western lowland gorillas (Gorilla gorilla gorilla) depends on specific social factors such as the age of the gorilla and age and sex of the partner (Brown, 1988). Younger gorillas have been shown to play more frequently with peers of a similar age, and the general frequency of play typically declines as gorillas mature (Brown, 1988). Partner preference has also been shown based on sex, and male-male and male-female play dyads typically occur more frequently than female-female dyads (Brown, 1988; Palagi et al., 2007). These play dyad structures are reasonable observations when considered from a gorilla social structure standpoint. Both male and female gorillas emigrate from their natal group, and while females form strong social bonds with the adult males of their new group, they do not tend to form strong social bonds with the other adult females (Harcourt, 1979; Watts, 1996). As adults, the male-male bond in gorillas is central, which differs from other primate species that have a strong matrilineal influence. Male gorillas may also spend part of their life living in all male bachelor groups; therefore, male-male and male-female playing would be more frequently observed than female- female dyads. These results are consistent with other studies that examine sex differences in play among gorillas (Maestripieri & Ross, 2004; Palagi et al., 2007) and remain consistent with the predictions of the social skills hypothesis.
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repertoire of social activities, great apes represent a valuable animal model to investigate the functional and evolutionary characteristics of the cerebral lateralization for the processing of social stimuli. We observed the spontaneous social behaviors in a biological family group of peer-reared western lowland gorillas (Gorilla gorilla gorilla) and in a colony of captive zoo- living chimpanzees (Pan troglodytes), particularly focusing on the side of the body exposed to conspecifics that were in close proximity. Unlike previous studies of non-human primates (Casperd & Dunbar, 1996; Baraud et al, 2009), we did not consider the right/left visual field, as this kind of measure might be more suitable for animals with laterally placed eyes and small binocular overlap (Robins et al, 1998). Instead, our analysis was focused on the lateral hemi-field of the body that the focal subject presented to conspecifics. This study presents a new methodological approach to the investigation of social laterality in primates. We suggest that lateral positioning is likely to reflect a hemispheric specialization for the processing of social stimuli and represents a heightened state of arousal, which would be inherently
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lowland gorilla following the divergence of the Gorilla and Homo-Pan lineages. The age of the gorilla-specific lineages ranges from 6.5-6.71 million years ago based on a baseline divergence of 7 million years ago for the most recent common ancestor of Gorilla and Homo-Pan. This indicates that all of the identified subfamilies originated around the time of the speciation event that separated these two lineages. This result is consistent with the ongoing propagation of these subfamilies before, during, and after the speciation event at a relatively constant rate. This indicates that the ‘master genes’  from which these subfamilies are derived already existed and were retrotranspositionally active prior to the aforementioned speciation event, and have remained active subsequently. Examination of Alu elements indicates retrotranspositionally active elements are relatively rare, and that most Alu activity is the result of a small num- ber of ‘master’ copies engaging in retrotranspositional activity over time . Our results suggest that the 10 gorilla-specific AluY subfamilies identified in this study diverged and are still diverging from master elements already present in the gen- ome of the common ancestor of the Gorilla and Homo-Pan lineages. A table listing each subfamily, the ‘master gene’ or ancestral Alu subfamily from which it was likely derived, the % divergence from the consensus sequence of the master element, copy number, and suggested age of the most recent common ancestral element are available in the Additional files section of this paper as Additional file 3.
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Age showed an effect on not only the richness and Shannon diversity of the reported microbial taxa, but also the variation between individuals in the same age group. Different microbial taxa appear to dominate each age group over others, although more individuals are needed in each age group to determine whether these trends are significant. Cloacibacillus was dominant in gorillas aged 27-31 and 41, which included individuals housed at Denver and Riverbanks zoos. No individual at NC Zoo fell within this age range, and their eldest individual (45 years of age) did not show the higher abundance of Cloacibacillus. The adolescent at Denver Zoo showed a striking similarity to the adults. This may suggest that the gorilla microbiome matures by the age of two, a similar colonization timeframe to lemurs (McKenney et al., 2015). More data is needed to verify the age of microbiome maturity in gorillas but should correlate of the age of weaning (McKenney et al., 2015). Prevotella and Prevetelleceae show high relative abundance for all ages pointing towards their importance in digesting the diet gorillas consume.
