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Population Dynamics of Threatened Piping Plovers on the Niobrara River, NebraskaFriedrich, Meryl J. 11 July 2018 (has links)
Prairie rivers of the Great Plains, USA, provide important habitat for the federally threatened piping plover (“plover”, Charadrius melodus). Plovers nest on open to sparsely vegetated river sandbars, and their demographic rates are closely linked to habitat availability and quality, as well as river flow. The Niobrara River in northern Nebraska has supported 22–41% of the state’s plovers since species listing in 1986, but the population and habitat are relatively understudied, and both have declined since 2010. The objectives of this study were to understand plover demography, habitat, and the role of the Niobrara in the regional plover population.
Periods of high river flow promote creation and maintenance of suitable sandbar nesting habitat, but increased river flow during the plover breeding season can decrease nest and chick survival. We estimated the effect of daily peak river flow on survival rates of 115 nests and 66 chicks on the Niobrara River, 2010–2016, using logistic exposure and Cormack-Jolly-Seber models, respectively. We monitored 1,874 banded hatch-year and adult birds across the regional population (Niobrara River, Lewis and Clark Lake, Gavins Point Reach segment of the Missouri River), and used multi-state mark-recapture models to estimate survival and inter-annual dispersal probabilities among sites relative to habitat availability. We developed land cover datasets from high-resolution aerial imagery to quantify suitable habitat and compare the relative effects of habitat characteristics on nest-site selection and nest success for a subset of years (2010, 2012, 2014, and 2016) using logistic regression models. We included data from a sympatric nester with similar nesting habitat needs, the interior least tern (“tern”, Sternula antillarum athalassos), to improve precision of our models. We compared 63 plover and 92 tern nests to 292 random unused points, and 73 successful (hatched ≥1 egg) to 79 failed nests.
Low nest and chick survival and high emigration from the Niobrara appear to be important factors contributing to population decline. Daily nest and chick survival were negatively related to river flow. Nest-site selection was based primarily on distance to the river bank (i.e., the nearest potential source of predators), yet flooding (eggs submerged or washed out of the nest bowl during increased river flow) caused at least as many nest failures as predation. Nests predominantly were surrounded by dry sand habitat, indicating some degree of flood avoidance, but were no farther from water than random, and drier nest sites were no less likely to fail. Dispersal occurred throughout the regional population, but plovers were more likely to leave the Niobrara than to enter it. Expansive flood-created sandbars on the Missouri River, concurrent with a trend towards more vegetated and saturated habitat on the Niobrara, may have drawn birds from the Niobrara population, especially those that dispersed to the Niobrara during sustained Missouri River flooding 2010–2011.
The outsized negative effect of flooding on nest success, the lack of protection afforded by dry sand nest sites, and selection for nesting habitat based more strongly on predator avoidance than flood avoidance suggest that plovers may have face more frequent and intense levels of breeding season flooding than is typical. Identifying and promoting the processes that contribute to creation and maintenance of high-elevation sandbars on the Niobrara is an important next step towards effective management of nesting birds. / Master of Science / Prairie rivers of the Great Plains, USA, provide important habitat for a federally threatened shorebird, the piping plover (“plover”, Charadrius melodus). During their breeding season (April–August), plovers nest and raise chicks on open to sparsely vegetated areas of river sandbars, and their survival and reproductive success are closely tied to amount and quality of sandbar habitat. The number of plovers on the Niobrara River in northeast Nebraska has declined since 2010, and in this study our objectives were to monitor nests, chicks, and adult birds to document plover survival, movement among neighboring sites, reproductive success, and habitat changes on the Niobrara from 2010–2016.
