Bumblebees have undergone dramatic declines both in Britain and further afield during the last century. Bumblebees provide a crucial pollination service to both crops and wild flowers. For these reasons, they have received a great deal of research attention over the years. However, the ecology of wild bumblebee nests and the interactions between nests and other species, particularly vertebrates has been somewhat understudied. This is largely due to the difficulty in finding sufficient nests for well replicated study and a lack of appropriate methods of observation. Here, methods for locating bumblebee nests were trialled. It was found that a specially trained bumblebee nest detection dog did not discover nests any faster than people who had received minimal instruction. Numbers of nest site searching queens provide a reliable indication of suitable nesting habitat (i.e. places where nests are more likely to be found). In order to investigate aspects of bumblebee nesting ecology wild nests were observed by filming or regular observations by either researchers or members of the public. Some buff-tailed bumblebee (Bombus terrestris) nests were collected and all the bumblebees were genotyped to identify any foreign individuals. A review of British mammalian dietary literature was conducted to identify those that predate bumblebees. Great tits (Parus major) were filmed predating bumblebees at nests and it was clear from the literature and observations that badger (Meles meles), pine martens (Martes martes) and hedgehogs (Erinaceus europaeus) predate bumblebee nests, as well as the wax moth (Aphomia sociella). No evidence for predation by any other vertebrate species was found. Behaviours recorded included parasitism by Psithyrus, apparent nectar theft and possible usurpation by true bumblebees, egg-dumping by foreign queens and drifting and drifter reproduction by foreign workers. These events may cause harm to colonies (for example, through horizontal transmission of pathogens, or exploitation of the host nest’s resources). Alternatively where for example, usurpation by true bumblebees, egg-dumping or drifting is successful, these alternative reproductive strategies may increase the effective population size by enabling a single nest to produce reproductives of more than one breeding female. These data found that wild buff-tailed bumblebees (B. terrestris) nests with a greater proportion of workers infected with Crithidia bombi were less likely to produce gynes than those with fewer infected workers. Gyne production also varied dramatically between years. There is a growing body of evidence that a class of frequently used insecticides called neonicotinoids are negatively impacting bumblebees. An experiment was conducted using commercial colonies of buff-tailed bumblebees (B. terrestris) which were fed pollen and nectar which had been treated with the neonicotinoid imidacloprid at field realistic, sub-lethal levels. Treated colonies, produced 85-90% fewer gynes than control colonies. If this trend is representative of natural nests feeding on treated crops, for example, oilseed rape and field beans or garden flowers, then this would be expected to cause dramatic population declines. In this thesis methods for locating bumblebee nests have been tested, new behaviours have been identified (for example, egg-dumping by queens and predation by great tits) and estimations for rates of fecundity and destruction by various factors have been provided. Doubt has been cast over the status of some mammals as predators of bumblebee nests and estimates for gyne production, nest longevity, etc, have been given. More work is needed, especially observations of incipient nests as this is when the greatest losses are thought to occur.

