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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.
11

Conservation and management of populations in a fragmented forest landscape:behavioural ecology meets population genetics

Mäki-Petäys, H. (Hannaleena) 06 February 2007 (has links)
Abstract The effects of habitat loss and fragmentation on the genetic structure and vulnerability of populations strongly depend on the behaviour of a particular species. In this thesis, I examined the effects of forest fragmentation on genetic population structure with the aim of identifying and evaluating the different genetic and behavioural factors important for species conservation and management on different geographical scales. The species studied were the mound building red wood ants Formica lugubris and F. aquilonia, and a lekking bird, the capercaillie, Tetrao urogallus. Habitat loss and fragmentation affected the genetic structure in both wood ants and capercaillie. In general, the effects were related to the time since fragmentation and to the level of habitat loss and isolation from the other existing populations. The loss of genetic diversity due to population fragmentation was less observable than the differences in population structure. The response to habitat fragmentation was further dependent on species characteristics such as dispersal and mating behaviour. Sociality affected the genetic vulnerability of wood ant populations by decreasing gene diversity, increasing inbreeding depression and restricting gene flow between subpopulations. The results on the capercaillie in turn suggested that lekking behaviour restricts dispersal of both sexes, thus elevating the occurrence of inbreeding between individuals. The present study provided important information on species conservation and management in terms of better understanding species' biology and behaviour, as well as increased knowledge concerning the genetic issues that should be taken into account when planning conservation actions. By examining the genetic structure of the species it was possible to clarify the conservation status including the effective population size, the question of origin, and the genetic vulnerability (genetic diversity, inbreeding and inbreeding depression) of the populations and/or species. Overall, the results emphasised the importance of preserving the effective population size and the connectivity of habitat patches when planning species specific management strategies. There were great differences in conservation needs among the species, which should be taken into account especially in local management actions.
12

Phylogenetic and Ecological Significance in the Evolution of Cetacean Tonal Sounds

May-Collado, Laura Johanna 05 November 2007 (has links)
Cetaceans are aquatic mammals that rely primarily on sound for most daily tasks. A compendium of sounds is emitted for orientation, prey detection, and predator avoidance, and to communicate. Communicative sounds are among the most studied Cetacean signals, particularly those referred to as tonal sounds. Because tonal sounds have been studied especially well in social dolphins, it has been assumed these sounds evolved as a social adaptation. However, whistles have been reported in ‘solitary’ species and have been secondarily lost three times in social lineages. Clearly, therefore, it is necessary to examine closely the association, if any, between whistles and sociality instead of merely assuming it. Several hypotheses have been proposed to explain the evolutionary history of Cetacean tonal sounds. The main goal of this dissertation is to cast light on the evolutionary history of tonal sounds by testing these hypotheses by combining comparative phylogenetic and field methods. This dissertation provides the first species-level phylogeny of Cetacea and phylogenetic tests of evolutionary hypotheses of cetacean communicative signals. Tonal sounds evolution is complex in that has likely been shaped by a combination of factors that may influence different aspects of their acoustical structure. At the inter-specific level, these results suggest that only tonal sound minimum frequency is constrained by body size. Group size also influences tonal sound minimum frequency. Species that live in large groups tend to produce higher frequency tonal sounds. The evolutionary history of tonal sounds and sociality may be intertwined, but in a complex manner rejecting simplistic views such as the hypothesis that tonal sounds evolved ‘for’ social communication in dolphins. Levels of social and tonal sound complexity nevertheless correlate indicating the importance of tonal sounds in social communication. At the intraspecific level, tonal sound variation in frequency and temporal parameters may be product of genetic isolation and local levels of underwater noise. This dissertation provides one of the first insights into the evolution of Cetacean tonal sounds in a phylogenetic context, and points out key species where future studies would be valuable to enrich our understanding of other factors also playing a role in tonal sound evolution.
13

Environmental Impacts on Behavior and Personality in the Caviomorph Rodent, Octodon degus

Johnson, Nicholas Edwin January 2019 (has links)
Environmental factors can have large impacts in shaping the way that animals behave. Biotic elements, such as predators and conspecifics that individuals interact with, are two environmental factors that animals may encounter on a regular basis. Here, we present the results of two studies examining the relationship of these biotic factors to behavior and personality in the degu (Octodon degus), a social rodent species endemic to central Chile. We found that long-term experimental isolation from predators has not impacted behavior, as indicated by an open field test in this species. We also found that social groups in this species do not adhere to either conformity or social niche specialization expectations with regard to personality, as determined in open field tests. These results raise further questions as to the mechanisms that govern behavior, as well as how personality evolved and is maintained in natural populations.
14

The Socioecology, Mating System and Behavior of Round-Tailed Ground Squirrels (Xerospermophilus tereticaudus)

