreal environment is a mechanically complex and varied habitat. arboreal inhabitants must adapt to changes in the compliance and stability of supports when moving around trees. because the orangutan is the largest habitual arboreal inhabitant, it is unusually susceptible to branch compliance and stability and therefore represents a unique animal model to help investigate how animals cope with the mechanical heterogeneity of the tropical canopy. the aim of this study was to invest ... | 2013 | 23844116 |
| uncovering the cultural knowledge of sanctuary apes. | behavioral differences observed between wild communities of the same species have been called "cultures" by some researchers who aimed to underline the similarities with human cultures. however, whether these differences truly result from social learning processes is debated. despite promising recent research, data acquired in the wild still fail to exclude genetic and ecological factors from being potential explanations for the observed behavioral differences. a potential way to address this pr ... | 2013 | 23713136 |
| variation in developmental arrest among male orangutans: a comparison between a sumatran and a bornean population. | the presence of two sexually active male morphs with different reproductive tactics in a single species is rare among mammals. the most striking case of bimaturism among primates is exhibited by the orangutan (pongo spp), in which one adult morph, the unflanged male, irreversibly develops into another one, the flanged form, but may remain arrested in the unflanged state for many years. however, it has been suggested that such arrest is less common among bornean orangutans (pongo pygmaeus) compar ... | 2013 | 23510027 |
| sumatran orangutans differ in their cultural knowledge but not in their cognitive abilities. | animal cultures are controversial because the method used to isolate culture in animals aims at excluding genetic and environmental influences rather than demonstrating social learning. here, we analyzed these factors in parallel in captivity to determine their influences on tool use. we exposed sumatran orangutan (pongo abelii) orphans from tool-using and non-tool-using regions (western swamps and eastern langkat, respectively) that differed in both genetic and cultural backgrounds to a raking ... | 2012 | 23142043 |
| feature versus spatial strategies by orangutans (pongo abelii) and human children (homo sapiens) in a cross-dimensional task. | despite the fact that photographic stimuli are used across experimental contexts with both human and nonhuman subjects, the nature of individuals' perceptions of these stimuli is still not well understood. in the present experiments, we tested whether three orangutans and 36 human children could use photographic information presented on a computer screen to solve a perceptually corresponding problem in the physical domain. furthermore, we tested the cues that aided in this process by pitting fea ... | 2013 | 23106800 |
| marked population structure and recent migration in the critically endangered sumatran orangutan (pongo abelii). | a multitude of factors influence how natural populations are genetically structured, including dispersal barriers, inhomogeneous habitats, and social organization. such population subdivision is of special concern in endangered species, as it may lead to reduced adaptive potential and inbreeding in local subpopulations, thus increasing the risk of future extinctions. with only 6600 animals left in the wild, sumatran orangutans (pongo abelii) are among the most endangered, but also most enigmatic ... | 2012 | 23077232 |
| forest structure and support availability influence orangutan locomotion in sumatra and borneo. | the influence of habitat structure and support availability on support use is an important aspect of understanding locomotor behavior in arboreal primates. we compared habitat structure and support availability in three orangutan study sites-two on sumatra (pongo abelii) in the dry-lowland forest of ketambe and peat swamp forest of suaq balimbing, and one on borneo (pongo pygmaeus wurmbii) in the disturbed peat swamp forest of sabangau-to better understand orangutan habitat use. our analysis rev ... | 2012 | 22915011 |
| orangutans (pongo pygmaeus and pongo abelii) understand connectivity in the skewered grape tool task. | great apes appear to have limited knowledge of tool functionality when they are presented with tasks that involve a physical connection between a tool and a reward. for instance, they fail to understand that pulling a rope with a reward tied to its end is more beneficial than pulling a rope that only touches a reward. apes show more success when both ropes have rewards tied to their ends but one rope is nonfunctional because it is clearly separated into aligned sections. it is unclear, however, ... | 2013 | 22686164 |