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By using genetic analysis to monitor multiple groups over several years, we indirectly observed the dynamics of group formation, group dissolution and individual movements in WLGs. As we have observed not only harem groups but also probable multi-male and mixed-sex non-reproductive groups at Loango, our results add to the growing body of evidence suggesting that the structure of WLG society contains vari- ous types of social units (Gatti et al., 2004; Levréro et al., 2006; Robbins et al., 2004). Furthermore, not all males in the reproductive groups are sons of the silverback, atypical for classical harem social units (Fig. 2b). Over a 5-year period, while genetically monitoring 18 social units, we inferred the dissolution of two groups, the formation of two groups, the death of one male and the dispersal of 13 individuals between social units. Taking into account the limits of our approxi- mated number of recorded gorilla social unit years as detailed in the methods, the rate of group dissolution (2 in 19 social unit years: 11 %) is similar to that observed at Mbeli Bai (5 dissolutions in 63 gorilla group years: 8 %) (Robbins et al., 2004), as is the rate of female transfer: 8 cases in 19 social unit years (42 %) at Loango and 27 incidences in 63 group years (43 %) at Mbeli Bai (Stokes et al., 2003). It is impor- tant to note that these results represent the minimum number of dispersal events, social unit formations and dissolutions and that with increased sampling it is likely that more such events would be revealed. Similarly, this suggests that our rates of group dissolution and female transfer underestimate the true rates at Loango.
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GgorAdV-B8 was detected in two fecal samples from wild gorillas in Gabon and in one sample from Münster. Its hexon sequence revealed the highest percentage of identity (86.5%) to SAdV-21 (chimpanzee HAdV-B). GgorAdV-B9 was only amplified from captive gorillas (two fecal samples from Münster) and showed 88% iden- tity to SAdV-29 (chimpanzee HAdV-B). The GgorAdV- B7 to -B10 Hex-loop2 sequences and closely related sequences of published gorilla, chimpanzee, bonobo and human HAdV-B viruses were subjected to phylogenetic analysis as described above. In the tree, the HAdV-B viruses segregate into several subclades with members of two, three or four host species (human, chimpanzee, bonobo and gorilla) (Figure 5). This mixed clustering was also observed upon analysis of the nearly complete hexon gene (2.7 kb; Figure 4a) with GgorAdV-B7 only. It was partially visible in the penton base tree (Figure 4d) and Table 2 Adenoviruses, accession numbers and hosts
Surveys show that zoo-housed great apes occasionally interact with local wildlife. Bonobos and chimpanzees interact aggressively with and sometimes consume wildlife. Gorillas may also interact with local wildlife, but less often in an aggressive way and consumption is rare. Here we report the case of an adolescent female western lowland gorilla (Gorilla gorilla gorilla) in Apenheul Primate Park (Apeldoorn, The Netherlands) that persistently catches and handles ducklings. Prior to observations four possible explanations were proposed, which are not mutually exclusive: play, meat eating, need for abnormal plucking, and allomothering. On eight occasions the female was observed to actually catch ducklings (9 ducklings in total) and the minimum number handled was 19 unique ducklings. She handed ducklings on 10 out of 17 observation days. Ad libitum observations showed that the female spent much time plucking the feathers of the duckling, handling it carefully. In addition, she regularly placed a duckling on her back during locomotion. Eating of a carcass was not observed and playing with a carcass was very rare. Based on these observations, it is proposed that allomothering and abnormal plucking, rather than meat eating or play, may explain this idiosyncratic behaviour. This female probably invented the behaviour herself.
Stokes, E. J., Strindberg, S., Bakabana, P. C., Elkan, P. W., Iyenguet, F. C., Madzoke, B., Malanda, G. A., Mowawa, B. S., Moukoumbou, C., Ouakabadio, F. K., and Rainey, H. J. (2010). Monitoring great ape and elephant abundance at large 144 spatial scales: measuring effectiveness of a conservation landscape. PLoS One, 5(4), e10294, doi:10.1371/journal.pone.0010294. Tagg, N., and Willie, J. (2013). The Influence of Transect Use by Local People and Reuse of Transects for Repeated Surveys on Nesting in Western Lowland Gorillas (Gorilla gorilla gorilla) and Central Chimpanzees (Pan troglodytes troglodytes) in Southeast Cameroon. International Journal of Primatology, 1-17.
