Open Access. Powered by Scholars. Published by Universities.®

Ecology and Evolutionary Biology Commons

Open Access. Powered by Scholars. Published by Universities.®

University of Massachusetts Amherst

2017

Discipline
Keyword
Publication
Publication Type

Articles 1 - 14 of 14

Full-Text Articles in Ecology and Evolutionary Biology

Specialization And Trade-Offs In Plant-Feeding Insects, Daniel Peterson Nov 2017

Specialization And Trade-Offs In Plant-Feeding Insects, Daniel Peterson

Doctoral Dissertations

The immense diversity of life on Earth has been attributed to the partitioning of available resources into ecological niches, but it is not obvious what determines the niche size of each species. For example, most plant-feeding insects consume only one or a few closely-related host-plant species despite the advantages of having a broader diet. Many researchers have therefore suggested that the evolution of broad diets in plant-feeding insects must be constrained by genetic trade-offs between adaptations to alternative host-plants. Despite its intuitive feel, however, little empirical evidence in support of the trade-off hypothesis has emerged from decades of experimental studies …


All Roads Lead To Weediness: Stories About Weedy Rice Origins, Weedy Genes And Weed Competitiveness, Zhongyun Huang Nov 2017

All Roads Lead To Weediness: Stories About Weedy Rice Origins, Weedy Genes And Weed Competitiveness, Zhongyun Huang

Doctoral Dissertations

Weedy rice (Oryza spp.), a weedy relative of cultivated rice (O.sativa), infests and persists in cultivated rice fields worldwide. Many weedy rice populations have evolved similar adaptive traits, considered part of the ‘agricultural weed syndrome’, making this an ideal model to study the genetic basis of parallel evolution. Using population genetics analyses of South Asian and US weedy rice, my research reveals multiple independent evolution events giving rise to weed groups in the two geographic areas. Weeds in South Asia have highly heterogenous genetic backgrounds, with contributions from both cultivated varieties (aus and indica) …


Modelling Bird Migration With Motus Data And Bayesian State-Space Models, Justin Baldwin Oct 2017

Modelling Bird Migration With Motus Data And Bayesian State-Space Models, Justin Baldwin

Masters Theses

Bird migration is a poorly-known yet important phenomenon, as understanding movement patterns of birds can inform conservation strategies and public health policy for animal-borne diseases. Recent advances in wildlife tracking technology, in particular the Motus system, have allowed researchers to track even small flying birds and insects with radio transmitters that weigh fractions of a gram. This system relies on a community-based distributed sensor network that detects tagged animals as they move through the detection nodes on journeys that range from small local movements to intercontinental migrations. The quantity of data generated by the Motus system is unprecedented, is on …


Direct And Indirect Effects Of Climate On Bird Abundance Along Elevation Gradients In The Northern Appalachians, Timothy Duclos Oct 2017

Direct And Indirect Effects Of Climate On Bird Abundance Along Elevation Gradients In The Northern Appalachians, Timothy Duclos

Masters Theses

The stratification of bird species along elevational gradients is widely reported, with montane bird communities typically characterized by distinctive species occurring in relatively small and isolated populations; as such, these species are the subject of considerable interest to ecologists and conservationists. The stratification of species along elevation is largely attributed to compressed climatic zonation. Recent evidence that bird species are shifting up in elevation has fueled speculation that these species are tracking their climactic niches in response to climate change. However, there is also evidence plant communities are shifting in elevation, presenting a potential additional mechanism explaining changes observed in …


Processing Conservation Indicators With Open Source Tools: Lessons Learned From The Digital Observatory For Protected Areas, Lucy Bastin, Andrea Mandrici, Luca Battistella, Grégoire Dubois Sep 2017

Processing Conservation Indicators With Open Source Tools: Lessons Learned From The Digital Observatory For Protected Areas, Lucy Bastin, Andrea Mandrici, Luca Battistella, Grégoire Dubois