| a model for the evolution of developmental arrest in male orangutans. | male sumatran orangutans (pongo abelii) may delay for many years the acquisition of the full array of secondary sexual traits, including their characteristic cheek flanges. such flexible developmental arrest is unique among male primates. among male bornean orangutans (pongo pygmaeus) such long delays appear less common. here, we develop a simple model to identify the conditions under which developmental arrest can be adaptive. we show that the baseline strategy (i.e., males are not susceptible ... | 2012 | 22552966 |
| molecular diversity of methanogens in fecal samples from captive sumatran orangutans (pongo abelii). | methane emissions have been previously detected from orangutans, but characterization of the diversity of methanogens in this species has yet to be completed. this preliminary study identified methanogen producing microorganims, also called methanogens, present in the feces from a colony of captive sumatran orangutans at the perth zoo. all animals were housed in the same enclosure and were fed primarily a frugivorous diet. methanogens were detected using a 16s rrna gene clone library. a total of ... | 2012 | 22511523 |
| an inversion of chromosome 2 that distinguishes between bornean and sumatran orangutans. | | 1979 | 761478 |
| colonic diverticulosis and diverticular hemorrhage in a geriatric female orangutan ( pongo abelii). | a 57-yr-old female sumatran orangutan ( pongo abelii) presented with signs of intermittent lethargy and inappetence, then subsequently developed profuse hemorrhagic diarrhea. colonoscopy under anesthesia revealed diverticulosis of the descending colon, with multiple large diverticula containing fecoliths. there was no evidence of diverticulitis, but a regenerative anemia had developed following an acute diverticular bleed. the orangutan recovered with conservative therapy. colonic diverticulosis ... | 2017 | 29297793 |
| foxp2 variation in great ape populations offers insight into the evolution of communication skills. | the gene coding for the forkhead box protein p2 (foxp2) is associated with human language disorders. evolutionary changes in this gene are hypothesized to have contributed to the emergence of speech and language in the human lineage. although foxp2 is highly conserved across most mammals, humans differ at two functional amino acid substitutions from chimpanzees, bonobos and gorillas, with an additional fixed substitution found in orangutans. however, foxp2 has been characterized in only a small ... | 2017 | 29203828 |
| grouping behavior of sumatran orangutans (pongo abelii) and tapanuli orangutans (pongo tapanuliensis) living in forest with low fruit abundance. | in contrast to the african great apes, orangutans (pongo spp.) are semisolitary: individuals are often on their own, but form aggregations more often than expected by chance. these temporary aggregations provide social benefits such as mating opportunities. when fruit availability is high, costs of aggregating should be lower, because competition is less pronounced. therefore, average party size is expected to be higher when fruit availability is high. this hypothesis would also explain why oran ... | 2020 | 32187394 |
| morphometric, behavioral, and genomic evidence for a new orangutan species. | six extant species of non-human great apes are currently recognized: sumatran and bornean orangutans, eastern and western gorillas, and chimpanzees and bonobos [1]. however, large gaps remain in our knowledge of fine-scale variation in hominoid morphology, behavior, and genetics, and aspects of great ape taxonomy remain in flux. this is particularly true for orangutans (genus: pongo), the only asian great apes and phylogenetically our most distant relatives among extant hominids [1]. designation ... | 2017 | 29103940 |
| a pilot study for estimating the cardiopulmonary signals of diverse exotic animals using a digital camera. | monitoring the cardiopulmonary signal of animals is a challenge for veterinarians in conditions when contact with a conscious animal is inconvenient, difficult, damaging, distressing or dangerous to personnel or the animal subject. in this pilot study, we demonstrate a computer vision-based system and use examples of exotic, untamed species to demonstrate this means to extract the cardiopulmonary signal. subject animals included the following species: giant panda (ailuropoda melanoleuca), africa ... | 2019 | 31835550 |
| diversity and temporal dynamics of primate milk microbiomes. | milk is inhabited by a community of bacteria and is one of the first postnatal sources of microbial exposure for mammalian young. bacteria in breast milk may enhance immune development, improve intestinal health, and stimulate the gut-brain axis for infants. variation in milk microbiome structure (e.g., operational taxonomic unit [otu] diversity, community composition) may lead to different infant developmental outcomes. milk microbiome structure may depend on evolutionary processes acting at th ... | 2019 | 31219214 |