Because plovers nest on the sand, they can lose nests and chicks when river flow increases and washes over sandbars (“flooding”). We found that nest and chick survival sharply decreased when river flow was high. Plovers chose nest sites in dry sand areas, which are typically the tallest part of a sandbar and most protected from flooding, but these nests were no more likely to hatch than those in areas with wetter (lower elevation) sand. Plovers primarily chose nest sites far from the river bank, which was the nearest potential source of predators, yet flooding caused at least as many nest failures as predation. Plovers moved between the Niobrara and nearby Missouri River, but overall were much more likely to leave the Niobrara than to enter it. Expansive sandbar creation on the Missouri River, concurrent with a trend towards lower-quality (more vegetated and saturated) habitat on the Niobrara, may have drawn birds from the Niobrara population, especially those displaced from the Missouri during sustained flooding 2010–2011.
Movement to the Missouri River and low nest and chick survival due to flooding contributed to population decline on the Niobrara. The outsized effect of flooding on nest success, the lack of protection afforded by dry sand nest sites, and selection for nesting habitat based more strongly on predator avoidance than flood avoidance suggests that plovers face more frequent and intense levels of breeding season flooding than is typical. Identifying and promoting the processes that contribute to creation and maintenance of high-elevation sandbars on the Niobrara is an important next step towards effective management of nesting birds.
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Reproductive ecology and latitudinal variation of three cavity nesting duck species in Eastern United StatesMentges, Hunter Elijah 13 August 2024 (has links) (PDF)
Survival of females, nests, and ducklings strongly influence annual recruitment in North American ducks. Studies of cavity-nesting ducks using nest boxes, such as wood ducks (Aix sponsa), hooded merganser (Lophodytes cucullatus) and black-bellied whistling duck (Dendrocygna autumnalis) historically have investigated extrinsic factors, such as nest predation, and how it influenced nest success. For my study, I evaluated data from 1,403 monitored nest boxes collected from eight states, 2020–2022. I studied intrinsic characteristics related to reproduction, such as egg and clutch sizes, and eggshell strength in the 3 cavity-nesting ducks. Variables including clutch size, egg mass, parasitism, and onset of incubation influenced reproductive success of wood ducks. Latitude also influenced clutch size in wood ducks, where for every 14.3° increase in latitude, I found one more egg per clutch. Hooded mergansers had the strongest eggshells and eggshell composition varied across latitude in hooded merganser, but not in wood ducks.
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Movement ecology and nest-site selection of rock iguanas across a gradient of anthropogenic disturbanceWehsener, James Walter 13 August 2024 (has links) (PDF)
Analysis of animal movement has been integrated into a framework of four components: internal state, motion capacity, navigation capacity, and external factors (Nathan et al., 2008). We used this framework to enhance understanding of movement behavior in the 15 West Indian rock iguana (Cyclura) taxa and to inform conservation management. Our review found that adult female Cyclura large-scale movement is primarily driven by nesting and migrations. Nest site selection also influences hatchling dispersal, but few studies identify preferred habitats for nesting females. Anthropogenic impacts on nesting ecology are largely unexplored, especially in Cyclura carinata. We studied C. carinata nesting ecology in a threatened population, aiming to identify habitat preferences and assess human impact on nesting success. This research fills gaps by addressing both proximate causes of movement and ultimate outcomes of movement decisions, essential for developing effective conservation strategies. Understanding both aspects is crucial for mitigating threats to Cyclura populations.
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Nest box use by Common Goldeneye (Bucephala clangula) in the Chena River System, Interior AlaskaPorter, Riley D. 13 August 2024 (has links) (PDF)
Various environmental and demographic factors can influence nest site selection in cavity-nesting birds. Nest site choices may involve females’ familiarity with local habitats or resources, or information gained about the quality of a potential nest site. Common Goldeneyes (Bucephela clangula) are philopatric, yet some proportions of available nest boxes commonly remain vacant during breeding seasons throughout the birds’ range. As part of a long-term (1997-2022) study of Common Goldeneyes, I monitored 150 nest boxes in 2021 and 2022 in the Chena River State Recreation Area, Fairbanks, Alaska. I studied use of nest boxes based on box- and landscape specific habitat characteristics, and long-term trends in nest boxes, such as those used or not used by goldeneyes. Nest boxes that were more visible and proximal to wetland habitats positively influenced use, as did breeding population size, recent success, time since the last depredation event, and egg parasitism rates.