Munroe, Karen Elizabeth January 2011 (has links)
Social organization of a species may impact behavior, reproductive ecology, mating system, population genetic structure and overall fitness. A spectrum of sociality exists from solitary individuals to aggregations to integrated, highly related groups. A large body of knowledge exists for sociality and life-history characteristics of ground-dwelling sciurids, including several overarching models to explain the evolution of sociality. These models predict round-tailed ground squirrels (Xerospermophilus tereticaudus) to be solitary based on small body size (~125g), relatively long period of activity (January-June) and a short period of adult-juvenile overlap. However, previous behavioral observations suggest round-tailed ground squirrels have a clustered matrilineal structure with a suite of social behaviors, suggesting that they may represent a unique outlier in ground squirrel sociality models. Within the population of round-tailed ground squirrels at the Casa Grande Ruins National Monument in Coolidge, Arizona, USA, rates of amicable and agonistic interactions between adults were low, with no relationship between relatedness of individuals and rates of social interactions. No population substructure was evident with Bayesian analyses, global or pairwise F(ST) values, and average relatedness among females did not differ from males. Contrary to previous behavioral studies, round-tailed ground squirrels did not have high levels of social behavior, nor did they form significant genetic subpopulation structuring. The active season of round-tailed ground squirrels closely followed patterns of precipitation and peak resource availability. Body mass differed between males and females, across years, and within seasons. Males were heavier than females at emergence, prior to mating and pre-hibernation, but not when females began gestation. Emergence of litters and litter size are related to amount and timing of winter rainfall. Foraging and vigilance behaviors compose 64-66% of the activity budget, but differ in that males spend a greater proportion of time foraging, whereas females spend a greater proportion of time vigilant. Round-tailed ground-squirrels have a polygynandrous mating system. Polygyny was evident in 2004, 2005, and 2006, and multiple paternity occurred in the majority of litters with 2.5 sires/litter; litter size was positively correlated with the number of sires. These findings support predictions generated by sociality models for ground-dwelling squirrels.
15

Un-common Sociality : Thinking Sociality with Levinas

Rat, Ramona January 2016 (has links)
The present investigation develops the notion of sociality based on Emmanuel Levinas’s thought, and proposes an understanding of sociality that resists becoming a common foundation: an un-common sociality which interrupts the reciprocal shared common, and thereby, paradoxically, makes it possible. By engaging in the larger debate on community, this work gives voice to Levinas on the question of community without a common ground, a topic and a debate where he has previously been underestimated. In this way, the aim is to reveal new directions opened up by Levinas’s philosophy in order to think an un-common sociality.
16

Insetos sociais e a estrutura de redes de polinização / Social insects and the structure of pollination networks

Maia, Kate Pereira 25 July 2014 (has links)
Mutualismos entre plantas e polinizadores estão organizados em redes de interação que envolvem muitas espécies. Em última instância, o que determina a ocorrência das interações entre plantas e polinizadores são as características dos dois grupos de espécies. O comportamento social pode ser uma das caraterísticas chave na organização das interações em sistemas de polinização. Investigamos se a presença de polinizadores com comportamento social em redes de polinização está associada a diferentes padrões estruturais, e se polinizadores com níveis crescentes de complexidade no comportamento social são mais importantes pra estrutura dessas redes. Encontramos que a variação na proporção de espécies sociais não altera a estrutura de redes de polinização. Encontramos também que espécies com comportamento social são, em média, mais importantes para a estrutura de redes de polinização do que espécies solitárias. Nossos resultados corroboram resultados anteriores que sugerem que redes mutualísticas tem estruturas invariantes. Nossos resultados sugerem ainda que o papel estrutural mais proeminente das espécies sociais está associado à sua maior abundância. Incluir aspectos da história natural das espécies e das interações em estudos de redes ecológicas, nos permitirá fazer inferências cada vez mais assertivas sobre a importância funcional das espécies em comunidades / Mutualisms between plants and pollinators are organized in interaction networks that involve many species. Ultimately, what determines the occurrence of interactions among plants and pollinators are the traits of both groups of species. Social behavior can be a key trait on the organization of interactions between plants and pollinators. Here, we investigated if the presence of pollinators with social behavior in pollination networks is associated to different structural patterns, and if pollinators with increasing levels of complexity in social behavior are more important for network structure. We found that the presence of social pollinator species does not affect the structure of pollination networks. We also found that species with social behavior are, on average, more important for network structure than solitary species. Our results reinforce past studies that suggested that the structure of mutualistic networks has invariant structural properties. Our results also suggest that the more prominent role occupied by pollinators with social behavior is associated to these species\' large abundances. Including natural history information about species and about species interactions on the study of ecological networks will allow us to make more assertive inferences on the functional roles species occupy in ecological communities
17

