Theseshttp://hdl.handle.net/10034/6230442024-03-29T09:25:08Z2024-03-29T09:25:08ZThe Social System, Behaviour and Communication of the Golden Monkey (Cercopithecus mitis kandti)Wiper, Susan M.http://hdl.handle.net/10034/6280892023-09-23T01:42:28Z2020-12-01T00:00:00ZThe Social System, Behaviour and Communication of the Golden Monkey (Cercopithecus mitis kandti)
Wiper, Susan M.
Forest guenons live in polygynous groups where males disperse on reaching sexual maturity and females remain within their natal group for life. During the mating season, the resident male regularly faces reproductive competition from extra-group males leading to extreme male-male competition for access to females. The golden monkey (Cercopithecus mitis kandti) is a little-understood, endangered guenon endemic to the Virunga Massif and Gishwati-Mukura National Park (Rwanda), known to live in large groups.
The aim of this study was to provide the first behavioural account of this species and to describe and quantify its social system and communication. Behavioural and spatial data were collected five days a week over 15 months, using focal, instantaneous point samples and ad libitum sampling, from the habituated Kabatwa group in the Volcanoes National Park. A total of 31 adult males were individually identified within the home-range, and categorised as resident (n=11), transient (n=4), influx (n=10) or non-resident (n=6). Elo-ratings showeda consistently stable, tolerant, egalitarian hierarchy in resident males, who displayed low levels of non-contact aggression with more severe agonism directed towards extra-group males. Social network analysis revealed closer spatial relationships between resident males during the non-mating season in the forest and consistent agonistic networks.
The mating season, defined through behavioural observations and estimating conception based on birth dates, extended over 5 months and females were observed copulating outside their conception window. Males followed females and both sexes mated with several partners over the season; the use of gestural displays were common in this reproductive context, as well as in agonistic contexts. The highly seasonal births coincided with bamboo shooting season when the group spent the majority of time in closed bamboo, with increased ground feeding; ground-feeding was frequent in this population (28% overall), and also reflected foraging for potatoes in agricultural land adjacent to the forest. The group spent about 50% of their time feeding; bamboo plant parts constituted 65.3% of their foraging effort throughout the year rising to 81.4% on bamboo shoots alone when they were available.
Males exhibited a wide variety of sex-specific calls in different contexts; with some related to dominance rank. Vocalisations were examined through GLMMs and these were often different in form or context compared with other guenons, notably the single and double boom, nasal scream and male grunt. In summary, golden monkeys observed in this study had a multi-male, multi-female social organisation; both sexes were promiscuous during the mating season, and births were highly seasonal. Resident males were tolerant of each other, exhibited a stable egalitarian hierarchy with a broad communication repertoire including sex specific calls and gestures. Discussion focuses on comparison with other guenons, the unusually large group size and the unique, all-year-round, multi-male society observed in this golden monkey group. Further research is warranted on other groups, to explore female social structure and relationships, behavioural development, and to establish an understanding of life history strategies.
2020-12-01T00:00:00ZApplication of genetic techniques to conservation of the Critically Endangered Grenada Dove Leptotila wellsiPeters, Catherinehttp://hdl.handle.net/10034/6275602023-08-16T01:42:47Z2022-09-01T00:00:00ZApplication of genetic techniques to conservation of the Critically Endangered Grenada Dove Leptotila wellsi
Peters, Catherine
The Grenada Dove Leptotila wellsi is a Critically Endangered species endemic to the island of Grenada. It exists in two geographically isolated populations across the island. As an endemic on a small island with a limited and decreasing population, this species is at risk from genetic deterioration. Particular risks include inbreeding depression and accelerated loss of genetic diversity resulting from ongoing habitat fragmentation and population isolation. The work reported in this thesis aimed to provide the first genetic data for the Grenada Dove, assess its genetic status and determine what conservation management recommendations can be made to help ensure its long-term survival. A systematic literature review revealed geographical bias in how genetic approaches have been applied to the conservation of island bird species, under-representation of threatened species and highlighted a gap between genetic research and active conservation management. A protocol for obtaining usable genetic material from moulted plumulaceous feather samples was developed and showed that samples collected non-invasively in the field, that were kept in non-optimal conditions for deoxyribonucleic acid (DNA) extraction, can be used effectively to sequence informative regions of mitochondrial DNA (mtDNA) for genetic analysis. The evolutionary and life history of the Grenada Dove were investigated by estimating its phylogenetic placement and using phylogenetic comparative methods for estimating unknown life history traits. The Grey-Chested Dove Leptotila cassinii was identified as the species with which the Grenada Dove shares the most recent common ancestor, with an estimated divergence of approximately 2.53 million years ago. Life history trait values were predicted for the Grenada Dove and suggest this species will be slow to recover after a major population decline. The mitochondrial genetic diversity of Grenada Dove populations was assessed for the two areas of occupancy. Two haplotypes were identified with one haplotype unique to the population in the West. Selective neutrality tests Fu’s Fs=0.78 and Tajima’s D=0.83 were positive and not significant, with an FST value = 0.71 suggesting a marked genetic divergence between the two populations. This study showed low mitochondrial genetic diversity, a non-expanding population and
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clear evidence for genetically isolated populations. Population viability analysis (PVA) was used to evaluate extinction risk and the potential for conservation management for the two populations of the Grenada Dove. This PVA identified that loss of forest habitat to commercial development is likely to have the biggest impact on extant populations and that conservation management to increase productivity is likely be the most effective conservation strategy. This thesis contributes novel information regarding evolutionary history, life history, population genetics and future population trajectories to inform long-term conservation actions for the Critically Endangered Grenada Dove.