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<b>A Case Study for a Language Nest in Limonese Creole</b>Margie Cubillo Araya (20313723) 10 January 2025 (has links)
<p dir="ltr">Limonese Creole is an endangered Creole language spoken in Costa Rica. During the last decade, researchers alongside the community have produced various studies on the language structure, as well as revitalization efforts such as an orthography, translations, workshops, presentations, and a bill to recognize Limonese Creole as a language in the Political Constitution of the country, among others. However, can a mere political recognition change the language reality and encourage people to use the language more? The answer is simple, no. Hence, this case study aims to propose a curriculum for a Limonese Creole Language Nest that will contribute as an instrument for empowering the community and revitalizing their language. The language nest model portrays an innovative, immersion-based approach to early childhood language education and revitalization (Chambers, 2015). In language nests, older members of the community provide care for children while they speak their language with them. The purpose is to expose children as much as possible to the language so they will acquire native fluency. The long-term projection of this study is to set the basis for a Limonese Creole Language Nest curriculum as an effective vehicle for revitalizing the language.</p>
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Gone with the rain: negative effects of rainfall on male reproductive success in a nest-building arachnid / E a chuva levou: efeitos negativos da precipitação sobre o sucesso reprodutivo dos machos em um aracnídeo construtor de ninhosValle, Andres Rojas 26 June 2018 (has links)
In nest-building species, offspring survival and reproductive success of parental individuals are strongly influenced by nest location and quality. Thus, quantifying the influence of abiotic conditions on nest integrity is important to predict the effects that weather variability may have on offspring survival and parental reproductive success. Here we investigated how rainfall affects nest integrity and how nest integrity influences male attractiveness and nest tenure. Our study species was the harvestman Quindina limbata, in which males build cup-like mud nests on fallen logs and protect the eggs against predators and fungi infestation. Our dataset is based on 12 months of regular inspections of over 150 nests in a tropical rainforest from Costa Rica. We found that 43% of the nests were destroyed by rainfall. The drag force promoted by rainfall running on the log surface negatively affected nest integrity by decreasing the wall perimeter and the floor area. The intensity of fungi cover was not explained by nest position or by precipitation. No matter the body size of the owner males, nests with high integrity received more eggs than nests with low integrity. Curiously, nests with high values of fungi cover received more eggs. Finally, nest integrity and fungi cover did not affect nest tenure, but the probability of males abandoning their nests increased with time they did not receive eggs. Considering that intense rainfall occurs all year long in tropical forests, the best males can do to decrease the chances of nest destruction is to select protected places to build their nests. Protected sites may keep nest structure better preserved, improve offspring survival, attract more females, and ultimately increase male reproductive success / Em espécies que constroem ninhos, a sobrevivência da prole e o sucesso reprodutivo dos indivíduos parentais são fortemente influenciados pela localização e qualidade dos ninhos. Portanto, quantificar a influência das condições abióticas sobre a integridade dos ninhos é importante para prever os efeitos que a variabilidade climática pode ter na sobrevivência da prole e no sucesso reprodutivo dos pais. Neste estudo, investigamos como a chuva influencia a integridade dos ninhos e como a integridade dos ninhos influencia a atratividade masculina e o tempo de posse do ninho. Nossa espécie de estudo foi o opilião Quindina limbata, em que os machos constroem ninhos de barro em troncos caídos e protegem os ovos contra predadores e infestação por fungos. Nosso conjunto de dados é baseado em 12 meses de inspeções regulares de mais de 150 ninhos em uma floresta tropical na Costa Rica. Descobrimos que 43% dos ninhos foram destruídos pela chuva. A força de arrasto promovida pela chuva na superfície dos troncos caídos influenciou negativamente a integridade dos