| monkeys (sapajus apella and macaca tonkeana) and great apes (gorilla gorilla, pongo abelii, pan paniscus, and pan troglodytes) play for the highest bid. | many studies investigate the decisions made by animals by focusing on their attitudes toward risk, that is, risk-seeking, risk neutrality, or risk aversion. however, little attention has been paid to the extent to which individuals understand the different odds of outcomes. in a previous gambling task involving 18 different lotteries (pelé, broihanne, thierry, call, & dufour, 2014), nonhuman primates used probabilities of gains and losses to make their decision. although the use of complex mathe ... | 2019 | 30589294 |
| high order formation and evolution of hornerin in primates. | genomic duplication or loss can accelerate evolution because the number of repeats could affect molecular pathways and phenotypes. we have previously reported that the repeated region of filaggrin (flg), a crucial component of the outer layers of mammalian skin, had high levels of nucleotide diversity with species-specific divergence and expansion and that it evolved under the birth-and-death model. we focused on hornerin (hrnr), a member of the same gene family that harbor similar tandem repeat ... | 2018 | 30256937 |
| nomenclature for the kir of non-human species. | the increasing number of killer immunoglobulin-like receptor (kir) sequences available for non-human primate species and cattle has prompted development of a centralized database, guidelines for a standardized nomenclature, and minimum requirements for database submission. the guidelines and nomenclature are based on those used for human kir and incorporate modifications made for inclusion of non-human species in the companion ipd-nhkir database. included in this first release are the rhesus mac ... | 2018 | 29869002 |
| serological diagnosis of baylisascaris procyonis in primates using a human elisa test. | the usefulness of a human enzyme-linked immunosorbent assay (elisa) for serological diagnosis of baylisascaris procyonis larva migrans was assessed in nonhuman primates (nhp). the test was originally developed as an assay performed on human samples at purdue university. six participating zoos submitted 258 nhp serum samples, spanning these major phylogenetic groups: 1) great apes (n = 84), 2) lesser apes (n = 17), 3) old world monkeys (n = 84), 4) new world monkeys (n = 20), and 5) prosimians (n ... | 2019 | 31260208 |
| hand preferences in captive gorillas, orang-utans and gibbons. | hand preference was assessed in 12 gorillas (gorilla gorilla gorilla), 13 orang-utans (pongo pygmaeus abelii), and 9 gibbons (hylobates lar) by using a floor retrieval task and a mesh retrieval task. hand preference was also assessed in 8 gorillas and 8 orang-utans by using a task involving the unfastening of a hasp. a bipedal requirement during testing (mesh retrieval task) facilitated detection of hand preferences. a significant left-hand preference was found for the gibbons with 6 of 6 gibbon ... | 1990 | 31963993 |
| prior experience mediates the usage of food items as tools in great apes (pan paniscus, pan troglodytes, gorilla gorilla, and pongo abelii). | humans use tools with specific functions to solve tasks more efficiently. however, functional specialization often comes at a cost: it can hinder the production of actions that are not usually performed with those tools, thus resulting in a fixation effect (functional fixedness). little is known about whether our closest living relatives, the nonhuman great apes, are vulnerable to this detrimental effect of experience. we examined whether great apes from 4 species (n = 35) would become fixated o ... | 2020 | 32463250 |
| mandibular corpus shape is a taxonomic indicator in extant hominids. | the aim of this study is to understand whether the shape of three sub-regions of the mandibular corpus (the alveolar arch, corpus at m1 and posterior symphysis) are useful for making taxonomic assessments at the genus and species levels in extant hominids. | 2020 | 32166734 |
| no evidence of what-where-when memory in great apes (pan troglodytes, pan paniscus, pongo abelii, and gorilla gorilla). | episodic memory is the ability to recollect specific past events belonging to our personal experience, and it is one of the most crucial human abilities, allowing us to mentally travel through time. in animals, however, evidence of what-where-when memory (hereafter, www memory) is limited to very few taxa, mostly reflecting the socioecological challenges faced in their environment. in this article, we aimed to replicate 2 studies previously conducted on birds and primates to find convincing evid ... | 2020 | 32052981 |
| trabecular variation in the first metacarpal and manipulation in hominids. | the dexterity of fossil hominins is often inferred by assessing the comparative manual anatomy and behaviors of extant hominids, with a focus on the thumb. the aim of this study is to test whether trabecular structure is consistent with what is currently known about habitually loaded thumb postures across extant hominids. | 2020 | 31762017 |