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This project aims to compare the community composition and fermentation activity of gastrointestinal bacteria isolated from Western lowland gorilla (Gorilla gorilla gorilla), chimpanzee (Pan troglodytes), Hamadryas baboon (Papio hamadryas), and binturong (Arctictis binturong) fecal samples. The primate species were chosen to represent feeding strategies across the omnivorous spectrum. In the wild, Western lowland gorillas consume a diet comprised mainly of leaves and plant material, while free-ranging chimpanzees forage for fruits; both supplement their diet with high-protein insects and small prey. Hamadryas baboons are more opportunistic, feeding on a wider variety of fruits and vegetation and a higher percentage of small prey. Binturongs are carnivores, but like chimpanzees they consume up to 90% fruit in situ. Host behavior and gastrointestinal morphology are suspected to have an impact on the microbiota associated with each species. By characterizing the demographics of bacterial populations as well as their fermentation profiles, we hope to better understand the
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Western lowland gorillas (Gorilla gorilla gorilla) are among the most studied nonhuman primates. However, managing them in captivity is not without its challenges. Understanding individual differences between gorillas, as well as differences in group dynamics, may be of high value for more efficient captive management. The capacity to predict behaviour may be especially useful, particularly in terms of affiliative and aggressive behaviours. For these reasons, we designed a brief study that investigates the relationship between gorilla personality and social dynamics. Our study was conducted in Paignton Zoo Environmental Park (UK), in May 2015. Behavioural observations were carried out on an all-male gorilla group, comprising one silverback and four maturing blackbacks. Behaviour was recorded using scan sampling, with an instantaneous recording technique. Simultaneously, we used all occurrence sampling to record social behaviours of interest: affiliative behaviour (social resting, social playing) and agonistic behaviour (displacement, aggressive behaviour), with the initiator and the recipient recorded for each event. Additionally, the main gorilla keeper rated each gorilla on the Gorilla Behavior Index (GBI), a personality assessment instrument that identifies four personality factors - Extroverted, Dominant, Fearful, and Understanding. Gorillas with higher scores on the Extroverted factor exhibited higher proportions of social behaviour in their activity budgets, and were more likely to be chosen to rest near. Individuals with higher Dominant scores were less likely to be displaced, while higher Understanding scores were correlated with a lower likelihood of initiating aggressive interactions, and a higher proportion of solitary behaviour. To better understand the relationship between gorilla personality and behaviour, we recommend the use of a hierarchical approach to studying personality. We anticipate that a higher level of specificity will enable more accurate predictions of behaviour, thereby providing a useful tool for gorilla captive management.
Western lowland gorillas (Gorilla gorilla gorilla) are infected with a simian immunodeficiency virus (SIVgor) that is closely related to chimpanzee and human immunodeficiency viruses (SIVcpz and HIV-1, respectively) in west central Africa. Although existing data suggest a chimpanzee origin for SIVgor, a paucity of available sequences has precluded definitive conclusions. Here, we report the molecular characterization of one partial (BQ664) and three full-length (CP684, CP2135, and CP2139) SIVgor genomes amplified from fecal RNAs of wild-living gorillas at two field sites in Cameroon. Phylogenetic analyses showed that all SIVgor strains clustered together, forming a monophyletic lineage throughout their genomes. Interestingly, the closest rela- tives of SIVgor were not SIVcpzPtt strains from west central African chimpanzees (Pan troglodytes troglodytes) but human viruses belonging to HIV-1 group O. In trees derived from most genomic regions, SIVgor and HIV-1 group O formed a sister clade to the SIVcpzPtt lineage. However, in a tree derived from 5 ⴕ pol sequences ( ⬃ 900 bp), SIVgor and HIV-1 group O fell within the SIVcpzPtt radiation. The latter was due to two SIVcpzPtt strains that contained mosaic pol sequences, pointing to the existence of a divergent SIVcpzPtt lineage that gave rise to SIVgor and HIV-1 group O. Gorillas appear to have acquired this lineage at least 100 to 200 years ago. To examine the biological properties of SIVgor, we synthesized a full-length provirus from fecal consensus sequences. Transfection of the resulting clone (CP2139.287) into 293T cells yielded infectious virus that replicated efficiently in both human and chimpanzee CD4 ⴙ T cells and used CCR5 as the coreceptor for viral entry. Together, these results provide strong evidence that P. t. troglodytes apes were the source of SIVgor. These same apes may also have spawned the group O epidemic; however, the possibility that gorillas served as an intermediary host cannot be excluded.