ninhos, diminuindo o perímetro da parede e a área do piso. A intensidade de cobertura de fungos não foi explicada pela posição do ninho ou pela precipitação. O tamanho corporal dos machos não influenciou o ganho de ovos, mas ninhos com alta integridade receberam mais ovos do que ninhos com baixa integridade. Curiosamente, ninhos com altos valores de cobertura de fungos receberam mais ovos. Por fim, a integridade dos ninhos e a cobertura de fungos não influenciaram o tempo de posse do ninho, mas a probabilidade de os machos abandonarem seus ninhos aumentou com o tempo em que não receberam ovos em seus ninhos. Considerando que temporais ocorrem durante todo o ano em florestas tropicais, os melhores machos devem selecionar locais protegidos para construção dos seus ninhos a fim de diminuir as chances de destruição promovida pela chuva. Locais protegidos podem manter a estrutura do ninho melhor preservada, melhorar a sobrevivência da prole, atrair mais fêmeas e, finalmente, aumentar o sucesso reprodutivo dos machos
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Ekologie lesního společenstva ptáků na Papui Nové GuineiCHMEL, Kryštof January 2017 (has links)
The thesis addresses several aspects of ecology of lowland rainforest avifauna in Papua New Guinea. It describes spatial and temporal distributional patterns of abundance and diversity of bird community and different feeding guilds. More specifically, spatial patterns were explored in relation to topography, tree species composition, forest structure including vertical forest strata and inter-specific associations. The thesis also focuses on nest survival in continuous and fragmented forest, particularly in relation to nest predation.
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Gone with the rain: negative effects of rainfall on male reproductive success in a nest-building arachnid / E a chuva levou: efeitos negativos da precipitação sobre o sucesso reprodutivo dos machos em um aracnídeo construtor de ninhosAndres Rojas Valle 26 June 2018 (has links)
In nest-building species, offspring survival and reproductive success of parental individuals are strongly influenced by nest location and quality. Thus, quantifying the influence of abiotic conditions on nest integrity is important to predict the effects that weather variability may have on offspring survival and parental reproductive success. Here we investigated how rainfall affects nest integrity and how nest integrity influences male attractiveness and nest tenure. Our study species was the harvestman Quindina limbata, in which males build cup-like mud nests on fallen logs and protect the eggs against predators and fungi infestation. Our dataset is based on 12 months of regular inspections of over 150 nests in a tropical rainforest from Costa Rica. We found that 43% of the nests were destroyed by rainfall. The drag force promoted by rainfall running on the log surface negatively affected nest integrity by decreasing the wall perimeter and the floor area. The intensity of fungi cover was not explained by nest position or by precipitation. No matter the body size of the owner males, nests with high integrity received more eggs than nests with low integrity. Curiously, nests with high values of fungi cover received more eggs. Finally, nest integrity and fungi cover did not affect nest tenure, but the probability of males abandoning their nests increased with time they did not receive eggs. Considering that intense rainfall occurs all year long in tropical forests, the best males can do to decrease the chances of nest destruction is to select protected places to build their nests. Protected sites may keep nest structure better preserved, improve offspring survival, attract more females, and ultimately increase male reproductive success / Em espécies que constroem ninhos, a sobrevivência da prole e o sucesso reprodutivo dos indivíduos parentais são fortemente influenciados pela localização e qualidade dos ninhos. Portanto, quantificar a influência das condições abióticas sobre a integridade dos ninhos é importante para prever os efeitos que a variabilidade climática pode ter na sobrevivência da prole e no sucesso reprodutivo dos pais. Neste estudo, investigamos como a chuva influencia a integridade dos ninhos e como a integridade dos ninhos influencia a atratividade masculina e o tempo de posse do ninho. Nossa espécie de estudo foi o opilião Quindina limbata, em que os machos constroem ninhos de barro em troncos caídos e protegem os ovos contra predadores e infestação por fungos. Nosso conjunto de dados é baseado em 12 meses de