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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

Foraging activity, habitat use, development of juveniles, and diet of the greater horseshoe bat (Rhinolophus ferrumequinum - Schreber 1774) in south-west England

Duverge, Paul Laurent January 1996 (has links)
No description available.
2

An investigation into integrating knowledge for conservation

Evely, Anna Clair January 2010 (has links)
This thesis analyses the integration of knowledge (disciplinary, expert and lay) in order to contribute to the understanding of how knowledge can be integrated for conservation.  Specifically, the thesis asks: a) how the knowledge of social and natural sciences can be integrated to better manage social-ecological systems; b) what the barriers are to integrating different types of knowledge; c) what the outcomes are of integrating different forms of knowledge; d) what type of participation can best sustain action; and e) how participation can improve adaptive capacity. In Chapter 3 the underlying philosophies of the social and natural sciences are mapped out and evaluated, demonstrating how taking one philosophical stance over another influences project methodology and outcome.  The mapping process may also benefit knowledge integration by enabling researchers to make their underlying assumptions explicit.  In Chapter 4 current cross-disciplinary research in conservation is analysed: results suggests more integrative research (interdisciplinary or trans-disciplinary) has a higher impact on practitioners whereas less integrative research has a higher impact on colleagues.  Using conservation case studies from England, Scotland and Wales, Chapters 5 and 6 investigate some claims made for participation in conservation.  Chapter 5 analyses the satisfaction of participants with implications for participant recruitment and retention. Chapter 6 evaluates how participation and how particular participatory approaches may influence participant learning.  Results indicate a strong link between the integration of participants and types of learning that are considered to build adaptive capacity. Findings indicate that the approach taken to integrating knowledge can directly affect who benefits from the research, methodological flexibility participant satisfaction and learning.
3

Factors influencing nest survival of white-tipped doves in the lower Rio Grande Valley, Texas

Giese, Jordan Clarence 03 March 2017 (has links)
<p> The white-tipped dove (<i>Leptotila verreauxi</i>) is a sedentary, secretive columbid that ranges from Argentina to the Lower Rio Grande Valley (LRGV) of south Texas. Since its designation as a game species in 1984, little research has been dedicated to the species&rsquo; reproductive ecology. My objectives were to (1) identify predators of white-tipped dove eggs and nestling, (2) determine how the predator community differs among land cover types, (3) examine the impact of vegetation and landscape variation in both citrus and woodland land cover types on nest survival, (4) examine the impact of temporal variation on nest survival, (5) provide information on general nest ecology that is currently lacking, (6) investigate movements of doves and examine feasibility of tracking and recapture using a GPS/VHF transmitters pilot study. During the summers of 2015 and 2016, I conducted nest searches in citrus and woodland sites in Hidalgo County, Texas. I placed real-time, infrared emitting camera systems on a subset of nests to monitor predation. I also trapped, banded, and placed backpack transmitters on doves in Estero Llano Grande State Park (ELGSP) In the 2 years, I located 63 dove nests, 34 in citrus and 29 in woodland. I placed camera systems on 33 nests and identified 9 species of nest predator. Green jays (<i>Cyanocorax incas</i>) were our most common nest predator, accounting for 10 of 28 predation events. Other predators were crested caracara (<i>Caracara cheriway</i>), Harris&rsquo;s hawk (<i>Parabuteo unicinctus</i>), great-tailed grackle (<i>Quisicalus mexicanus</i>), tawny crazy ant (<i> Nylanderia fulva</i>), rat (<i>Rattus</i> spp.), opossum (<i> Didelphis virginiana</i>), house cat (<i>Felis catus</i>), and Texas indigo snake (<i>Drymarchon melanurus erebennus</i>). Based on AIC candidate model selection, I identified nest stage as the best predictor of daily nest survival rate across both land cover types. By separating land covers for a second step to model selection, I identified different environmental variables as predictors of daily survival rate in each land cover type. In the woodland site, my null model was most important, indicating that no measured variables were important for predicting nest survival. In citrus, canopy cover was the top model. In citrus, a diverse predator community due to heavy human disturbance may have increased the importance of canopy cover and other concealment variables for nest survival. The different predator communities they encounter in the two land cover types that they nest in prioritize much different environmental conditions for nest survival.</p>
4

Development of a water conservation strategy for Al Qasseem Province, Saudi Arabia.