Made available in DSpace on 2016-06-02T19:29:57Z (GMT). No. of bitstreams: 1 5249.pdf: 4090294 bytes, checksum: 3e43d0f22c6895a3bc1866edf5eafc88 (MD5) Previous issue date: 2012-06-29 / Financiadora de Estudos e Projetos / Nesting is a critical step on bird s life cycle, since nest predation is high all over the world. Predation influences the population dynamics, the community structure and the life history of birds. Birds evolved anti-predatory strategies, which include selection of safer places for nesting. Here we intent to: (i) analyze habitat characteristics selected by adults, and (ii) evaluate the influence of these elements on nests success, and fitness consequences to individuals. We studied the Lesser Elaenia (Elaenia chiriquensis), a migratory bird that breeds in Brazilian Savannas. We conducted the study between 2010 e 2011 in a 100 ha area in the Estação Ecológica de Itirapina, a protected area in São Paulo state, were the Lesser Elaenia is abundant along its breeding season (September to December). We analyzed habitat selection comparing characteristics of used and available patches. We made all tests using chi-square tests, analysis of variance, paired t-tests and permutation tests. We used program MARK to evaluate the influence of all of the parameters on nests success. We created a set of models that included temporal and a set of environmental parameters and used Akaike s Information Criterion to evaluate the adjustment of each model to our data. Adults apparently selected anemochoric plants, with larger crowns and more lichen flakes on stalks, but did not show preference for specific plant species. Individuals also preferred patches with high plant density and high density of Aspidosperma tomentosum, the most used plant as nest substrate. Contrary of our expectations, none of these characteristics influenced nests success. However, some parameters not evaluated for selection, influenced the offspring survival. Vegetation density on nest sites was the most important variable, probably because it helps concealing nests and parental activities. Nest age and time along the breeding season were also important elements and both reduced nests success. Nest predation, habitat selection, and their consequences to the fitness are complex and are related to many variables. The present study contributed with the knowledge on this subject in tropical areas. / A nidificação é uma etapa crítica no ciclo de vida das aves, uma vez que a predação de ninhos é alta em todo o globo. Ela exerce influência na dinâmica das populações, estrutura das comunidades e evolução da história de vida do grupo. Diante disso, evoluíram estratégias antipredação, entre elas, a seleção de hábitats seguros para a nidificação pelos adultos. Assim, nesse trabalho tivemos como objetivos principais (i) conhecer os elementos do hábitat de nidificação selecionados pelos adultos e (ii) avaliar a influência desses elementos no sucesso dos ninhos, de forma a conhecer o valor adaptativo das escolhas dos adultos. Trabalhamos com Elaenia chiriquensis, um Passeriforme migratório que nidifica em áreas de Cerrado no Brasil. Conduzimos o estudo entre 2010 e 2011, em uma área de 100 ha na Estação Ecológica de Itirapina, unidade de conservação localizada no interior paulista, em que E. chiriquensis é abundante na estação reprodutiva (setembro a dezembro). Fizemos as análises de seleção do hábitat de nidificação comparando características das manchas de nidificação às manchas nas imediações, disponíveis aos casais. Usamos testes de Qui- Quadrado, análises de variância (ANOVAs), testes de permutação e testes-t pareados para as variáveis amostradas. Para avaliarmos a influência dessas e de outras características, relacionadas aos ninhos, na sobrevivência da prole, usamos o programa MARK. Criamos modelos que incluíam variáveis temporais e nossas variáveis de interesse e avaliamos, usando o critério de informação de Akaike, o ajuste dos modelos ao nosso conjunto de dados. Os adultos aparentemente selecionaram vegetais anemocóricos, com copa de tamanho maior e maior abundância de liquens nos caules como substrato dos ninhos, mas não exibiram preferência pelas espécies usadas como substrato. Elaenia chiriquensis também mostrou preferência por locais com alta densidade de vegetação lenhosa e alta abundância de Aspidosperma tomentosum, a espécie vegetal mais usada como substrato dos ninhos. Contrariando nossas expectativas, nenhuma dessas características teve influência no sucesso dos ninhos. No entanto, características relacionadas aos ninhos, e que não foram avaliadas quanto à seleção, tiveram influência na sobrevivência da prole. A mais importante delas foi a densidade de vegetação nos sítios de nidificação, que provavelmente reduz as chances de encontros com predadores e oculta a atividade dos adultos. A idade dos ninhos e a influência do tempo ao longo das estações também foram variáveis de peso na explicação dos dados e ambos reduziram as chances de sucesso dos ninhos. A predação de ninhos, a seleção do hábitat de nidificação e as consequências para o fitness dos indivíduos são assuntos de grande complexidade biológica e envolvem diversas variáveis. O presente estudo contribui com o conhecimento acerca do assunto em áreas tropicais.

Nests are key structures for the reproduction of majority of avian species and as such they should be subject to natural selection. Six hypotheses have been suggested to explain variance in avian nest size. In my master thesis I evaluate their validity in the Great Reed Warbler (Acrocephalus arundinaceus). First two hypotheses describe responses of nest size to predation and brood parasitism. These two selection pressures may lead to the reduction of nest size, but no evidence of their impact on nest dimensions was obtained. However, I found a significant but negative relationship between the probability of nest predation and soft nest height. No such relationship was found between the probability of brood parasitism and nest size characteristics. The incidence of brood parasitism was affected only by nest visibility from the nearest cuckoo perch site and distance from open water. More visible nests suffered heavier parasitism while those located deeper in reed beds were better protected from cuckoo parasitism. Another four hypotheses describe selection pressures which favour large nests or some of their functional parts. The thermoregulatory hypothesis, the sexual display hypothesis and the nest support hypothesis did not explain nest size variation. I found support for the clutch size hypothesis,...

<p>This thesis examines risk management in breeding Siberian jays (<i>Perisoreus infaustus</i>), which is indigenous to the northern taiga. Parent behaviour and the nest are cryptic. A new nest is built each year. It is placed on spruce or pine branches close to the trunk and well insulated with lichens, feathers and reindeer hair.</p><p>Nest failure rate was the main factor driving annual variations in jay numbers. The probability for nesting attempts to be successful ranged annually between 0.08 and 0.70. Nest predation was rampant and a main cause of nest failure. Nest predators were mainly other corvids (primarily the Eurasian jay <i>Garrulus glandarius</i>). Habitat quality was the main factor determining the risk of predation. The risk for nest failure due to predation was higher in thinned forests with an open structure and with a high abundance of man-associated corvid species (jays, crows, raven). </p><p>Siberian jay parents show several strategic adjustments in life-history and behaviour to the risk of nest predation. Parents traded reduced feeding rates for a lower predation risk and allocated feeding to low risk situations. Chick provisioning imposes a cost by drawing the attention of visually hunting predators to the location of nests, and parents adjusted their daily routines and avoided exposure by allocating provisioning to times of low activity among nest predators. These strategic adjustments of feeding efforts were estimated to reduce the exposure to nest predators by 26 percent. Also, parents adjusted their reproductive efforts to the perceived presence of predators in a playback experiment. Siberian jays reduced their reproductive investment by laying a smaller clutch size when high risk of nest predation reduced the value of current reproduction, as predicted from life-history theory.</p>