inspeções regulares de mais de 150 ninhos em uma floresta tropical na Costa Rica. Descobrimos que 43% dos ninhos foram destruídos pela chuva. A força de arrasto promovida pela chuva na superfície dos troncos caídos influenciou negativamente a integridade dos ninhos, diminuindo o perímetro da parede e a área do piso. A intensidade de cobertura de fungos não foi explicada pela posição do ninho ou pela precipitação. O tamanho corporal dos machos não influenciou o ganho de ovos, mas ninhos com alta integridade receberam mais ovos do que ninhos com baixa integridade. Curiosamente, ninhos com altos valores de cobertura de fungos receberam mais ovos. Por fim, a integridade dos ninhos e a cobertura de fungos não influenciaram o tempo de posse do ninho, mas a probabilidade de os machos abandonarem seus ninhos aumentou com o tempo em que não receberam ovos em seus ninhos. Considerando que temporais ocorrem durante todo o ano em florestas tropicais, os melhores machos devem selecionar locais protegidos para construção dos seus ninhos a fim de diminuir as chances de destruição promovida pela chuva. Locais protegidos podem manter a estrutura do ninho melhor preservada, melhorar a sobrevivência da prole, atrair mais fêmeas e, finalmente, aumentar o sucesso reprodutivo dos machos
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Úloha hnízda při reprodukci rákosníka velkého / The role of nest in reproduction of the Great Reed WarblerJelínek, Václav January 2017 (has links)
7 Abstract Bird nests protect eggs and nestlings, allowing the parents to leave their offspring and subsequently return to them. Their thermoregulatory properties reduce energetic costs of incubation and brooding of nestlings. For all these reasons, nests are key structures for the reproduction of a majority of avian species and as such they should be subject to natural selection. Several hypotheses describing selection pressures which affect the size of nests or some of their parts have been suggested. In my PhD thesis, I investigated some of them in the great reed warbler (Acrocephalus arundinaceus) - an open nesting passerine species with very variable nest size. For this purpose, I used a large dataset of several hundred measured great reed warbler nests, nest enlargement experiments and an experiment with artificial nests. In accordance with previous studies, we did not find that nest size affects the probability of common cuckoo (Cuculus canorus) brood parasitism, while it was influenced by other factors, such as timing of breeding, reed density around the nest and nest visibility from the nearest potential cuckoo perch site. More interestingly, we found that cuckoos adjust their nest-searching strategy in relation to availability of host nests. When host nests were scarce, cuckoos parasitized all of...
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外籍教師在台灣升學導向高中之教學信念及實踐 / Teaching beliefs and instructional practices: A Case study of a native speaking english teacher in a college-bound senior high school in Taiwan黃久芳 Unknown Date (has links)
本研究旨在探討在台灣升學導向高中任教之外籍教師在面對不同議題時之信念是否受到大學聯考的影響,以及其教學信念及實踐是否一致。
為了能夠深入了解外籍教師的教學信念,本研究採用質性研究法來進行資料採集及分析,所使用的資料採集工具為訪談、課室觀察及文件分析。除了訪談一名擁有三年私立升學導向高中教學經驗的女性教師,研究者更進一步訪談該校外語中心主任以期能了解該校對其外籍老師的要求及期待。研究結果呈現此外籍教師對於學習、教學、英語、大學入學考試、台灣教育以及本籍及外籍教師間之異同的信念及看法。
在本研究最後,研究者也針對研究結果提出了建議,以期能提供給教育當局、學校以及學者作為參考。 / The purpose of this study is to explore the beliefs of a native English speaking teacher (NEST) in a college-bound senior high school in Taipei City and to see if the JUEE has influence on her teaching beliefs. Instructional practices are used to compare with the NEST’s beliefs to check the consistency between them.
In order to have a complete picture of NEST’s beliefs, the researcher made use of qualitative research methods in this study and selected an experienced NEST who was currently teaching in a private senior high school in Taipei City. By adopting three data collection methods: semi-structured interviews, classroom observations and document analyses, the researcher collected the data from the NEST. Furthermore, the researcher also interviewed the director of Foreign Language Center to see if the NEST’s beliefs were congruent with the school’s expectations. The data were analyzed to present the NEST’s beliefs about learning, teaching, English, the JUEE, the educational system in Taiwan and the differences between NESTs and NNESTs.
Based on the results, the implications were offered for the policy makers and the institutions as well as the recommendations for the future researchers.
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