Free and Open Source Software for Geospatial (FOSS4G) Conference Proceedings

The European Commission has a commitment to open data and the support of open source software and standards. We present lessons learnt while populating and supporting the web and map services that underly the Joint Research Centre's Digital Observatory for Protected Areas. Challenges include: large datasets with highly complex geometries; topological inconsistencies, compounded by reprojection for equal-area calculations; multiple different representations of the same geographical entities, for example coastlines; licensing requirement to continuously update indicators to respond to monthly changes in the authoritative data. In order to compute and publish an array of indicators, we used a range of open …


Botswana’S Elephant-Back Safari Industry – Stress-Response In Working African Elephants And Analysis Of Their Post-Release Movements, Tanya Lama Jul 2017

Botswana’S Elephant-Back Safari Industry – Stress-Response In Working African Elephants And Analysis Of Their Post-Release Movements, Tanya Lama

Masters Theses

Understanding how African elephants (Loxodonta africana) respond to human interactions in ecotourism operations is critical to safeguarding animal and human welfare and sustaining wildlife ecotourism activities. We investigated the stress response of elephants to a variety of tourist activities over a 15-month period at Abu Camp in northern Botswana. We compared fecal glucocorticoid metabolite (FGM) concentrations across three elephant groups, including: eight elephants in an elephant-tourism operation (Abu herd), three elephants previously reintroduced back into the wild from the Abu herd, and wild elephants. There were no differences in FGM concentrations between the three groups of elephants. The highest observed …


Biology, Molecular Systematics, Population Dynamics And Control Of A Stem Gall Wasp, Zapatella Davisae (Hymenoptera: Cynipidae), Monica Davis Jul 2017

Biology, Molecular Systematics, Population Dynamics And Control Of A Stem Gall Wasp, Zapatella Davisae (Hymenoptera: Cynipidae), Monica Davis

Doctoral Dissertations

Gall wasps are phytophagous insects that often go unnoticed, however, when they are released from their natural enemies, they have the capacity to outbreak and cause extensive foliar damage. One such outbreaking pest, Zapatella davisae, causes significant damage and mortality to black oak, Quercus velutina. In recent years, black oak decline has been documented in Long Island, New York and coastal New England. Little is known about the lifecycle, distribution or population dynamics of Zapatella davisae and the taxonomy of the species is still unclear. My first study described the biology and distribution of Z. davisae. Zapatella …


The Effects Of Anthropogenic Stress On Nitrogen-Cycling Microbial Communities In Temperate And Tropical Soils, George S. Hamaoui Jr. Jul 2017

The Effects Of Anthropogenic Stress On Nitrogen-Cycling Microbial Communities In Temperate And Tropical Soils, George S. Hamaoui Jr.

Doctoral Dissertations

In this dissertation several research studies are discussed that characterize the effects of anthropogenic, or human-induced, stress on both ammonia-oxidizing and total bacterial soil microbial communities. The disturbances of land-use change in tropical, South American rainforests and artificial warming and nitrogen (N) fertilization in temperate, North American forests were investigated as these disturbances represent past and current disturbances caused by human landscape alteration and climate change. Initially, the response of soil ammonia-oxidizing microbial communities to land-use change from primary rainforest to pasture and, finally, back to secondary forest was determined. Next, these analyses of land-use change effects were expanded to …


The Role Of Phenotypic Integration In Mammalian Tooth Function And Jaw Morphological Diversity, Andrew Conith Jul 2017

The Role Of Phenotypic Integration In Mammalian Tooth Function And Jaw Morphological Diversity, Andrew Conith

Doctoral Dissertations

Here I investigate how two major components of the mammalian feeding system, teeth and jaws, are influenced by functional, environment, and developmental factors. First, I build physical models of the molars from two early mammals, Morganucodon and Kuehneotherium, and compare their ability to process a proxy food item. Early mammals were under strong selection to reduce metabolic costs, so any savings in energy during feeding would be advantageous. I tested the ability of both mammals to process a hard and soft food item with material properties similar to that of the insects they would have likely consumed. Morganucodon was …