Shoaibi, Abdullah Mohammed al- , January 1990 (has links) (PDF)
Thesis (M. S. - Renewable Natural Resources)--University of Arizona, 1990. / Includes bibliographical references (leaves 61-62).
5

The Trophic and Spatial Ecology of the Southern Flying Squirrel (Glaucomys volans) and Non-lethal Deterrent Methods

Meyer, Robert Timothy 18 May 2018 (has links)
<p> Southern flying squirrels (SFS; <i>Glaucomys volans</i>) are known kleptoparasites on the endangered red-cockaded woodpecker&rsquo;s (RCW; <i> Picoides borealis</i>) cavities and cost land managers time and money to control, and the ecology of SFS in habitats managed for RCWs is poorly understood. This study is designed to obtain a better understanding of the general ecology of SFSs surrounding RCW habitat and provide possible non-lethal deterrent methods to prevent harmful interactions between SFSs and RCWs. Spatially-explicit capture-recapture showed generally higher SFS densities and habitat associations outside of RCW cluster partitions. Stable isotope analysis of SFS diets across Mississippi and Alabama revealed a narrow dietary breath relative to food items, thus habitat management may still be viable option to control SFSs. Lastly, investigation of odor deterrents resulted in the greatest avoidance of cavities containing gray rat snake (<i>Pantherophis spiloides </i>) feces and warrants further investigation.</p><p>
6

Identifying critical fish habitat and long-term trends in fish abundances in the Hudson River estuary

O'Connor, Megan P 01 January 2010 (has links)
The Hudson River estuary (HRE) is a well monitored aquatic resource and much secondary data exist for this system. We developed two objectives based on accessible HRE aquatic data. The first objective was to determine if changes in HRE fish community over the time period (1974 to 2005) years are correlated to local and regional climate. We addressed this objective by employing a multivariate statistical approach. We confirmed that the HRE fish community structure has changed over the time period (1974 to 2005). These changes are correlated with local hydrology (freshwater flow and water temperature) and regional climate (Atlantic Multidecadal Oscillation or AMO and North Atlantic Oscillation or NAO). We found that abundances of striped bass larval stages are positively correlated with high freshwater flows and juvenile shad abundances are negatively correlated with the AMO or warmer sea surface temperatures (SST). This finding suggests that climate-related variability affects HRE juvenile shad abundances and current management strategies for this declining species should include the implications of climate change. The second objective was to examine whether factors such as sediment type, water characteristics and distance to nearest submerged aquatic vegetation (SAV) beds affect the occurrence or presence/absence of juvenile American shad (Alosa sapidissima) and juvenile striped bass ( Morone saxatilis) in the HRE during the fall. We addressed this objective by applying geostatistics and general linear mixed effects models. We found the probability of presence for both species were commonly driven by spatial dependence or river mile, Julian day and salinity. Our results include maps depicting probability of occurrence (or presence) for both species throughout the HRE. We found the highest predicted probabilities of juvenile American shad presence are found in the Upper HRE. Conversely, highest predicted probabilities of juvenile striped bass presence are found in the Lower HRE. Habitat partitioning between these two species is present during the fall in this system but the mechanism is unclear. Future studies could address a possible predator-prey or competitive relationship between juvenile American shad and juvenile striped bass.
7

Roosting, site fidelity, and food sources of urban gulls in massachusetts: Implications for protecting public water supplies

