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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Conflict and cooperation in vertebrate societies

Sanderson, Jennifer Louise January 2012 (has links)
Within animal societies, individuals often differ greatly in their level of investment in cooperative activities. Individuals are predicted to show high cooperative investment if high levels of relatedness lead to large indirect fitness benefits, or if differences in individual characteristics such as age, sex, rank, or body condition increase the direct fitness benefits of helping. However, individual differences often persist after these differences are controlled for; a residual variation that remains unexplained. Understanding the proximate mechanisms underlying variation in behaviour can give novel insights into the selection pressures shaping behavioural differences. This suggests that a research focus onto the proximate mechanisms underpinning cooperative behaviours is needed to further our understanding of why individuals behave differently within social groups. In this thesis, I address this shortfall in understanding by investigating hormonal variation alongside individual differences in cooperative investment in the banded mongoose (Mungos mungo). Banded mongooses are a highly social carnivore with two highly conspicuous forms of cooperative offspring care that are easily measurable and show large inter-individual variation. In chapter 3, I demonstrate a negative carry-over effect of investment in offspring care in consecutive breeding attempts. I show that this carry-over effect is mediated by variation in glucocorticoid concentrations, which may be attributable to the energetic costs of helping. Glucocorticoids predict investment in offspring care, suggesting that this mechanism may drive inter-individual variation in cooperative investment. In chapter 4, I find evidence for a testosterone mediated trade-off between offspring care and mating effort, which suggests that inter-individual differences may also be driven by variation in the costs of helping attributable to missed mating opportunities. In chapter 5, I use simulated territorial intrusions to show that there is unlikely to be a trade-off between offspring care and territory defence in banded mongoose societies. However, carers and non-carers show a differential physiological response to territorial intrusion, suggesting that there may be a more subtle behavioural trade-off that occurs post-intrusion. In chapter 6, I find evidence for consistent individual differences in both cooperative and competitive behaviours, which suggests that individual differences in adult behaviour may be determined by early-life effects. Individual differences in cooperative investment are positively correlated, suggesting that individuals are not specialised to different cooperative activities, but are consistently either helpful or selfish. Together, these results give insights into the selection pressures shaping individual differences and highlight endocrine research as a valuable tool in understanding the evolution of cooperative societies.
2

Screening of banded mongooses (Mungos mungo) for mycobacterial infection in the Kruger National Park, South Africa

Brüns, Angela Caren January 2014 (has links)
Bovine tuberculosis (bTB) was first diagnosed in the Kruger National Park (KNP) in 1990 and research has since focused primarily on the buffalo (Syncerus caffer) as the maintenance host and lion (Panthera leo) as a clinically affected species. However, little is known about the role that small predators might play in the tuberculosis epidemiology. The aim of this pilot study was to screen banded mongoose populations in the bTB high prevalence zone of the KNP for mycobacteria in general and for Mycobacterium bovis and other Mycobacterium tuberculosis complex members in particular to detect presence of infection. Faecal swabs, tracheal swabs and tracheal lavage of 76 banded mongooses caught in cage traps within a two kilometre radius of Skukuza Rest Camp in the KNP were submitted for culture, isolation and speciation of Mycobacterium as the gold standard of bTB diagnosis. Blood was collected and serologically analysed for M. bovis and Mycobacterium tuberculosis antibodies using the ElephantTB STAT-PAK® Assay (STAT-PAK) and the EnferplexTM TB Assay (Enferplex). DPP® VetTB Assay for elephants (DPP) was used on STAT-PAK positive samples. To complement the sample set obtained from live banded mongooses 12 animals were necropsied. Lesions and pooled lymph node samples together with a standard set of organ samples were submitted for culture and histopathology analysis. Two banded mongooses had developed well demarcated, irregularly margined, greyyellow nodules of up to 5 mm diameter located in the caudal lung lobes and/ or tracheo-bronchial, retropharyngeal or superficial cervical lymph nodes. These lesions were characterised by central necrosis in the one and calcification in the other animal. Histopathologically the lesions were described as caseating necrosis associated with epithelioid macrophages and necrogranuloma with calcified centre respectively. No acid fast bacteria were identified with Ziehl-Neelsen stain. M. bovis was isolated from lung, lymph node and liver samples as well as tracheal lavages and tracheal swab from the same two banded mongooses but not from any other study animal. No other Mycobacterium of the M. tuberculosis complex was isolated. However, a variety of environmental mycobacteria, the most frequent from the Mycobacterium avium complex, M. fortuitum group, M. simiae group and M. terrae group, were cultured. M. fortuitum group was only and M. terrae group predominantly isolated from tracheal and faecal samples whereas M. simiae group and M. avium complex were the most frequent species isolated from post mortem samples, including tissue lesions and lymph nodes. Serological analysis revealed 12 banded mongooses with a positive STAT-PAK result, confirmed with DPP. Enferplex was positive for MPB83 in four and MPB70 peptide in one animal. Only two banded mongooses, the ones with the strongest positive reaction on both STAT-PAK and DPP, reacted positively on all three serological assays. These were the same two animals that had developed granulomatous lesions and that M. bovis was cultured from ante and post mortem samples. In conclusion, this study has provided the first evidence of bTB infection in banded mongooses in the KNP and demonstrated their ability to shed M. bovis. This finding has opened the discussion around possible sources of infection and its significance at the human/ wildlife interface in and around Skukuza. / Dissertation (MMedVet)--University of Pretoria, 2014. / tm2015 / Production Animal Studies / MMedVet / Unrestricted
3