This thesis examines risk management in breeding Siberian jays (Perisoreus infaustus), which is indigenous to the northern taiga. Parent behaviour and the nest are cryptic. A new nest is built each year. It is placed on spruce or pine branches close to the trunk and well insulated with lichens, feathers and reindeer hair. Nest failure rate was the main factor driving annual variations in jay numbers. The probability for nesting attempts to be successful ranged annually between 0.08 and 0.70. Nest predation was rampant and a main cause of nest failure. Nest predators were mainly other corvids (primarily the Eurasian jay Garrulus glandarius). Habitat quality was the main factor determining the risk of predation. The risk for nest failure due to predation was higher in thinned forests with an open structure and with a high abundance of man-associated corvid species (jays, crows, raven). Siberian jay parents show several strategic adjustments in life-history and behaviour to the risk of nest predation. Parents traded reduced feeding rates for a lower predation risk and allocated feeding to low risk situations. Chick provisioning imposes a cost by drawing the attention of visually hunting predators to the location of nests, and parents adjusted their daily routines and avoided exposure by allocating provisioning to times of low activity among nest predators. These strategic adjustments of feeding efforts were estimated to reduce the exposure to nest predators by 26 percent. Also, parents adjusted their reproductive efforts to the perceived presence of predators in a playback experiment. Siberian jays reduced their reproductive investment by laying a smaller clutch size when high risk of nest predation reduced the value of current reproduction, as predicted from life-history theory.

The abundance of Rio Grande wild turkeys (Meleagris gallopavo intermedia) in the southeastern Edwards Plateau of Texas has declined since the late 1970s. Because knowledge of reproductive rates is important to understanding the dynamics of a population, radio-tagged hens were monitored during the 2005–2007 reproductive seasons to evaluate and compare reproductive parameters from areas with both declining and stable population trends. During January–March of 2005–2007, turkey hens were captured and radiotagged on 4 study areas; 2 within a region of stable turkey populations, and 2 within a region of declining populations. Monitoring occurred from January–July each season to determine nest- site locations. Nesting attempts, nest fate, clutch size, initiation date, and nest age were recorded. Nests were monitored ≥3 times weekly in order to estimate production parameters and daily nest survival. Poults were captured by hand and fitted with a 1.2 glue-on transmitter and monitored daily to estimate daily survival. Estimates show production was greater in stable regions than declining regions of the Edwards Plateau. Eighty-four percent of hens attempted to nest in the stable region and 67% attempted in the declining region. Eighteen of 102 nests were successful (≥1 egg hatched), in the stable region and 7 of 60 nests were successful in the declining region. Nest-survival analysis showed an influence of temporal variation within years, yet no differences in nest survival were detected between stable and declining regions. Poult survival also showed no difference between regions. The 2 overall objectives of this study were to determine if nesting parameters and nest survival were limiting factors in Rio Grande wild turkey abundance in the Edwards Plateau. Regional differences in production suggest the cause of the decline in the southeastern portion of the Edwards Plateau could be associated with lower reproductive output and consequently, success. Regional differences in nest survival were not detected, thus not likely to cause differences in turkey abundance between regions.