| comparative chemical analysis of body odor in great apes. | olfaction is important across the animal kingdom for transferring information on, for example, species, sex, group membership, or reproductive parameters. its relevance has been established in primates including humans, yet research on great apes still is fragmentary. observational evidence indicates that great apes use their sense of smell in various contexts, but the information content of their body odor has not been analyzed. our aim was therefore to compare the chemical composition of body ... | 2019 | 31094019 |
| why human environments enhance animal capacities to use objects: evidence from keas (nestor notabilis) and apes (gorilla gorilla, pan paniscus, pongo abelii, pongo pygmaeus). | formal training programs, which can be called education, enhance cognition in human and nonhuman animals alike. however, even informal exposure to human contact in human environments can enhance cognition. we review selected literature to compare animals' behavior with objects among keas and great apes, the taxa that best allow systematic comparison of the behavior of wild animals with that of those in human environments such as homes, zoos, and rehabilitation centers. in all cases, we find that ... | 2018 | 30024236 |
| comparing the sniffing behavior of great apes. | the importance of smell in humans is well established but we know little about it in regard to our closest relatives, the great apes, as systematic studies on their olfactory behavior are still lacking. olfaction has long been considered to be of lesser importance in hominids given their relatively smaller olfactory bulbs, fewer functional olfactory receptor genes than other species and absence of a functional vomeronasal organ. therefore, the aim of this study was to evaluate the use of olfacti ... | 2018 | 29756687 |
| the interplay of prior experience and motivation in great ape problem-solving (gorilla gorilla, pan paniscus, pan troglodytes, and pongo abelii). | many primate species have a strong disposition to approach and manipulate objects in captivity. however, few studies have investigated what primates learn during free exploration of objects in the absence of rewards, and how previous problem-solving performance influences subsequent exploration. we confronted members of each of the four nonhuman great ape species (n = 25) with the collapsible platform task that required subjects to drop a stone inside a tube to collapse a platform and release a ... | 2018 | 29708360 |
| differences in novel food response between pongo and pan. | the diversity of great ape diets requires behavioral flexibility. consequently, the exploration of potentially novel food sources is supposedly beneficial, but simultaneously, apes show high neophobia to prevent harmful and poisonous food intake. social information, such as presence of group members or observations of non-naïve, experienced individuals have been demonstrated to affect the acceptance of novel food items in primates. sociality may have evolutionary effects on the response of apes ... | 2019 | 30604887 |
| identification of genes involved in the evolution of human intelligence through combination of inter-species and intra-species genetic variations. | understanding the evolution of human intelligence is an important undertaking in the science of human genetics. a great deal of biological research has been conducted to search for genes which are related to the significant increase in human brain volume and cerebral cortex complexity during hominid evolution. however, genetic changes affecting intelligence in hominid evolution have remained elusive. we supposed that a subset of intelligence-related genes, which harbored intra-species variations ... | 2020 | 32337102 |
| placenta accreta in an oragnutan (pongo abelii) and a chimpanzee (pan troglodytes). | placenta accreta is defined as abnormal adherence of the placenta to the uterine wall. placenta accreta is recognized as a common problem in human medicine, but has apparently not been reported previously in great apes, despite similarity in their reproductive biology. a 36-year-old multiparous female sumatran orangutan (pongo abelii) and a 20-year-old nulliparous female chimpanzee (pan troglodytes), with gross uterine and histological uterine vascular changes that are characteristic of placenta ... | 2020 | 31955798 |
| congenital hypothyroidism in a bornean orangutan (pongo pygmaeus) and a sumatran orangutan (pongo abelii). | congenital hypothyroidism (ch) in humans is most commonly caused by disruption of thyroid gland development (dysgenesis) or an inherited defect in thyroid hormone biosynthesis (dyshormonogenesis). ch has not been previously documented in great apes. this report describes the clinical presentation, diagnosis, and treatment of ch in a 9-mo-old male bornean orangutan (pongo pygmaeus) and a 6-wk-old female sumatran orangutan (pongo abelii). primary ch due to thyroid dysgenesis was confirmed in the b ... | 2019 | 31260215 |