Memória e socialidade: como o reconhecimento individual afeta formação de grupos / Memory and sociality: how individual recognition affects group formation

Rios, Vitor Passos 29 July 2016 (has links)
Nesta tese, nós investigamos os efeitos do reconhecimento individual sobre a formação de grupos. No capítulo 2 nós revisamos o conhecimento sobre as bases evolutivas do comportamento social, e no capítulo 3 nós nos focamos num mecanismo específico, o reconhecimento individual. Nós revisamos as bases do reconhecimento individual para construir um modelo mínimo de como o reconhecimento individual funciona, visando investigar suas consequências para a estrutura social dos animais. O capítulo 4 é construído como uma introdução à modelagem computacional. Utilizando a técnica de modelagem baseada em agentes, no capítulo 5 nós criamos uma população de indivíduos que são capazes de reconhecer uns aos outros e de lembrar as interações passadas. Nós demonstramos que a presença de memória e reconhecimento individual é capaz de afetar dramaticamente o número e tamanho dos grupos formados. Quando não há memória, os indivíduos formam muitos grupos pequenos, sem estrutura definida. Na presença de memória, os indivíduos se agrupam em clusters cerca de uma ordem de grandeza maiores, e consequentemente menos grupos são formados. Nós demonstramos também que a organização interna dos grupos muda: na presença de memória, os grupos apresentam modularidade maior, isto é, há formação de subgrupos dentro do cluster, onde há uma maior frequência de interações entre os indivíduos. Nossos resultados também mostram a influência da densidade para a formação de grupos: quando a densidade é baixa demais, mesmo na presença de reconhecimento individual, as probabilidades de encontro são baixas demais para que os efeitos do reconhecimento sejam percebidos, e o inverso ocorre com densidades altas demais / In this thesis, we investigate the effects of individual recognition on group formation. In chapter 2 we review the current knowledge on the evolutionary basis of social behavior, and in chapter 3 we focus on a specific mechanism, individual recognition. We review the basis of individual recognition to devise a minimal model of how individual recognition works, aiming to investigate its consequences on the social structure of animals. Chapter 4 is structured as an introduction to computational modelling. Using agent-based modelling, in chapter 5 we build a population of individuals which can recognize one another and can remember past interactions. We show that presence of memory and individual recognition can dramatically affect the number and size of groups in the absence of memory, individuals form small, unstructured groups. In the presence of memory, individuals form clusters about an order of magnitude greater in size, and consequently less groups are formed. We also show that the group\'s internal structure changes: with memory, group modularity is higher, that is, subgroups are formed within the cluster, in which frequency of interactions is greater than outside the subgroup. Our results also show that density affects group formation: when density is low, even with individual recognition, encounter probabilities are so low that recognition\'s effects are not visible, and the opposite holds for too high densities
18

Pragmatism, knowledge production and democratic renewal : the E14 Expedition

Harney, Liam January 2017 (has links)
Western democracies are characterised by a significant level of distrust and widespread feelings of disenfranchisement amongst ordinary citizens. The rise of populist political parties, figures and movements reflects the gradual development of a strong and increasingly vocal anti-establishment sentiment amongst millions of people who feel that the ideas and actions of political elites and experts are at odds with and do not represent their own lives. As sites where political elites are educated and socialised, universities (and the knowledge they produce) have a role in both causing and potentially solving this democratic deficit. There is a role for universities to alter their epistemological practices in ways that respect and give voice to the multiplicity of experiences, beliefs and issues in the world. There is also scope for universities to engage in civic education both on and off campus. This thesis reflects on an experiment that attempted to do this, applying the principles of philosophical pragmatism and the democratic vision of John Dewey in a participatory research project in east London to convene publics of citizens around pressing social issues and develop their power to effect change. This experiment highlighted the importance of having an underlying, place-based, civic infrastructure comprising relationships and sociality to do this work. There were further challenges in adequately respecting pluralism in a diverse world, and building citizen power in a context where experts are deemed to know best. The thesis ends by examining the wider lessons of this experiment. It looks at the potential of community-university partnerships to act as vehicles for democratic renewal, arguing that universities have the potential to re-cast themselves as mediating institutions to facilitate democracy in their local communities.
19

Causes and Consequences of Fission-Fusion Dynamics in Female Northern Long-Eared Bats, Myotis septentrionalis

