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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

Techniques to assist conservation breeding of the babirusa (Babyrousa celebensis)

Ogle, Sharron January 2010 (has links)
With the current rate of loss of biological diversity worldwide estimated at 100- 1000x the natural background rate, solutions are urgently needed to avoid a catastrophic and irreversible loss of species. Conservation breeding is a tool now widely used to assist in maintaining populations in a safe environment until such time as they can be released back into their natural habitat. The babirusa (Babyrousa celebensis) is a threatened species for which conservation breeding is an integral part of its conservation management. Native to a few Indonesian islands, the babirusa is under threat from habitat destruction and hunting and is estimated to have a wild population of only a few thousand. Conservation breeding was established in 1972 with the translocation of animals from Sulawesi to the Surabaya Zoo in Java, Indonesia. It is thought that 1.2 animals founded what is now a worldwide ex-situ population of around 200 individuals. With concerns mounting regarding likely levels of inbreeding and reduced reproductive success, particularly within the European population, this thesis aimed to utilise a number of techniques to assist the conservation breeding programme. Extensive studbook analysis was used to assess typical reproductive parameters for the babirusa in a captive setting; genetic analysis using microsatellite and mitochondrial DNA markers was used to clarify some aspects of the studbook and to estimate the level of variation within and between populations in different geographical areas; and faecal steroid analysis has been used to shed light on the physiological processes underpinning female reproduction. The combined output from these studies has added to our knowledge of this species and its performance in an ex-situ setting, and has now been used to inform future management of the conservation breeding programme.
2

Efeito fundador em populações de cativeiro: o caso do urso de óculos (Tremarctos ornatus Cuvier, 1825) e seu significado para o manejo e futura conservação ex situ

Corrêa, Mariana Coletto 14 August 2014 (has links)
Made available in DSpace on 2016-06-02T19:32:14Z (GMT). No. of bitstreams: 1 6527.pdf: 2310287 bytes, checksum: 6b506abf65a5fa7b4ec9bb3b44d34a22 (MD5) Previous issue date: 2014-08-14 / Financiadora de Estudos e Projetos / Species kept in captivity are of great importance for in situ conservation of natural populations. In order to fulfill this role, they need to be properly managed with the aim to avoid the consequences of a captive environment, such as: loss of genetic diversity, inbreeding depression, accumulation of deleterious alleles and genetic adaptation to captivity (the first three due to the small number of breeding stock). Thus, with the aim to test founder effects in captive ―populations‖, we used as study model the spectacled bears from Brazilian zoos. This ―population‖ consists of twenty-one bears found in eight zoos along the country, which are originated from just twelve founding individuals. To test a possible founder effect, we analyzed twelve heterologous microsatellite loci for all the specimens of the species in Brazil. Results for the number of alleles and allelic richness obtained through the rarefaction method showed that spectacled bears in captivity have reduced levels of allelic richness in relation to three natural populations (Colombia, Ecuador and Venezuela) studied by other authors; suggesting that bears from Brazilian zoos suffered the consequences of a founding effect, as they have only a fraction of the gene pool of the ancestral population. From the information present in the studbook was possible to verify that there are two families of spectacled bears, and according to the individuals´s multilocus genotypes, we found alleles that are present in a same family and absent in the other. Regarding the kinship, there was a discrepancy in the results with the molecular estimators through the softwares ML-Relate and Coancestry and the information given by the institutions. The information obtained in this work are fundamental to the ex situ conservation program in Brazil with the objective of maintain as high as possible the genetic diversity for future reintroduction plans of the species in nature. / Espécies mantidas em cativeiro são de grande importância na conservação in situ de populações naturais. A fim de que possam desempenhar este papel é necessário que sejam devidamente manejadas, para que as consequências que o cativeiro traz sejam evitadas, como por exemplo: perda de diversidade genética, depressão endogâmica, acúmulo de alelos deletérios e adaptação genética ao cativeiro (as três primeiras devido ao pequeno número de espécimes dos plantéis). No Brasil, uma espécie de mamífero que vem sendo criada em cativeiro desde 1970 e que passou por um efeito fundador, é o urso de óculos (Tremarctos ornatus). O plantel existente hoje totaliza o número de vinte e um ursos, encontrados em oito zoológicos do país, o qual se originou de apenas doze indivíduos fundadores. Para avaliar as consequências de um conhecido efeito fundador, analisamos doze locos heterólogos de microssatélites para todos os exemplares da espécie nos zoos do país, através de amostragem não-invasiva. Resultados referentes ao número de alelos e à riqueza alélica obtida por meio do método de rarefação mostraram que os ursos de óculos de cativeiro possuem valores reduzidos de riqueza alélica em relação a três populações naturais (Colômbia, Equador e Venezuela) estudadas por outros autores; sugerindo que os ursos dos zoológicos brasileiros sofreram as consequências de um efeito fundador, pois possuem apenas uma fração do pool gênico da população ancestral. A partir das informações presentes no studbook foi possível verificar que existem duas famílias de ursos de óculos, e de acordo com os genótipos multilocos dos indivíduos, encontramos alelos que estão presentes em uma mesma família e ausentes na outra. Em relação ao parentesco, houve uma discrepância nos resultados encontrados com os estimadores moleculares através dos softwares ML-Relate e Coancestry e o histórico cedido pelas instituições. As informações obtidas em nosso trabalho, portanto, são fundamentais para que os ursos encontrados nos zoológicos do Brasil possam participar na formação de casais em futuros programas de reprodução ex situ com o propósito de serem utilizados em planos de reintrodução da espécie na natureza.

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