Bidirectional interactions between behavior and disease in banded mongooses (Mungos mungo) infected with Mycobacterium mungi

Fairbanks, Bonnie Marie 04 September 2013 (has links)
Behavior and disease interact bidirectionally and on multiple levels of host organization, and these interactions can have important consequences for population-level disease dynamics. I explored how behavior can both influence and respond to infectious disease in a banded mongoose population experiencing epidemics of tuberculosis (TB) caused by the bacterial pathogen Mycobacterium mungi in the M. tuberculosis complex (Alexander et al. 2010). Banded mongooses are highly social carnivores that live in troops of 5 to 65 individuals. Mycobacterium mungi appears to be primarily environmentally transmitted, but direct horizontal transmission cannot be ruled out. Approximately 10-20% of mongooses become diseased with TB each year in the study population in and around Chobe National Park, Botswana, and all mongooses with clinical signs of TB die within months. Characteristics of both banded mongooses and clinical TB provided a productive study system for exploring interactions between behavior and disease: first, free-living mongooses can be habituated and directly observed; second, the clinical signs of TB can be visually assessed non-invasively; and third, the mongooses' high sociality and egalitarianism provide a unique and ecologically relevant host social system for examining bidirectional interactions between behavior and infectious disease. I found that banded mongooses influenced and responded to disease through their behavior at both the individual and troop level, with possible implications for banded mongoose population and disease dynamics. Due to the environmental transmission of M. mungi, which appears to invade mongooses through breaks in the skin and nasal planum (Alexander et al. 2010), I focused on aggressive interactions as a potential risk factor for acquiring TB in this system. Troops with higher levels of aggression had more injuries, and at the individual level, injuries were a strong predictor of TB, suggesting that aggression may increase risk of disease by creating potential invasion sites for the pathogen. Troops were more aggressive when they foraged in garbage than when they foraged in other habitats, presumably due to the concentration of resources at this highly modified habitat. Overall, my results on how behavior can influence disease in this system suggest that anthropogenic supplementation of food, albeit inadvertent in this system, augments aggression levels in banded mongooses and may in turn lead to a higher incidence of TB. Second, I examined how behavior responds to disease in banded mongooses. Diseased individuals showed significantly lower activity and alertness, but intriguingly, did not show a reduction in overall social behaviors. Diseased individuals were less likely to disperse than healthy individuals, and healthy individuals with diseased troopmates may have been more likely to disperse than individuals without diseased troopmates. Despite this latter possible increase in dispersal in the presence of diseased conspecifics, diseased individuals were not avoided by their troopmates in daily social interactions. For example, diseased individuals were allogroomed at a higher than expected rate even though their reciprocation during allogrooming was approximately half that of healthy individuals. These interactions between behavior and disease have implications for banded mongoose troop and population dynamics, via changes in dispersal behavior and mortality, and can also affect disease dynamics, such as transmission rate. For example, changes to dispersal may affect the amount of inbreeding and outbreeding that occurs in this normally inbred species, and disease might be amplified in areas where aggression is increased by resource augmentation from humans. Additionally, the role that garbage plays in mongoose aggression suggests that humans may be inadvertently increasing disease incidence in this system, as well as in other taxa for which anthropogenic food augmentation may alter disease dynamics via changes in intraspecific aggression. This research sheds light on ways that behavior can influence and respond to disease that are often overlooked in disease ecology. / Ph. D.
4