Burrowing And Walking Mechanisms Of North American Moles, Yi-Fen Lin Jul 2017

Burrowing And Walking Mechanisms Of North American Moles, Yi-Fen Lin

Doctoral Dissertations

Moles (Family Talpidae) are a classic example of extreme specialization, in their case highly derived forelimb morphologies associated with burrowing. Despite many observations of mole burrows and behaviors gathered in the field, we know very little about how and how well moles use their forelimbs to dig tunnels and to walk within the built tunnels to collect and transport food. The first chapter investigates the effect of soil compactness on two sympatric mole species under controlled laboratory conditions. My results demonstrate that increasing soil compactness impedes tunneling performance as evidenced by reduced burrowing speed, increased soil transport, shorter tunnels, shorter …


Evaluation Of The Recreational Catch-And-Release Fishery For Golden Dorado Salminus Brasiliensis In Salta, Argentina: Implications For Conservation And Management, Tyler Gagne Mar 2017

Evaluation Of The Recreational Catch-And-Release Fishery For Golden Dorado Salminus Brasiliensis In Salta, Argentina: Implications For Conservation And Management, Tyler Gagne

Masters Theses

Golden dorado (Salminus brasiliensis, Cuvier, 1816) is increasing in popularity as a target for recreational anglers practicing catch-and-release (C&R) in northern Argentina and bordering countries. However, to date no research has looked at the potential social and ecological implications of growth in this recreational fishery. The first manuscript of this thesis assessed the consequences of C&R on golden dorado captured by anglers on the Juramento River in Salta, Argentina. This evaluation examined physical injury, physiological stress, reflex impairment, and short term post-release behavior to develop a clear set of evidence-based best practices for C&R. In addition, the Juramento …


Methods For Incorporating Ecological Impacts With Climate Uncertainty To Support Robust Flood Management Decision-Making, Caitlin M. Spence Mar 2017

Methods For Incorporating Ecological Impacts With Climate Uncertainty To Support Robust Flood Management Decision-Making, Caitlin M. Spence

Doctoral Dissertations

Modern and historic flood risk management involves accommodating multiple sources of sources of uncertainty and potential impacts across a broad range of interrelated sectors. Sources of uncertainty that affect planning include internal climate variability, anthropogenic changes such as land use and system performance expectations, and more recently changes in climatology that affect the resources supporting the system. Flood management systems potentially impact human settlements within and beyond the systems’ scope of planning, local weather patterns, and associated ecological systems. Federal guidelines across nations have called for greater consideration of uncertainty and impacts of water resources planning projects, but methods for …


Spatial Ecology Of Black Bears (Ursus Americanus) In Newfoundland, Canada, Nathaniel D. Rayl Mar 2017

Spatial Ecology Of Black Bears (Ursus Americanus) In Newfoundland, Canada, Nathaniel D. Rayl

Doctoral Dissertations

Although black bears (Ursus americanus) are among the most studied mammals in the world, little is known about their ecology in Newfoundland, Canada. I investigated the spatial ecology of black bears on the island, focusing on unusual movements during the denning period and their role as caribou (Rangifer tarandus) calf predators. I investigated the influence of climatic conditions (rainfall) and anthropogenic disturbance on the rate of den abandonment for black bears in Newfoundland, a population with an unusually high rate of abandonment given its northern latitude. I found no evidence that rainfall or anthropogenic disturbance played …


Sex-Biased Oviposition By A Nursery Pollinator On A Gynodioecious Host Plant: Implications For Breeding System Evolution And Evolution Of Mutualism, Laura A. D. Doubleday, Lynn S. Adler Jan 2017

Sex-Biased Oviposition By A Nursery Pollinator On A Gynodioecious Host Plant: Implications For Breeding System Evolution And Evolution Of Mutualism, Laura A. D. Doubleday, Lynn S. Adler

Biology Department Faculty Publication Series

Dioecy, a breeding system where individual plants are exclusively male or female, has evolved repeatedly. Extensive theory describes when dioecy should arise from hermaphroditism, frequently through gynodioecy, where females and hermaphrodites coexist, and when gynodioecy should be stable. Both pollinators and herbivores often prefer the pollen-bearing sex, with sex-specific fitness effects that can affect breeding system evolution. Nursery pollination, where adult insects pollinate flowers but their larvae feed on plant reproductive tissues, is a model for understanding mutualism evolution but could also yield insights into plant breeding system evolution. We studied a recently established nursery pollination interaction between native Hadena …