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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

The effects of oil and gas infrastructure noise on alarm communication in Savannah sparrows (Passerculus sandwichensis)

Antze, Bridget 31 August 2016 (has links)
Anthropogenic noise may interfere with avian acoustic communication, however some species alter the structure of vocalizations, to improve transmission in noise. Here, I conducted playback experiments to determine whether compressor stations, generator or grid-powered screw pump oil wells, and overall ambient noise levels affected responses of Savannah sparrows (Passerculus sandwichensis) to conspecific alarm calls at their nests. I also measured the structure of alarm calls, to determine whether Savannah sparrows altered vocalizations in noise. On control sites, Savannah sparrows responded to alarm calls by delaying provisioning visits. At compressor station sites, the loudest infrastructure treatment, they showed less of a delay. Close to compressor stations, Savannah sparrows lowered the frequency and increased the bandwidth of alarm calls. These findings suggest the compressor stations may interfere with anti-predator communication, but that Savannah sparrows can alter the structure of alarm calls at these sites, perhaps mitigating some effects of noise. / October 2016
2

Impacts of Vessel Noise Perturbations on the Resident Sperm Whale Population in the Gulf of Mexico

Azzara, Alyson 2012 May 1900 (has links)
The Gulf of Mexico is home to two of the world?s ten busiest ports by cargo volume, the Port of New Orleans and the Port of Houston; and in 2008, these ports hosted a combined 14,000 ships, a number which is likely only to increase. Past research shows that this increase in shipping worldwide has historically lead to an increase in ambient noise level of 3-5dB per decade. Sperm whales in the Gulf of Mexico are considered a genetically distinct, resident population. They have a preference for the Louisiana-Mississippi Shelf region which directly overlaps with the entrance to the Mississippi and the Port of New Orleans. Disruptions from vessel noise could influence feeding and breeding patterns essential to the health of the stock. Data used in this analysis were collected continuously over 36 days in the summer of 2001 from bottom moored Navy Environmental Acoustic Recording System (EARS) buoys. Results showed a significant difference (P<0.05) in noise level between hours with ships passing and hours without. Metrics for 56 ship passages were analyzed to compare duration of ship passage with duration of maximum received level (MRL) during ship passage. Results of that analysis showed an average ship passage of 29 minutes with average MRL lasting 23% of the ship passage and an average increase of 40dB. Lastly, click counts were made with the Pamguard. Click counts for ship passages were completed for 35 min and 17.5 min before and after the estimated closest point of approach (CPA) for each ship. Results showed a 36% decrease in the number of detectable clicks as a ship approaches when comparing clicks detected at intervals of both 35 minutes before and 17 minutes before the CPA; additionally, 22% fewer clicks were counted 30 min after the ship than 30 min before (results significant at the P=0.01 level). These results indicate a potential change in sperm whale behavior when exposed to large class size vessel traffic (e.g. tankers and container ships) from major shipping lanes. Recommendations for addressing this issue are discussed.
3

Impacts of Anthropogenic Noise on Aquatic Invertebrates in Wetland Habitats

Hopson, Adrienne M. 31 July 2019 (has links)
No description available.
4

Influences of Anthropogenic Noise on Flight Initiation Distance, Foraging Behavior, and Feeder Community Structure of Wild Birds