Conflict within and between groups of cooperative banded mongooses

Thompson, Faye Jacqueline January 2016 (has links)
Conflict within and between social groups is a conspicuous feature of cooperative animal societies. Theoretical and empirical research aims to understand the role of within- and between-group conflict in the evolution of cooperative behaviour, but these forms of conflict are rarely studied together. Eviction as a means of within-group conflict resolution can have important implications for the individuals involved, and the wider population through effects on dispersal, gene flow, and population structure. Intergroup conflict, although prevalent in many social species, is relatively understudied outside of humans and chimpanzees, but could play an important role in the evolution of cooperative behaviours. However, currently there is a lack of understanding of the causes and consequences of within- and between-group conflict to be able to draw conclusions on theoretical links to their role in social evolution. In this thesis, I use a wild population of banded mongooses, Mungos mungo, to investigate the causes and consequences of eviction and intergroup conflict in a highly cooperative species. First, I show that eviction in banded mongooses is triggered by reproductive competition in both sexes (Chapter 2). Second, I find that, once the decision to evict has been made, younger females and those older, more closely related females are preferentially evicted (Chapter 3). This surprising result is explained by a theoretical model which shows that, where individuals are capable of resisting eviction, the usual prediction of positive kin discrimination can be reversed. Third, I show that eviction has demographic effects, with consequences for group size and recruitment (Chapter 4). Finally, I show that intergroup conflict is stimulated by intensified resource competition, and that the consequences of intergroup conflict can have measureable costs to both individuals and groups in the long- and short-term (Chapter 5). This work shows that the means of resolving within-group conflict at an individual level can resonate to affect demography and dynamics at higher levels, and that the nature and intensity of intergroup conflict has the potential to influence patterns of cooperation and conflict within groups. I suggest that within- and between-group conflict may often be intimately linked, and that recognising this link could help to advance our conceptual understanding of their role in the evolution of cooperative behaviour.
5

The effect of environmental enrichment on the behaviour of meerkats, banded mongooses and dwarf mongooses in human care.

Berrio Pozo, Alejandro January 2020 (has links)
Animals in captivity can be deprived of performing some of their natural behaviours. Using enrichments may allow them to express a larger part of species-specific behaviour repertoire and with a better frequency distribution. This study focuses on three species of the family Herpestidae which live in captivity at Bioparc Valencia (Spain). The project aims to study the effect of environmental enrichment on the behaviour of meerkats, banded mongooses and dwarf mongooses in human care. To achieve this goal two different types of enrichmentswere tested: (1) a food enrichment with several variations and (2) an olfactory enrichment with the presentation of two new odours. The food enrichment aimed to increase foraging behaviour and the olfactory enrichment aimed to test if captive animals behave differently in the presence of a predator’s odour compared to a non-predator’s odour. Results revealed that foraging can increase up to 16% implementing enrichments and that success depends on the presence and quantity of food. On the other hand, animals did not seem to behave differently in the presence of both odours. The frequencies of behaviours and time spent interacting did not differ between these olfactory enrichments. I conclude that implementing enrichment programmes may ensure better welfare for captive animals.
6

Understanding the Influence of Banded Mongoose (Mungos mungo) Social Structuring on Disease Transmission Using Molecular Tools