2022-09-01T00:00:00ZThe status of cetaceans in Trinidad and TobagoNaranjit, Alёsha R.http://hdl.handle.net/10034/6272432022-10-20T01:35:36Z2021-12-14T00:00:00ZThe status of cetaceans in Trinidad and Tobago
Naranjit, Alёsha R.
Marine ecosystems provide vital resources for humans and habitat for a vast number of other species. However, these ecosystems are being extensively degraded by human activities, and without effective management, will be unable to provide for humans or other species. In Trinidad and Tobago, as in other countries, one of the major obstacles to effective environmental management is a lack of appropriate information. This thesis aims to enhance the management of cetaceans in Trinidad and Tobago by providing much needed information on cetacean species within the country’s EEZ (Exclusive Economic Zone). Cetacean species diversity and distribution in Trinidad and Tobago is examined through the collation and verification of records from multiple data sources including systematic surveys, reports, skeletal remains, strandings and social media posts. This research provides the first comprehensive overview of the knowledge of cetacean species around Trinidad and Tobago through a verified cetacean species list, estimation of species diversity from local data and maps of species occurrence records. Species Distribution Models were developed for four species (Humpback Whales, Bottlenose Dolphins, Atlantic Spotted Dolphins and Rough-toothed Dolphins) which provide the first estimates of cetacean species distribution across the Trinidad and Tobago EEZ and identify possible cetacean species richness hotspots around the country. Fisher interviews were used to examine the threat posed by artisanal fisheries within the Trinidad and Tobago EEZ and provide the first comprehensive information on cetacean-fisheries interactions for the country. Hunting, depredation (a behaviour in which foraging cetaceans damage or remove catch or bait from fishing gear) and bycatch were all reported in the area. Bycatch was identified as the greatest threat posed by artisanal fisheries locally and analysis indicated that fishing with gillnets or fishing on the south coast of Trinidad with any gear increased the risk of bycatch. The findings of this study were used to recommend actions to improve cetacean management in Trinidad and Tobago, including the creation of a cetacean data management system, the development of a cetacean research programme to guide future research and mitigation of anthropogenic threats on the continental shelf, including cetacean bycatch in artisanal fisheries.
2021-12-14T00:00:00ZAn Examination of the Social and Physiological Experience of Captive Livingstone’s Fruit Bats (Pteropus livingstonii)Edwards, Morgan J.http://hdl.handle.net/10034/6270302022-08-12T01:39:55Z2022-02-01T00:00:00ZAn Examination of the Social and Physiological Experience of Captive Livingstone’s Fruit Bats (Pteropus livingstonii)
Edwards, Morgan J.
This thesis presents a series of empirical studies designed to quantify the complex social and physiological experiences of individuals within the captive population of a critically endangered bat species, the Livingstone’s fruit bat (Pteropus livingstonii). The ultimate goal of this work was to apply leading-edge methodologies and technology to gain novel, evidence-based insights into the behaviour and welfare of this species in captivity. This work has not only informed the captive management of P. livingstonii, but has also developed techniques that can be applied to maximise the captive welfare of a range of other species.
A brief summary, explaining how each chapter is embedded within the overall thesis and summarising its major findings, precedes each chapter. Chapter One, the introductory chapter, will start by evaluating our current understanding of the natural history and behavioural ecology of P. livingstonii, with a focus on captive behaviour. The following sections of this chapter will then provide necessary background information to the methodologies applied in subsequent data chapters, including social network analysis, space use assessment, hormone analysis and radio-frequency identification technology. The introductory chapter is intended to provide the reader with sufficient scientific context to interpret the results of each data chapter.
Chapter Two outlines the implementation of social network analysis to characterise individual social experiences in the largest captive population of P. livingstonii, housed at Jersey Zoo. Variation in network complexity and significant individual variable-based assortment is identified in this chapter. Chapter Three presents principal component analysis as a novel compliment to traditional enclosure use assessment methodologies, quantifying the individual spatial preferences of P. livingstonii. This chapter also quantifies the relationship between high-value resource location within the enclosure at Jersey Zoo and population-level space use. Chapter Four outlines the validation and application of an enzyme immunoassay to non-invasively measure faecal cortisol in the P. livingstonii population. This chapter examines the relationship between cortisol titres, individual social roles and behavioural frequencies performed by individuals in the captive population. We find that males, older individuals and lactating females have higher concentrations of cortisol than non-lactating females and younger individuals and that social roles related to conspecific affiliation were linked to decreased cortisol titres. Lastly, Chapter Five demonstrates the application of unique radio-frequency identification technology to autonomously collect individual locational data. The resulting dataset was then utilised to interrogate the foraging network displayed by P. livingstonii and Pteropus rodricensis (a
cohabitating heterospecific) populations housed at Jersey Zoo, elucidating the relationship between individual bat characteristics and social foraging patterns. Finally, the discussion chapter evaluates the significance of the main findings of each chapter of this thesis, highlighting the wider applicability of results and methodologies to the assessment of captive animal welfare. This section also critically discusses recent challenges to hypothesis testing in the field of animal social network analysis, to evaluate the validity of methods utilised throughout this thesis. Finally, future research directives leading on from this work which may provide further benefit to the management of captive populations are proposed.
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