Patriquin, Krista 23 May 2012 (has links)
Individual costs and benefits of living in groups vary with group size, stability, and composition. Investigations of these features of group living have lead to the recognition of a variety of social structures. Although many studies have examined social structure in animals with long-term, stable groups, little is known about groups with highly variable group size and composition, such as fission-fusion dynamics. In this thesis I examined the causes and consequences of fission-fusion dynamics by exploring the socioecology of female northern long-eared bats, Myotis septentrionalis. Like many temperate bats, female northern long-eared bats show natal philopatry to summer areas. During this time, they live in groups with fission-fusion dynamics as individuals move among a network of roosts and roost-groups. To examine the causes of fission-fusion dynamics, I examined why females switch roosts. To address the consequences of these dynamics, I asked whether females could form stable relationships, and what factors might explain these relationships. I was able to identify the possible causes and consequences of fission-fusion dynamics that had not yet been explored in bats. I demonstrated that fission-fusion dynamics may be explained, at least in part, by changes in ambient conditions that prompt frequent roost-switching. Despite the highly dynamic nature of these groups, females formed long-term social relationships that were based in part on age and genetic relatedness. These findings have potential consequences for the evolution of social behaviour within groups, such as cooperation and nepotism. My work also raised several questions that require further examination to fully understand the evolution of fission-fusion dynamics. For example, the question remains whether species or sympatric groups of conspecifics with different degrees of roost-switching show the same social structure. By answering these questions, we can gain a better understanding of the causes and consequences of fission-fusion dynamics across species of bats. Once this is achieved, we can then look for parallels with other taxa to answer questions about the evolution of these dynamic systems.
20

Patrões, fregueses e donos : economia e xamanismo no médio rio Negro

Nascimento, Luiz Augusto Sousa do 07 March 2017 (has links)
Submitted by Aelson Maciera (aelsoncm@terra.com.br) on 2017-08-30T19:29:29Z No. of bitstreams: 1 TeseLASN.pdf: 4078819 bytes, checksum: ab142a4a31e104342d51191d07573a62 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-09-25T17:38:30Z (GMT) No. of bitstreams: 1 TeseLASN.pdf: 4078819 bytes, checksum: ab142a4a31e104342d51191d07573a62 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-09-25T17:38:38Z (GMT) No. of bitstreams: 1 TeseLASN.pdf: 4078819 bytes, checksum: ab142a4a31e104342d51191d07573a62 (MD5) / Made available in DSpace on 2017-09-25T17:59:57Z (GMT). No. of bitstreams: 1 TeseLASN.pdf: 4078819 bytes, checksum: ab142a4a31e104342d51191d07573a62 (MD5) Previous issue date: 2017-03-07 / Não recebi financiamento / The thesis is the result of an ethnographic research in the Middle Rio Negro region of the Amazonian northwest. This region is inhabited by multiethnic populations (Arawak, Eastern Tukano and Yanomami), predominantly for the baré group, which participates in a broad process of sociality with multiple agents, both human and nonhuman. It is tried to present the perspective of the Baré as to the economic system of which they participate, considering this wide range of relations. From the narratives and reports from daily life, I address issues such as the occupation of the present territory, the constitution of communities, work on the extraction of piaçaba and its link with other worlds and their owners. From the baré point of view, I try to elaborate an anthropological reflection about the main gears of the economic system in which they participate - the regime de aviamento, in which patrons and customers connect in symmetrical and asymmetric relations. In this context, I discuss the encounters between humans and non-humans in different social spaces: the river, the forest and the community. The meetings in these spaces are a complex and complex system that includes patrons, patrons, owners, recipients, prayers, shamans, enchants, and whose synthesis can be taken from a baré story: "Together and mixed are true peoples, inhabitants of the forest and Rivers ". / A tese é o resultado de uma pesquisa etnográfica no Médio Rio Negro, na região do noroeste amazônico. Essa região é habitada por populações multiétnicas (Arawak, Tukano Oriental e Yanomami), com predominância para o grupo baré, que participa de um amplo processo de socialidade com múltiplos agentes, humanos e não-humanos. Procura-se apresentar a perspectiva dos Baré quanto ao sistema econômico de que participam, considerando esse amplo leque de relações. A partir das narrativas e de relatos oriundos na vida diária, abordo questões como a ocupação do território atual, , a constituição das comunidades, o trabalho no extrativismo da piaçaba e seu vínculo com outros mundos e seus donos. Desde o ponto de vista baré procuro elaborar uma reflexão antropológica acerca das principais engrenagens do sistema econômico do qual eles participam – o regime do aviamento, no qual patrões e fregueses se conectam em relações simétricas e assimétricas. Nesse contexto, discuto os encontros entre humanos e não humanos em diferentes espaços de socialidade: o rio, a floresta e a comunidade. Os encontros nesses espaços configuram um emaranhado e complexo sistema que inclui patrões, fregueses, donos, benzedores, rezadores, xamãs, encantes, e cuja síntese pode ser retirada de um relato baré: “juntos e misturados somos povos verdadeiros, habitantes da floresta e dos rios”.

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