Thesis (Ph. D.)--Columbia University, 1933. / Vita. Published also without thesis note. "Printed in England." Bibliography: p. [369]-381.

The loud songs of gibbons (Hylobatidae) usually consist of a duet by the mated pair delivered each morning. These songs can transmit over a kilometre through dense forest habitat and therefore presumably play a role in long-distance communication. There is some evidence to suggest that gibbons use song in contexts other than their daily duets, such as predation, but these songs have not been well studied. Close- range communication is also relevant for gibbons, but these quieter calls have completely escaped any detailed observation. The responses of wild white-handed gibbons (Hylobates lar) to simulated visual and acoustic predators (tiger, clouded leopard, reticulated python and crested serpent eagle) were studied in Khao Yai National Park, Thailand to address the lack of empirical data about these important events. Little is known about gibbons’ anti- predatory behaviour in general, and simulated predator encounters provided an opportunity to investigate these responses as well. Results showed that gibbons used song as part of their anti-predator strategy and that subtle combinatorial changes were meaningful to conspecifics. They also showed marked behavioural changes in the short-term, and some evidence of longer-term changes as well. Quiet calls were also part of the gibbons’ response repertoire with the hoo call being particularly relevant. Hoos were used as a prelude to singing both normal duets and predator songs, but there were consistent differences between each context. Hoos were also delivered independently in a number of other contexts outside predation. When analysed, these hoos showed consistent contextual differences in a number of spectral parameters. Within the duet context, important contextual subtleties were evident also revealing a remarkable vocal plasticity. In addition, gibbons voluntarily attended to specific vocal elements of other gibbon duets, indicating that certain sequences are more pertinent than others. Results suggest both gibbon song and gibbon hoos are powerful communication tools that reliably reference external objects and events; this ability is also a critical feature of human language.

Thesis (B.A. Hons.)--University of Adel., 1967. / [Typescript].