Verble, Kelton Mychael 04 February 2019 (has links)
Understanding the disease transmission dynamics in wildlife species can be difficult and can prove more complicated if the population structure of a socially living species is shaped by territoriality. Understanding the connections and movements of individuals between groups is vital to documenting how a disease may be spread. The presence of a heterogeneous landscape can further complicate attempts to describe transmission of an infectious disease. Here, I sought to understand how dispersal patterns of individual banded mongooses (Mungos mungo) could potentially influence disease transmission. Banded mongooses are small fossorial mammals that live in social groups ranging from 5 to 75 individuals and defend their territories against rival troops. The focal population of mongooses for this study lives across a complex environment in the Chobe district of northern Botswana and is faced with a novel strain of tuberculosis, Mycobacterium mungi. To infer genetic structure and individual movements between troops, I utilized microsatellite genetic markers and population genetic analyses. I found moderately strong genetic structuring (FST = 0.086) among 12 troops of banded mongooses in the study area in 2017-18. The best supported number of genetic clusters was K = 7, with a considerable amount of admixture between troops in urban areas. Compared to the average pairwise differentiation values of troops residing in natural habitats (FST = 0.102), urban troops had a lower level of differentiation (FST = 0.081), which suggests more gene flow between these troops. Among 168 mongooses genotyped, 20 were identified as being likely dispersers, with the majority moving across anthropogenic environments, suggesting that dispersal is heightened in urbanized areas. To assess whether temporal variation had an effect on genetic structure and gene flow between troops, I compared population genetic results from 5 troops in 2008 to those from the same 5 troops in 2017. Genetic differentiation was lower between troops living in urban environments than in natural environments for both 2008 and 2017. This result suggests higher gene flow across the anthropogenic landscapes at both times steps. The overall genetic structuring of the troops persisted over almost a decade, with the exception of observing more mixture and admixture in 2017 than in 2008. The effective population sizes (Ne) of troops were larger in 2008, which would indicate that genetic variability declined as time progressed. For 11 individuals confirmed to have M. mungi, an assignment test suggested that 3 mongooses were likely dispersers. This finding would contradict that of previous work, which suggested that sick banded mongooses refrained from dispersing. Sequencing of the M. mungi strains would be needed to determine whether these dispersers moved while sick or became infected after entering their new troop. These findings suggest that emphasis should be placed on closely monitoring banded mongoose troops in areas with heavy human influence. Here we see lower pairwise differentiation, higher gene flow estimates, and more frequent dispersal events. Heightened dispersal potentially can result in elevated disease transmission between troops in urban habitats. With disease transmission being the result of complex interactions between environment, host, pathogen, and time, results from this study contribute to understanding of disease transmission dynamics. / MS / Understanding how groups of the same species are connected is important for assessing how wildlife diseases spread across a landscape. For social species, connections are established by the movements of individuals between different groups; however, these can prove difficult to observe. Further complicating our ability to infer connections and movements, groups often live under different environmental conditions, which can influence movement rates. I studied banded mongooses (Mungos mungo) living in northern Botswana to assess the role of individual movement on the potential for disease transmission. Banded mongooses are small ground-dwelling mammals that live in troops of 5-75 individuals and defend group home-ranges. In Botswana, some troops are infected with a species of tuberculosis (TB, caused by the bacterium Mycobacterium mungi) that is unique to banded mongooses. Using molecular genetic tools, I estimated how genetically similar troops were to one other and estimated the rates of movement of individuals between troops. I found that troops living in urban environments tended to be more genetically similar to one other compared to troops living in natural environments within nearby Chobe National Park. I also detected more cases of individuals moving between troops in urban settings, with little evidence of movement between troops living in natural areas. These results suggest that there is more genetic exchange and a higher degree of connection between troops living in areas heavily influenced by people. With more connections between town-dwelling troops, we would expect to see higher rates of disease transmission between these urban troops, and hence should monitor their movement and health status closely. I also assessed how genetic structure and connections between banded mongoose troops changed over time by comparing results for collections of samples made in 2008 and 2017. Although more movement was detected in 2017, the overall pattern of genetic connections remained similar over the ten-year period. In particular, there was greater genetic similarity between troops in town compared to troops in natural environments in both years. Additionally, I genetically assigned TB-positive individual mongooses to their troop of origin to determine whether sick individuals moved out of their original troops. I identified three sick individuals as probable dispersers, although it is difficult with the information available to know whether they moved while infected or became ill after joining a new troop.
7