| genomes reveal marked differences in the adaptive evolution between orangutan species. | integrating demography and adaptive evolution is pivotal to understanding the evolutionary history and conservation of great apes. however, little is known about the adaptive evolution of our closest relatives, in particular if and to what extent adaptions to environmental differences have occurred. here, we used whole-genome sequencing data from critically endangered orangutans from north sumatra (pongo abelii) and borneo (p. pygmaeus) to investigate adaptive responses of each species to enviro ... | 2018 | 30428903 |
| orangutan populations are certainly not increasing in the wild. | a recent report, published by the government of indonesia with support from the food and agricultural organization and norway's international climate and forest initiative, states that orangutan populations (pongo spp.) have increased by more than 10% in indonesia from 2015 to 2017, exceeding the government target of an annual 2% population increase [1]. this assessment is in strong contrast with recent publications that showed that the bornean orangutan (p. pygmaeus) lost more than 100,000 indi ... | 2018 | 30399343 |
| the effects of sociability on exploratory tendency and innovation repertoires in wild sumatran and bornean orangutans. | it has been hypothesized that opportunities for social learning affect the size and complexity of the adult skill set of birds and mammals, their learning ability, and thus ultimately also their innovation frequency. to test these predictions we compared rates of social learning, rates of independent exploration (independent learning) and innovation repertoires between individuals of a highly sociable population of pongo abelii at suaq balimbing and a less sociable population of pongo pygmaeus w ... | 2017 | 29133851 |
| characterization and functional analysis of siah1 during skin and hair follicle development in the angora rabbit (oryctolagus cuniculus). | seven in absentia homolog 1 (siah1) is an e3 ubiquitin ligase containing a ring-finger domain and a key regulator of normal development. skin and hair follicle development is a complex and special process of morphogenesis involving multiple signaling pathways. siah1 is enriched in the wnt signaling pathway and potentially related to hair follicle cycle and skin development. this study aims to provide evidence for the role of siah1 in skin and hair development. | 2020 | 32252830 |
| decision-making flexibility in new caledonian crows, young children and adult humans in a multi-dimensional tool-use task. | the ability to make profitable decisions in natural foraging contexts may be influenced by an additional requirement of tool-use, due to increased levels of relational complexity and additional work-effort imposed by tool-use, compared with simply choosing between an immediate and delayed food item. we examined the flexibility for making the most profitable decisions in a multi-dimensional tool-use task, involving different apparatuses, tools and rewards of varying quality, in 3-5-year-old child ... | 2020 | 32160191 |
| accurate sex identification of ancient elephant and other animal remains using low-coverage dna shotgun sequencing data. | sex identification of ancient animal biological remains can benefit our understanding of historical population structure, demography and social behavior. traditional methods for sex identification (e.g., osteological and morphometric comparisons) may be ineffective when animal remains are not well preserved, when sex distinguishing characteristics have not yet developed, or where organisms do not exhibit sex-associated phenotypic dimorphisms. here we adapt a method developed for human sex determ ... | 2020 | 32107273 |
| preference for free or forced choice in sumatran orangutans (pongo abelii). | empirical investigations of humans, pigeons, rats, and monkeys have indicated that these species will select free over forced choice, even when faced with identical outcomes. however, the same has yet to be quantitatively confirmed in nonhuman great apes. this experiment is the first systematic investigation of preference for free or forced choice in great apes using a paradigm in which extraneous variables are highly controlled. three orangutans were given a choice of one of two virtual routes, ... | 2020 | 32101330 |
| object preferences in captive sumatran orang-utans (pongo abelii). | while preferences for perceptual features of objects are well studied in humans, little is known about this trait in other great apes. we therefore presented captive sumatran orang-utans (pongo abelii) with objects that differed in shape (spherical, cuboid), colour (red, green), or texture (hard, soft). overall, orang-utans preferred spherical over cuboid and red over green objects. soft objects were preferred over hard ones. however, this preference might be confounded by the decomposable chara ... | 2020 | 31693925 |
| weissella, a novel lactic acid bacteria isolated from wild sumatran orangutans (pongo abelii). | this study aimed to isolate and identify lactic acid bacteria (lab) in wild sumatran orangutans to provide more information about lab diversity derived from sumatran orangutan feces. | 2019 | 31528033 |