Clark, Daniel E 01 January 2014 (has links)
Anyone who has spent time in coastal New England has seen gulls flying overhead and heard their familiar sound; gulls may be one of the most recognizable birds in the world. There are over 50 species of gulls worldwide, and many of them are closely associated with human development or activities. In Massachusetts, there are several common gull species including herring (Larus argentatus), great black-back (Larus marinus), laughing (Leucophaeus atricilla), and ring-billed (Larus delawarensis). While coastal encounters with gulls are ubiquitous, gulls can also be found inland, and ring-billed and herring gulls are now a common sight at lakes, parks, and commercial parking lots dozens or hundreds of kilometers from the ocean. This inland population of gulls presents unique challenges and exciting research opportunities. Because they are often closely associated with human activity, concentrations of inland gulls can lead to potential water quality concerns (when large roosts form on public water supply reservoirs), airplane hazards (when groups of gulls concentrate near airports or flight paths), or disease transmission (when gulls forage at landfills or waste water treatment plants then visit areas with people). In the following chapters I explore various aspects of inland gull ecology during the non-breeding season. In chapter 1, I review the concept of philopatry in birds and discuss ways to assess site faithful behavior. In Chapters 2 and 3, I explore some of the ecological aspects of inland gulls. Chapter 2 examines the site fidelity of gulls to their wintering areas and my results suggest that gulls exhibit high winter-site fidelity but variable site persistence during the winter season. Chapter 3 explores roost site selection throughout the year and models roost selection in Massachusetts. My results indicate that ring-billed gulls prefer freshwater roosts, while herring gulls use saltwater roosts more often. In Massachusetts, both herring and ring-billed gulls select inland freshwater roosts based on the size of the water body and proximity to their last daytime location. In Chapter 4, I detail the results of an experimental study trying to reduce the amount of anthropogenic food available to gulls at inland parking lots. Ring-billed gulls were the most common gull found in parking lots, and my educational approach to reduce feedings had mixed results; education seemed to reduce the number of feedings in some cases, but the number of gulls in each parking lot was not affected. In Chapters 5 and 6, I detail some applied management techniques. Chapter 5 discusses efforts to exclude gulls from a waste water treatment plant in central Massachusetts. Overhead stainless-steel wires were completely effective at preventing gulls from using structures at the treatment plant. Chapter 6 describes an innovative technique that was used to efficiently and effectively catch gulls during winter in highly urbanized environments. I captured over 1000 gulls using a net launcher in various parking lots and other urban areas.
8

The movements, habitat use, and population assessment of western pond turtles (Actinemys marmorata) in a Southern California seasonal wetland

Nerhus, Barry S., Jr. 03 June 2016 (has links)
<p> This study investigates the population dynamics, movements, and habitat use of a population of western pond turtles in Orange County, California from 2008-2012 using radio telemetry and mark-recapture data. Western pond turtles have been thought to be declining throughout their range. However, few studies have documented their status in southern California, where urbanization has changed the landscape drastically in recent decades. I individually marked 236 pond turtles using hoop-net funnel traps and estimated the population size at 308 individuals, which is the largest estimate reported in southern California. Mean capture per unit effort was 5.03&plusmn;0.87. Mean female carapace length (CL) (142&plusmn;14mm) was not significantly larger than males (139&plusmn;14 mm). I also documented 20 nest and 9 estivation locations. Mean distances included 176 &plusmn;130.80 meters (m) and 91&plusmn;58.6 m. These data identify the population demography, which can be a metric of population stability. Other known populations need to be estimated to determine their regional status.</p>
9

Population Dynamics of Northern Cardinal and Carolina Wren in an Urban Forest Fragment| Safe Refuge or Ecological Trap?