Cognitive research is the study of mental processes that guide behaviors and decision making in animals and humans. By studying the cognitive attributes of species within a taxon, as in the case of the order Primates, one can identify behavioral and cognitive components characteristic of certain taxa, such as families, species, or perhaps individuals. This allows us to estimate when and where these cognitive abilities arose in evolutionary history and to hypothesize about their cause and evolutionary origins. Episodic memory or episodic cognition gives an organism the ability to recall declarative forms of memories, which allows one to recall past experiences/histories and can then be used to teach, learn, or even promote socialization in many species (Dunbar, 2011). Additionally, it involves how that organism applies such memories to the past and future, thus allowing the organism to project “oneself” into time and space (Clayton, 2017). This is known as mental time travel or future-oriented memory. Scholars maintain that Homo sapiens (e.g. humans) have the most advanced degree of episodic memory (Suddendorf & Corballis, 2007; Tulving, 1985). However, when and how episodic and future-oriented memory evolved in the primate lineage, and if nonhuman and human episodic memory are comparable, is still unknown. Studying the foundation of this complex form of cognitive memory in a basal group of extant hominoids (apes), allows us to hypothesize about the phylogenetic, social, and perhaps objective mechanisms that were necessary for this complex cognitive system to evolve and persist throughout the primate lineage. Our current understanding of episodic memory is ambiguous, concerning what parts of the brain are truly utilized in this system and to what degree of episodic/future-oriented memory abilities are found throughout the animal kingdom. The current understanding is that very few taxa genuinely exhibit episodic memory capabilities (Allen & Fortin, 2013; Crystal & Suddendorf, 2019). The purpose of this research was to examine episodic/future-oriented memory in nonhuman primates, specifically in hylobatids (Family Hylobatidae), also known as small Asian apes, the gibbons, and siamangs. Hylobatids are small bodied, arboreal apes native to the tropical forests of Southeast Asia (Fleagle, 1976). Although apes, hylobatids have very different social, physical, and ecological distinctions from their larger-bodied cousins, the great apes (Reichard et al., 2016). These differences have often been used as a justification as to why hylobatid behavior and cognition have been postulated by some as “inferior” to the larger bodied great apes (Russon, 2004b; Tomasello & Call, 1997). However, without scientific evidence to back up this claim, we are still very unaware of the actual cognitive capabilities of these very cryptic small apes. In total, 12 hylobatid subjects were included in this study. Hylobates, Hoolock, Nomascus, and Symphalangus were used as representatives to investigate the episodic/future-oriented memory system of hylobatids by participating in a series of noninvasive, interactive, digital cognitive tasks presented on touchscreen technology and digital testing software. Subjects varied in age, sex, and life-histories and consisted of five different species, Symphalangus syndactylus, Hylobates pileatus, Hylobates mooloch, Hoolock leuconedys, and Nomascus leucongenys, within the four genera that make up the family Hylobatidae. To date, this is one of the largest and extensive cognitive studies done with hylobatids, and to my knowledge the only study investigating components of their episodic/future-oriented memory. The cognitive tasks employed in this study were a digitally based Paired Associates Learning Task (PAL) and Future-Oriented Memory Task (FOM). The PAL task was created by Cambridge Cognition, designed to assess acute visual episodic memory, and was employed using their Monkey CANTAB software (Cambridge Cognition). The FOM task was chosen to evaluate multiple aspects of episodic/future-oriented memory, including the “what, when, and where” paradigm, and assessment of executive function and anticipatory behavior of future-oriented memory associated with the episodic memory system. The digital portion of the FOM task was commissioned and designed by an independent software developer and was created using Python and Tkinter tool kit. Only one of the subjects (Jagger) chose to participate and complete the training procedure of the PAL task but did not meet the testing threshold to move on to the data collection portion of the task. All the other subjects attempted to participate in the PAL task but lost interest and failed to participate (not interacting with the touchscreen when PAL task was presented) after approximately ~<4 training sessions. Conversely, all subjects chose to participate in the FOM task in which three of the twelve participants performed above chance (>50%) in the task. With three subjects performing well above the predetermined threshold of >50% in the FOM task, which utilizes higher cognitive control including components of episodic/future-oriented memory, it can be established that hylobatids most likely possess the same cognitive hardware regarding complex cognitive memory as those of other extant apes. Thus, this study provides further evidence that complex cognition, including advanced episode-like/future-oriented memory capabilities, were present in the last common ancestor of all apes. Furthermore, subjects’ performances were statistically analyzed to see if age, sex, species, and or life history (LH) had an impact on task performance. There was no statistical significance between age, sex, species and/or LH for the individuals in this study, but this is most likely due to the smaller sample size and/or “uneven” number of individuals occupying each category. This is common in nonhuman primate cognition studies with ape subjects due to their endangered species status and scarcity in captive settings supporting cognitive research. The knowledge obtained by this research is significant to many different biological realms. In one aspect, this information strengthens our understanding of the cognitive traits the basal ancestor of all apes may have exhibited, therefore contributing to our understating of human cognitive origin. Furthermore, by understanding the cognitive attributes of a different species, we can further investigate their behavior and “species-specific” intelligence. For example, in-situ animal rehabilitation and reintroduction programs can use the results of this research to help maintain semi-captive populations while promoting educational programs, which can prevent human-wildlife conflicts. Additionally, both in-situ and ex-situ organizations/programs such as zoos, sanctuaries, laboratories, and rehabilitation centers can use the same information to design educational programs to promote animal welfare and conservation to the public, while simultaneously establishing new husbandry and enrichment protocols, which will promote progressive animal welfare (Cronin et al., 2017; Whitehouse et al., 2013). Note: The term hylobatid(s), gibbon(s), siamang(s), and small ape(s) are used in unanimity throughout this dissertation. All usage of such terms refers to an animal(s) that belongs to primate the family Hylobatidae.