| the loud scratch: a newly identified gesture of sumatran orangutan mothers in the wild. | the communicative function of primates' self-directed behaviours like scratching has gained increasing attention in recent years, but their intentional use is still debated. here, we addressed this issue by exploring the communicative function of 'loud scratches' in wild sumatran orangutans. building on previous studies in chimpanzees, we examined the prediction that audio-visual loud scratches are used communicatively in mother-infant travel coordination. specifically, we examined whether indiv ... | 2019 | 31311488 |
| spatial behavior in rehabilitated orangutans in sumatra: where do they go? | wildlife restoration is one of the key components of conservation strategies, and this includes the rehabilitation and release of animals confiscated from wildlife traffickers. when primates are re-introduced, most individuals need a pre-release training to acquire the skills needed to survive in the wild. pre-release training may either negatively or positively affect primate post-release behavior and survival. post-release behavior, however, has rarely been monitored even though it is the only ... | 2019 | 31042732 |
| orangutans (pongo abelii) make flexible decisions relative to reward quality and tool functionality in a multi-dimensional tool-use task. | making economic decisions in a natural foraging situation that involves the use of tools may require an animal to consider more levels of relational complexity than merely deciding between an immediate and a delayed food option. we used the same method previously used with goffin´s cockatoos to investigate the orangutans' flexibility for making the most profitable decisions when confronted with five different settings that included one or two different apparatuses, two different tools and two fo ... | 2019 | 30759087 |
| lipoid pneumonia in an orangutan (pongo abelii) with chronic respiratory problems. | an orangutan (pongo abelii) presented with chronic respiratory problems. cytological evaluation of the bronchoalveolar lavage fluids revealed macrophages with well-circumscribed intracytoplasmic clear vacuoles and lipid droplets in the background, confirmed by oil red o staining. the findings were indicative of lipoid pneumonia. this is the first report of lipoid pneumonia in an orangutan. | 2019 | 30443913 |
| time-space-displaced responses in the orangutan vocal system. | one of the defining features of language is displaced reference-the capacity to transmit information about something that is not present or about a past or future event. it is very rare in nature and has not been shown in any nonhuman primate, confounding, as such, any understanding of its precursors and evolution in the human lineage. here, we describe a vocal phenomenon in a wild great ape with unparalleled affinities with displaced reference. when exposed to predator models, sumatran oranguta ... | 2018 | 30443595 |
| spontaneous innovation of hook-bending and unbending in orangutans (pongo abelii). | betty the crow astonished the scientific world as she spontaneously crafted hook-tools from straight wire in order to lift a basket out of vertical tubes. recently it was suggested that this species' solution was strongly influenced by predispositions from behavioural routines from habitual hook-tool manufacture. nevertheless, the task became a paradigm to investigate tool innovation. considering that young humans had surprising difficulties with the task, it was yet unclear whether the innovati ... | 2018 | 30410111 |
| perineal repair of a full-thickness rectal prolapse in a wild sumatran orangutan (pongo abelii). | a delorme's procedure perineal surgical repair was performed in a wild adult male sumatran orangutan (pongo abelii) with a chronic persistent rectal prolapse that had been unsuccessfully treated by 6 previous surgeries. the rectal prolapse did not recur, and the orangutan was successfully released to the wild, 6 weeks later. | 2019 | 30307044 |
| conflict resolution in socially housed sumatran orangutans (pongo abelii). | peaceful conflict resolution strategies have been identified as effective mechanisms for minimising the potential costs of group life in many gregarious species, especially in primates. the knowledge of conflict-management in orangutans, though, is still extremely limited. given their semi-solitary lives in the wild, there seems to be barely a need for orangutans to apply conflict management strategies other than avoidance. however, because of the rapid loss of orangutan habitat due to deforesta ... | 2018 | 30083451 |
| treatment of disseminated strongyloides spp. infection in an infant sumatran orangutan (pongo abelii). | strongyloides nematodes have been reported in all species of great apes with orangutans ā¤5 years old most susceptible to severe clinical disease. this brief communication describes the first published case of antemortem diagnosis and treatment of disseminated strongyloidiasis in a clinically affected 5-month-old sumatran orangutan (pongo abelii). | 2018 | 29493782 |