Karmacharya, Binab 28 January 2016 (has links)
<p> Conserving bird populations in urban landscapes often depends on interactions between extinction, recolonization, and survival in remnant habitat patches such as small nature preserves. Thus, determining the ecological value of small nature preserves to birds is a necessary step towards an informed conservation strategy. As such, I conducted a year round capture-mark-recapture study from April 2010 to March 2014 to examine population dynamics of Northern Cardinals (<i>Cardinalis cardinalis</i>) and Carolina Wrens (<i> Thryothorus ludovicianus</i>) in a 41.7-ha nature preserve embedded in an urban matrix. More specifically, we examined variation in survival, recruitment, and realized population growth rates relative to year, season, sex, age, and wing length (as a proxy for body size) to investigate attributes that affect individual survival and to assess whether the reserve served as a population source or sink. The overall annual apparent survival rate of Northern Cardinals (0.520 &plusmn; SE 0.050) was higher than that of the Carolina Wrens (0.349 &plusmn; 0.050), and estimates in both species were similar to regional baseline estimates. The survival rates for adults were significantly higher than for immatures in both species, with body size having a positive influence on survival. Seasonal variation in survivorship was evident only in Northern Cardinals, being highest in the winter and lowest during the breeding season. Average annual population growth rate was slightly greater than 1.0 for both species, indicating stable or perhaps modestly increasing populations. These results represent the first published full annual cycle estimates of survival and population growth relative to age, sex, and body size for non-migratory passerines. Our results suggest that urban forests can provide the necessary resources to sustain growing populations of locally common birds. Furthermore, our demographic estimates derived from two healthy bird populations can serve as target values for other species of conservation concern within human-modified landscapes. </p>
10

Environmental drivers of deer population dynamics and spatial selection in southeast Alaska

Gilbert, Sophie L. 08 October 2015 (has links)
<p> The coastal temperate rainforest is one of the rarest ecosystems in the world, and a major portion of the global total is found in Southeast Alaska. In this ecosystem, Sitka black-tailed deer are the dominant large herbivore, influencing large carnivores that prey on deer such as wolves and bears, as well as plant species and communities through browsing. In addition, deer play an important economic and cultural role for humans in Southeast Alaska, making up the large majority of terrestrial subsistence protein harvested each year as well as providing the backbone of a thriving tourism industry built around sport hunting. Given the importance of deer in this system, there remain a surprisingly large number of key gaps in our knowledge of deer ecology in Southeast Alaska. </p><p> These knowledge gaps are potentially troubling in light of ongoing industrial timber-harvest across the region, which greatly alters habitat characteristics and value to wildlife. This dissertation research project was undertaken with the aim of filling several connected needs for further understanding deer ecology, specifically 1) patterns of reproduction and fawn survival, 2) population dynamics in response to environmental variability, and the underlying drivers of spatial selection during 3) reproduction and 4) winter. To fill these knowledge gaps, I developed robust statistical tools for estimating rates of fawn survival, and found that fawns must be captured at birth, rather than within several days of birth, in order to produce unbiased estimates because highly vulnerable individuals died quickly and were thus absent from the latter sample. I then use this robust approach to estimate vital rates, including fawn survival in winter and summer, and developed a model of population dynamics for deer. I found that winter weather had the strongest influence on population dynamics, via reduced over-winter fawn survival, with mass at birth and gender ratio of fawns important secondary drivers. </p><p> To better understand deer-habitat relationships, I examined both summer and winter habitat selection patterns by female deer. Using summer-only data, I asked how reproductive female deer balance wolf and bear predation risk against access to forage over time. Predation risks and forage were strong drivers of deer spatial selection during summer, but reproductive period and time within reproductive period determined deer reaction to these drivers. To ensure adequate reproductive habitat for deer, areas with low predation risk and high forage should be conserved. Focusing on winter, I evaluated deer spatial selection during winter as a response to snow depth, vegetation classes, forage, and landscape features. I allowed daily snow depth measures to interact with selection of other covariates, and found strong support for deer avoidance of deep snow, as well as changes in deer selection of old-growth and second-growth habitats and landscape features with increasing snow depth. Collectively, this dissertation greatly improves our understanding of deer ecology in Alaska, and suggests habitat management actions that will help ensure resilient deer populations in the future.</p>

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