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Gorilla (www.gorilla.sc) is an online experiment builder whose aim is to lower the barrier to access, enabling all researchers and students to run online experiments (regardless of programming and networking knowledge). As well as giving greater access to web-based experiments, it reduces the risk of introducing higher noise in data (e.g., due to misuse of browser-based technology). By lowering the bar- rier, Gorilla aims to make online experiments available and transparent at all levels of ability. Currently, experiments have been conducted in Gorilla on a wide variety of topics, includ- ing cross-lingual priming (Poort & Rodd, 2017), the provision of lifestyle advice for cancer prevention (Usher-Smith et al., 2018), semantic variables and list memory (Pollock, 2018), narrative engagement (Richardson et al., 2018), trust and rep- utation in the sharing economy (Zloteanu, Harvey, Tuckett, & Livan, 2018), how individuals’ voice identities are formed (Lavan, Knight, & McGettigan, 2018), and auditory percep- tion with degenerated music and speech (Jasmin, Dick, Holt, & Tierney, 2018). Also, several studies have preregistered reports, including explorations of object size and mental sim- ulation of orientation (Chen, de Koning, & Zwaan, 2018) and the use of face regression models to study social perception (Jones, 2018). Additionally, Gorilla has also been mentioned in an article on the gamification of cognitive tests (Lumsden, Skinner, Coyle, Lawrence, & Munafò, 2017). Gorilla was launched in September 2016, and as of January 2019 over 5,000 users have signed up to Gorilla, across more than 400 academic institutions. In the last three months of 2018, data were collected from over 28,000 participants—an average of around 300 participants per day.
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The GORILLA project is also endorsed and supported by the Department of Linguistics at Indiana University. We are grateful to the interns and visiting students at LIN- GUIST List in the summer of 2015 for their help with corpora and the initial definition of the GORILLA infras- tructure. Many graduate students from the Indiana Uni- versity Department of Linguistics have participated and contributed to the resources. We are in particular grate- ful to Aaron Albin, Seyed Asghari, Edvard Bigbaev, Zac Branson, Petar Garžina, Clara García Gómez, Levi King, and Alec Wolyniec for their help and support. Michael Abramov helped us transcribe and time align Chatino in ELAN. Anya Quilitsch and Avi Lang invested a lot of time in transcription and annotation of the Yiddish speech cor- pus, and Dov-Ber Kerler provided us with the material and valuable suggestions. Raphael Finkel from the University of Kentucky provided us with a Yiddish dictionary and pho- netic transcriptions, as well as tools for the transfer of He- brew script Yiddish to YIVO romanization. All editors and graduate assistants of LINGUIST List were maximally helpful with suggestions, comments, contributions: Sara Couture, Andrew Lamont, and Anna White.
Data were collected between July and September 2012 from two free-ranging, habituated groups of western lowland gorillas in the Nouabalé-Ndoki National Park in the Republic of Congo. The Mondika study site is located at the boundaries of the Central African Republic and the Republic of Congo [for more detailled information see 27]. Two gorilla groups were followed daily from 7am until 4:30 pm by EML or an assistant (sampling rule: behavior sampling; recording rule: continuous recording, see ). The groups consisted of eleven and thirteen individuals and were observed for approximately 450 and 150 hours, respectively. Our recordings were made with a Sony PCM-M10 digital recorder (equipped with a directional Rode M3 microphone) at a sampling rate of 44.1 Hertz and 16 bits accuracy. Recordings were transferred digitally onto a MacBook Pro (OS X 10.6.8) and quantitative analyses of calls were carried out using Praat software (version 5.3.32, Boersma & Weenink, 2007). We used the following setting for measurements: Spectrogram settings: view range=0.0 to 3000 Hertz, window length=0.05 seconds, dynamic range=50 dB; Intensity settings: view range=50-100 dB.
the subnasal anatomy, the depictions found in Ward and Kimbel (1983), McCollum et al., (1993), and McCollum and Ward (1997) are nevertheless misleading as to its actual morphology. Ultimately, McCollum and Ward (1997) concluded that the qualitative characters used to discriminate extant taxa based on the subnasal anatomy did not vary appreciably with sex or age, with the exception of individuals in the earliest stages of ontogeny (McCollum and Ward, 1997). Quantitative characters, with minor exceptions, were also said not to vary with age, again with the exception of individuals in the earliest stages of ontogeny (McCollum and Ward, 1997). However, it appeared that during the earliest stages of ontogeny the nasal cavity floor is free of substantial topographic relief that is diagnostic of many extant hominoid taxa (McCollum and Ward, 1997). The anterior portion of the maxilla rotates upwardly during development, altering the angulation of the premaxillae/anterior alveolar processes and the palatine processes and the relationship between the two elements (McCollum and Ward, 1997). This rotation is accompanied by an extensive resorption of the floor of the anterior nasal cavity, ultimately leading to an increase in the topographic relief in many adult hominoids (McCollum and Ward, 1997). McCollum and Ward (1997) concluded that only at this early stage of ontogeny did the morphology of the subnasal anatomy cease to discriminate between extant hominoid taxon. Differences in craniofacial orientation, the size and inclination of the incisors and the vascular anatomy were found to be the major influences on variation in the subnasal anatomy and as such, McCollum and Ward (1997) conclude that the subnasal anatomy of Pongo is highly derived relative to the other extant hominoids. However, they argue there is no evidence that the morphology exhibited by Gorilla represents the primitive “hominoid pattern” as argued by some researchers (see: Chapter 4, The Subnasal Anatomy of the Extant Hominoids) (McCollum and Ward, 1997; contra Begun, 1992; 1994). Differences in the subnasal anatomy due to sexual dimorphism were found only in Pongo and Gorilla, and were a result of the differences in development due to delayed sexual maturation in males (McCollum and Ward, 1997).