Made available in DSpace on 2015-04-11T14:02:35Z (GMT). No. of bitstreams: 1 Kellen Fabiane da Silva Pinage.pdf: 968503 bytes, checksum: 287e8546d1bf57097a18d1540c5cc374 (MD5) Previous issue date: 2007-09-21 / Protein structure prediction is a process in Molecular Biology by way of which the 3D structure of a protein is determined based on known structures of other proteins. This is an important process because the structure of a protein is a determinant factor for its function in the cell. Knowing a protein s structure allows scientists to describe the kind of activity that the protein performs in the cell and to develop drugs to treat diseases. The prediction process is based on similarity between the amino acid sequences that form proteins: the structure of a target protein is predicted by re-using knowledge on proteins whose structures are already determined and whose amino acid sequences are similar to the former s. Therefore, knowledge reuse occurs in the process of predicting protein structure, but without employing a domain ontology. In this work, we apply a technique of ontology-driven knowledge re-use in protein structure prediction aiming at improving the prediction process in its efficiency and in the quality of the obtained structures. An experiment has been carried out in which the technique was applied to predict the structure of 286 target sequences. There has been improvement as well as loss of quality of predicted structures, whereas a run time performance gain in 38% of the target structures was observed. / Predição de estrutura de proteína é um processo na Biologia Molecular pelo qual a estrutura 3D de uma proteína é determinada com base em estruturas já conhecidas de outras proteínas. É um processo importante porque a estrutura de uma proteína é um fator determinante para sua função na célula. Conhecendo a estrutura de uma proteína, os cientistas podem descobrir que tipo de atividade a proteína realiza na célula e criar drogas para combater doenças. O processo de predição é baseado na similaridade entre as seqüências de aminoácidos que formam proteínas: a estrutura de uma proteína alvo é predita reusando conhecimento de proteínas cujas estruturas já foram determinadas e suas seqüências de aminoácidos são similares à seqüência alvo. Portanto, reuso de conhecimento ocorre no processo de predição de estrutura de proteína, mas sem a utilização de uma ontologia de domínio. Neste trabalho, nós aplicamos uma técnica de reuso de conhecimento baseado em ontologia na predição de estrutura de proteína com o objetivo de melhorar o processo de predição em sua eficiência e qualidade das estruturas obtidas. Um experimento foi realizado no qual a técnica foi aplicada para predizer a estrutura de 286 seqüências alvo. Houve melhorias e perdas de qualidade das estruturas preditas, ao passo que um ganho de performance (tempo de execução) foi observado em 38% das seqüências alvo.

No description available.

The purpose of this research was to determine how predator control influences nest survival and changes in life history strategies of birds. All studies were conducted at two sites: one site had very little mammal control, while the other site is a 'mainland island' in which all introduced mammals were trapped or poisoned. Nest survival rates of introduced and native species were compared between the two sites by locating and monitoring nests of nine species. I found that mammalian predator control increased nest survival rates of both introduced and native species, but the incrase of nest survival was more pronounced in native species. The influence of predator control on the plasticity of life history strategies in introduced and native New Zealand birds was also examined. Some life history strategies (e.g. time spent incubating, frequency of visits to the nest) changed significantly in the area with predator control, while other life history traits (e.g. clutch size) did not vary between areas. I found that both introduced and native New Zealand birds changed a variety of life history traits and that the changes were likely a plastic response to the recent change in predator numbers. As it has been suggested that birds may become less responsive to mammals when predators are controlled, I tested the response of birds to a model of a feral cat. Birds in the predator control area were significantly less likely to recognise the cat model as a potential threat. This suggests the recognition of predators can be rapidly lost from a population. My research confirms that mammal control can increase nest success of native species, but reductions in predator numbers can also change a variety of life history traits and behaviours. As the removal of mammalian predators also appears to make birds less responsive to potential predators, it is important for continued mammalian control once management has begun. Otherwise, any reintroduction of predatory mammals into controlled sites would likely place such bird populations at greater risk as they would have behaviours suited to an environment with lowered nest predation risk.

From being an unemployment success story, Sweden was during the 1990s thrown into a European normality, with apparent high and persistent unemployment. This has made unemployment a central issue in the Swedish public debate as a social problem directly affecting hundreds of thousands of individuals. In the public debate there is however no consensus on what characterises the experience of unemployment. One perspective emphasises the role of employment for self-realisation. Unemployment here becomes a very destructive experience, due to the psychosocial value attached to employment. An alternative perspective instead views employment as a necessary evil that brings little satisfaction to those who participate in it. From this perspective unemployment mean very little to those struck by it outside the possible negative effects on income (which are minimised by the welfare state). The objective of this thesis has been to move beyond the postulated truths of what the experience of unemployment means. It uses an empirical approach in order to investigate the consequences of unemployment for mental well-being, and to develop an understanding of the reasons for this relationship. The following conclusions can be drawn from the five articles that make up the thesis. In line with previous international and Swedish research, the thesis shows that unemployment as compared to employment is in general a distressing experience. This does however not mean that we can draw the simple conclusion that unemployment represents misery and employment represents the absence of misery. The thesis finds the relationship to be more complex than so. There is a need to take into account more of the possible variations in status available both on and outside the labour market. Different exit routes from unemployment were found to have different consequences for the mental well-being of the unemployed individual. Further, the evidence in the thesis shows that there is variation in the impact of unemployment on mental well-being within the unemployment group. We should, thus, not talk about the experience of unemployment, but rather about varying unemployment experiences. The general effect of unemployment on mental well-being, and the variation in the unemployment experience, was in turn shown to be mainly dependent on two factors. Firstly on the psychosocial need for employment in a society where employment is the norm. Secondly, on the economic need for employment in a society where employment, as the thesis also shows, for many still is necessary for adequate economic resources. / <p>Härtill 5 uppsatser.</p> / digitalisering@umu