Master of Landscape Architecture / Department of Landscape Architecture/Regional and Community Planning / Mary Catherine E. Kingery-Page / The primary reasons for the existence of contemporary zoological parks are presented as conservation and conservation education. But in reality, human entertainment is the primary function of traditional zoos. There is a moral dilemma behind the practice of removing wild animals from their native habitats and holding them captive, primarily for the purpose of human entertainment and education. Exhibits designed with these human desires in mind never completely meet the needs of the animal. An exhibit designed with conservation in mind can fully address animal needs. The moral dilemma of keeping wild animals captive can be reconciled if the purpose of conservation shifts to the forefront of exhibit design. The term conservation, in this setting, refers to a habitat where a healthy, captive population can be sustained. Conservation means acquiring an in-depth understanding of an animal species and combining it with thoughtful, insightful design that responds to the species’ needs first. Secondary design considerations include facilitating the work of the animal keeper and visitor education and recreation. The keeper plays an important role in the health and well-being of the animal; a functional workplace is essential to the keeper’s job. The visitor plays an essential role in maintaining the funding that supports the zoo. In order for zoos to maintain adequate funding, they need visitors. To make this experience mutually worthwhile, exhibit design must create an experience that visitors want to be a part of, and the exhibit should impart an educational message to these visitors. This conservation-minded approach results in an exhibit that will serve primarily as a conservation facility. The exhibit is better suited to the animal by encouraging natural behavior and more accurately recreating natural habitat. A conservation exhibit can also fulfill the secondary purpose of human education by providing the visitor with a much richer depiction of the animal in its natural state, as well as showing visitors the need for species conservation.

Habil.-Schr.--Bamberg--Univ., 1996. / Bibliogr. p. 215-245.

This research investigated a number of issues regarding hepatitis B virus (HBV) in the silvery gibbon (Hylobates moloch). Due to the relatively recent discovery of the virus in nonhuman primate populations, specific knowledge of the biological behaviour of the virus is presently lacking, with current information largely extrapolated from the behaviour of HBV in human infections. In order to manage the captive and wild populations of this critically endangered species, information regarding the behaviour of the virus in gibbons and the likely impact of the viral infection is essential. The research was performed at Perth Zoo, with the study population consisting of the current and historical members of the zoo’s silvery gibbon colony. Because this gibbon species is critically endangered, the study was conducted with minimal intervention to the population with samples collected largely on an opportunistic basis from a small study population. Review of the history of the virus within the Perth Zoo colony provided epidemiological evidence to indicate vertical transmission in three gibbons (Hecla, Uban and Jury). It would appear that vertical transmission is the primary mode of transmission leading to dispersal of the virus through the captive population of silvery gibbons. Elevated concentrations of the liver enzymes alanine aminotransferase and aspartate aminotransferase were found in three gibbons (Perth 2, Uban and Jury), and may suggest a pathogenic role of the virus in this species. Histological examination of the livers of Uban and Perth 2 failed to demonstrate definitive evidence of cirrhosis, however mild fibrosis was seen in both cases and may represent an early stage of liver pathology associated with chronic hepatitis B infection. The vaccination protocol developed at Perth Zoo was successful in preventing neonatal transmission of the virus from a high infectivity carrier mother in at least two individuals, and was also successful in producing a protective level of immunity against the virus in all three of the individuals tested. Sequencing of the complete hepatitis B genome from one gibbon (Hecla) revealed that she was infected with GiHV (Gibbon hepatitis B virus), an indigenous strain of HBV previously identified in a number of gibbon species, but not previously confirmed in the silvery gibbon. Hecla's strain of HBV was shown to be more closely related to other nonhuman primate strains of HBV than to any of the human strains of HBV. 100% nucleotide similarity to two of Hecla’s siblings indicates that infection in all three animals was the result of vertical transmission from their mother. Partial sequencing of the virus from a second gibbon (Uban) identified another strain of GiHBV which supports the results of the epidemiological study. Neither gibbon showed a high sequence similarity to the virus sequenced from Ivan, the father of the third carrier gibbon (Jury), although only limited sequence data was available from Ivan. Consequently it is likely that at least three different strains of GiHBV are present within the silvery gibbon population. The information contained in this thesis will assist in the understanding and management of hepatitis B infection in silvery gibbons, as well as the numerous other species of nonhuman primates now shown to be susceptible to this virus.

texte remanié de: Th.--Lettres--Paris, 1904. / Notes bibliogr. Bibliogr. p. 113-116.

Thesis (MSc)--Oxford Brookes University, 2005. / "Date of submission: 31st October 2005"--title page. Title from initial PDF page image (viewed October 5, 2006). Includes bibliographical references (p. 45-49).

Thesis (MSc)--Oxford Brookes University, 2005. / "2005"--title page. Title from initial PDF page image (viewed October 5, 2006). Includes bibliographical references (p. 68-79).