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Phylogenetic relationships can be read from genome comparison. Mitochondrial pseudogenes within the nuclear genome, that originate from mtDNA, provide an ideal marker for tracing hybridization events over large evolutionary time scales, and the ps5 NUMT in Gorilla , Homo and Pan has preserved a record of an event in hominin evolution that, when combined with the fossil record as well as genome analyses as a whole, shows a clear trail of introgression from Gorilla at the Pan-Homo split, and that this hybridiza- tion was what caused the speciation of hominins.
Closely related to semantic plausibility is selec- tional preference (Resnik, 1996) which concerns the semantic preference of a predicate for its argu- ments. Here, preference refers to the typicality of arguments: while it is plausible that a gorilla rides a camel, it is not preferred. Current approaches to selectional preference are distributional (Erk et al., 2010; Van de Cruys, 2014) and have shown lim- ited performance in capturing semantic plausibil- ity (Wang et al., 2018).
The subject of the study is Koko, a female western lowland gorilla (Gorilla gorilla gorilla) who was 37 to 39 years of age during the reported observations. Koko was born in 1971 at the San Francisco Zoo, but became ill at six months and was moved from the zoo’s gorilla enclosure to be cared for by humans and nursed back to health (Patterson & Linden 1981). At the age of one year, she came under the care of the second and third authors (FGP, RHC). At this time, Koko began lifelong tutelage in a sign system derived from American Sign Language, as well as immersion in spoken English. Over the course of her life, play with musical instruments has been a common interactive activity between Koko and her care- givers, and as such, one that has been encouraged and rewarded. In general, Koko’s novel breath-related and vocal behaviors have been subject to demon- stration, molding and various forms of reinforcement including food and verbal praise, but have not been specifically trained by operant conditioning proced- ures.
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Importantly, gorillas and chimpanzees are highly endan- gered species which continue to be hunted, especially in west central Africa, and remain a potential source of human infec- tions (21). SIVs from apes are now known to have crossed the species barrier to humans on at least four occasions in west central Africa (14, 26). Given the recent discovery of the HIV-1 group P lineage in a Cameroonian woman in France, it would not be surprising if additional cases of SIVcpz or SIVgor cross-species transmissions had occurred, especially in geo- graphic regions where these viruses are most prevalent and where hunting pressure is high. As shown for the group P virus-infected patient, SIVcpz/SIVgor infections are likely to be detected by commercial HIV antibody screening assays. However, HIV screening in Africa is still suboptimal, and se- rological tests with low sensitivities for group M, and especially for HIV-1 group O, are still used in this part of the world (1, 10, 25, 42). In addition to the use of assays with low sensitivi- ties, poor serological results are also related to the high turn- over of trained personnel, suboptimal storage conditions, fail- ure of the cold chain during transport, use of tests after the expiration date, etc. (3). It is thus possible that in regions TABLE 6. SIV infection in wild chimpanzee and gorilla populations from different field sites in this and previous surveys in Cameroon
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Overall, the scaled data in the Jackknifed classification matrix has a lower percentage of specimens being classified correctly compared to the unscaled. Gorilla has the largest percent correct for each variable, except for the scaled premolars where it has the second largest percentage. This can be interpreted that Gorilla is the most distinguishable taxon when compared to the others. Homo and Pan are frequently misclassified as one another on the classification matrix. Sts has a 0% correct classification rate in all variables, premolars and molars, unscaled and scaled. This means that Sts includes a large variation and the small sample size from this site further decreased classification and significant differences with other groups. Both Sts and StW classify 100% as StW for premolars, unscaled and scaled. This means that Australopithecus exhibits distinction in the size and shape of premolars compared to the extant species. Using this analysis, the null hypothesis is not rejected as the two extinct species are frequently classified within the same group.
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