Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 77 for “"breeding success"”.
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Immunocompetence, testosterone and breeding success in red bishop (Euplectes orix)
… centred around trade-offs between reproductive success and health in adult and nestling red bishops (Euplectes orix). The studies employ multiple methods to assess general health (e.g. body condition index, white blood cell count) and immune responsiveness (phytohaemagglutinin skin swelling …
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Factors impacting the breeding success of African penguins Spheniscus demersus on Robben Island
… coast of Africa and can be found in three main breeding localities; southern Namibia, the Western Cape and Algoa Bay, Eastern Cape, South Africa. The African penguin has been listed as Endangered since 2010, having experienced a decline in population of more than 50% over the past three …
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The population status, breeding success and foraging ecology of Phoebetria albatrosses on Marion Island
Seabird populations breeding within the Southern Ocean have experienced various threats over the past few decades. Albatrosses are particularly at risk due to several factors, inter alia, accidental bycatch on fishing gear, ingestion of polluted marine debris, invasive predatory species at breeding …
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Changes in nesting numbers and breeding success of African White-backed Vultures in northern Botswana
… information on their population trends or their breeding success in this country. However, in recent years within Botswana and neighbouring countries there have been multiple incidents of mass poisonings, which have resulted in the deaths of thousands of White-backed Vultures. I therefore …
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The influence of investigator disturbance on aggressive behaviour and breeding success of ring-billed gulls (Larus delawarensis) /
… disturbance on aggressive behaviour and breeding success of individual pairs of ring-billed gulls nesting at two colonies near Port Colborne, Ontario. The insular colony was on an artificial breakwall, associated with the Welland Ship Canal, approximately 1 km off the north shore of Lake …
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The influence of vulture restaurants on breeding success and nestling body condition of Gyps vulture populations across southern Africa
… condition (African White-backed Vultures) and breeding success (Cape Vultures/African White-backed Vultures) in relation to a variety of variables which described levels of access to vulture restaurants. My data suggest the potential of vulture restaurants to increase breeding success in …
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The population status, breeding success and diet of Subantarctic Skuas two decades after the feral cat eradication on Marion Island
… behind predator population trends, diet and breeding success. Changes in predator abundance and breeding success represent numerical responses to changes in prey abundance, whereas dietary shifts can be classified as functional responses. Invasive mammals introduced to island ecosystems can …
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Breeding success, prey use, and mark-resight estimation of burrowing owls nesting on black-tailed prairie dog towns: plague affects a non-susceptible raptor
… examined effects on prey use, nest density, and breeding success, and used mark-resight methods for owl population estimation. Prairie dogs experience high mortality from plague, and their colonies are periodically extirpated by outbreaks. Plague does not make owls sick, but they may be affected …
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Reproduction of coastal birds breeding in the Wadden Sea: variation, influencing factors and monitoring
The study was aimed to determine breeding success including its variability of coastal birds breeding in the Wadden Sea. A further aim was to assess the contribution of current breeding success to population trends of single species. The studies were conducted during the mid 1990s and at the …
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Impacts of the introduced house mouse on the seabirds of Gough Island
… Petrel chicks in 2004. Crude estimates of annual breeding success were 47%, 7% and 7% in 2003, 2004 and 2006, respectively. Mouse attacks were responsible for most chick failures. Mice were largely responsible for high numbers of Tristan Albatross chick failures in 2004-2006. Total failures were …
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Captive breeding programmes for nocturnal prosimians
… sort to determine if husbandry methods affect breeding success. This involved conducting a survey of the current husbandry methods used in 20 European zoos. Statistical tests were carried out to determine if there was a correlation between institution breeding success and the husbandry methods …
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The effects of human disturbance and climatic conditions on breeding Cassin’s auklets
… effects of adverse climatological conditions on breeding success of this species. First, using some biometrics of the individuals captured, I tested a method for aging Cassin’s auklet based on the iris colour. My results corroborate what was proposed before, juveniles have a dark-brown iris that …
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Senescencia, parasitismo, inmunidad y éxito reproductor en el Avión Común (Delichon urbica Linneo 1758)
Breeding success of birds is affected by blood parasites infections, by influencing clutch size, or by producing an energetic cost in inmune response. Infection increases as a consecuence of inmunological deterioration with age. Yolk androgen allocation depends on female body condition.
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Survival and reproduction in a biennially-breeding seabird : the Wandering Albatross
… Marion Island to investigate adult survival, breeding biology and factors affecting reproductive success of this long-lived pelagic seabird. Until recently, the complex adult life cycle has caused biases in conventional mark-recapture modelling analyses that assume that recapture probability …
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Handling the heat: managing microclimates for nesting desert hornbills
… globally, including via negative impacts on breeding success. For example, over the last decade, rising temperatures in the Kalahari Desert, South Africa, have caused serious declines in the breeding success of Southern Yellow-Billed Hornbills Tockus leucomelas. Previous research suggests the …
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Influence of ecosystem variability on the demography and reproductive performance of two Eudyptes penguins, Macaroni and Eastern Rockhopper Penguins, at sub-Antarctic Marion Island, 1994–2019
… The aim of my thesis is to update trends in the breeding populations of Macaroni and Eastern Rockhopper Penguins at Marion Island from 1994–2019. The breeding population of Macaroni Penguins has decreased more or less consistently at an average rate of 1.9% per year since 1994, whereas Eastern …
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The endangered bank cormorant Phalacrocorax neglectus: the heat is on : understanding the effect of climate change and associated environmental variable changes on the breeding biology and population dynamics of the bank cormorant in the W. C., S. A
… involved research on the heat stress behaviour, breeding success and population trends of the bank cormorant in the Western Cape, South Africa. High environmental temperatures resulting in heat stress and storms with associated extreme environmental variables was predicted to cause breeding …
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The ecstatic display call of the Adélie penguin (Pygoscelis adeliae)
… call. Additionally, the effects of an inclement breeding season on factors that affect breeding success will be examined using a logistic regression approach. The study took place over two breeding seasons(2000/1 & 2002/3) on Ross Island, Antarctica, with the majority of research being conducted …
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The role of supplementary feeding sites in vulture conservation in South Africa
… through enhancing demographic parameters such as breeding success and survival. While there is some evidence for such effects, more recent critical assessments are questioning assumptions that these effects are ubiquitous. Additionally, research has begun to identify unintended negative …
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Comparative breeding biology of the Northern Rockhopper penguin Eudyptes moseleyi on Gough and Nightingale Islands
… Endangered due to an estimated 57% decrease in breeding numbers over the past 37 years. Approximately 85% of the global population breeds at the Tristan da Cunha archipelago (Tristan, Inaccessible and Nightingale Islands) and nearby Gough Island in the central South Atlantic Ocean. The …
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