Developing Transcriptional Markers for Detecting Infection with the Novel Tuberculosis Pathogen, Mycobacterium mungi, in Free-Ranging Banded Mongoose (Mungos mungo)

Sybertz, Nicholas Michael 20 January 2022 (has links)
Effectively developing robust predictive models for forecasting infectious disease dynamics over space and time relies on successful surveillance strategies to accurately assess host infection status. We are constantly refining these models to improve our understanding of transmission and persistence dynamics in host populations but are continuously challenged with difficulties in accurately diagnosing host infection status. These challenges are especially persistent for pathogens of the Mycobacterium tuberculosis Complex (MTBC), which cause tuberculosis (TB) disease in a wide array of mammalian hosts. These challenges are further exacerbated when working with MTBC pathogens in free-ranging wildlife hosts. Although TB disease in humans is a primary concern, TB in free-ranging wildlife hosts poses a large threat to human and animal health. One recently described and novel MTBC pathogen is Mycobacterium mungi, which infects the highly social, group-living banded mongoose (Mungos mungo). M. mungi poses a large threat to human and animal health as banded mongoose hosts thrive in urbanized areas and live in close proximity to humans, but despite this threat, accurately diagnosing M. mungi infection status remains a primary challenge. Here, I develop a host response-based assay for differentiating banded mongoose with clinical M. mungi disease from individuals that are putatively healthy using transcriptional biomarkers in whole blood. To our knowledge, this is the first evaluation of host response-based transcriptional signatures to detect TB infection in unstimulated whole blood collected from a free-ranging wildlife species. I found that the expression of two genes, GBP5 and DUSP3, are significantly upregulated (GBP5, p < .05; DUSP3, p < .005) in banded mongoose with clinical M. mungi disease when compared to that of putatively healthy individuals. These results are consistent with studies of active M. tuberculosis disease in humans and support the use of host response-based assays using blood transcriptional biomarkers for diagnosing TB in free-ranging wildlife hosts. These findings are important for improving surveillance strategies for diagnosing M. mungi infection status in banded mongoose and will be essential in refining predictive models for forecasting transmission and persistence dynamics over space and time. / Creating models to predict how diseases circulate and persist within a population is dependent on our ability to accurately diagnose if a host is infected. Diagnosing infection is difficult for some diseases, including tuberculosis (TB) pathogens, which infect humans and many other mammalian species. While vast improvements have been made in diagnosing TB infection in humans, diagnosing TB in free-ranging wildlife species is a constant challenge. These challenges are further exacerbated across the different pathogen species of TB. Although TB disease in humans is a primary concern, TB in free-ranging wildlife hosts poses a large threat to human and animal health. One recently discovered TB pathogen is Mycobacterium mungi, which infects free-ranging banded mongoose (Mungos mungo). This pathogen poses a large threat to human and animals health since banded mongoose thrive in urbanized areas and live in close proximity to humans. Despite this threat, accurately diagnosing M. mungi infection in banded mongoose remains a challenge. Here, I develop a diagnostic molecular tool that uses banded mongoose blood to measure the expression of specific genes and differentiate diseased individuals from seemingly healthy individuals. To our knowledge, this is the first study that has used this specific approach for diagnosing TB in a free-ranging wildlife species. I found that the expression of two genes are significantly increased in banded mongoose with clinical M. mungi disease when compared to that of seemingly healthy individuals. These results are consistent with studies human TB disease in humans and support the use of this approach for diagnosing TB in free-ranging wildlife hosts. These findings are important for improving diagnostics for M. mungi infection in banded mongoose and will be essential in refining models for predicting how this disease circulates and persists over space and time.

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