Petrelli, Alissa R 01 December 2017 (has links) (PDF)
Throughout the world, birds represent the primary type of wildlife that people experience on a daily basis. However, a growing body of evidence suggests that alterations to the acoustic environment can negatively affect birds as well as humans in a variety of ways, and altered acoustics from noise pollution has the potential to influence human interactions with wild birds. In this thesis, I investigated how anthropogenic noise impacts daily behavior as well as community structure of wild birds. In the first component of this thesis, I assessed the distance at which a bird initiates flight or escape behavior (i.e., flight initiation distance or FID) in varying acoustic conditions. I surveyed 12 songbird species from three foraging guilds, ground foragers, canopy gleaners, and hawking flycatchers, and I predicted FIDs to decrease, remain the same, and increase with noise exposure, respectively. Contrary to expectations, the canopy gleaning and flycatching guilds exhibited mixed responses, with some species exhibiting unchanged FIDs with noise while others exhibited increased FIDs with noise. However, FIDs of all ground foraging species and one canopy gleaner decreased with noise levels. In the second component, I examined the feeding of wild birds, an increasingly popular recreational activity throughout North America that promotes increased sense of wellbeing by connecting people with wildlife and nature. I tested how experimental noise influences abundance, species richness, community structure and foraging behavior of songbirds at maintained bird feeders. By measuring activity levels of all species that utilized the feeders exposed to intervals of quiet and noisy conditions, I found noise to be a significant predictor of community turnover. Specifically, noise exposure resulted in increased feeder activity for two species, and decreased activity for one species. I also confirmed previous research conducted in the laboratory indicating white-crowned sparrows decrease their foraging rate under noise conditions, presumably as a trade off with visual vigilance. Considering the interactions of humans and wild birds, the results from my two thesis components indicate that the acoustic environment can play a role in how species of different foraging guilds respond to birdwatchers and what species visit bird feeders.
5

Effects of Experimental Noise Exposure on Songbird Nesting Behaviors and Nest Success

Mulholland, Tracy I 01 August 2016 (has links) (PDF)
Anthropogenic noise is an increasingly prevalent global disturbance. Animals that rely on the acoustical environment, such as songbirds, are especially vulnerable to these sounds. Traffic noise, in particular, overlaps with the frequency range of songbirds, creating masking effects. We investigated the effects of chronic traffic noise on provisioning behaviors and breeding success of nesting western bluebirds (Sialia mexicana) and ash-throated flycatchers (Myiarchus cinerascens). Because anthropogenic noise exposure has the potential to interrupt parent-offspring communication and alter vigilance behaviors, we predicted that traffic noise would lead to changes in provisioning behaviors, such as fewer visits to the nest box, for each species. We also predicted the noise to negatively influence one or more metrics reflective of reproductive success, such as nest success, clutch size, number of nestlings or number of fledglings. Importantly, we were able to eliminate self-sorting among individuals with respect to noise and other possible effects of traffic, such as collisions and pollution, by experimentally introducing traffic noise into nest boxes after clutch initiation using playback systems. Our results indicate no effect of traffic noise on S. mexicana reproductive measures, despite seeing changes in provisioning behaviors suggestive of an increased stress response. However, M. cinerascens experienced fitness consequences from chronic anthropogenic noise exposure when combined with the effect of year. Despite equal clutch sizes to flycatchers in boxes with no noise exposure, noise-treated flycatcher nests experienced a reduction in hatching success and subsequent metrics, such as number of nestlings or fledglings relative to control boxes, during the first study year. The year in which we witnessed the decline in nest success for ash-throated treatment individuals coincided with a significant drought year, suggesting that combinations of multiple stressors lead to nest abandonment. In recording provisioning behaviors during the fledgling stage, no difference in provisioning was found between treatment and control ash-throated flycatcher nests. We contrast these species-specific responses to recent observational work on both species in New Mexico and other studies that have examined fitness consequences of noise. Lastly, we stress the importance of these findings in addressing current conservation practices of nest box placement with respect to roads.
6

Hydroacoustic Parametric Study of Pile Driving-Induced Anthropogenic Sound

Wojciechowski, Shannon 04 June 2024 (has links)
Anthropogenic sound in Florida's waters and coastal waterways is most commonly caused by overwater development, marine traffic, and military activity. Overwater construction has increased over the years as a result of aging infrastructure and rising expansions around the United States, including more than forty US Naval facilities containing tens of thousands of feet of pier. Construction methodology, such as pile driving, has risen in shallow waters to build structures such as bridges, piers, and wind farms, with significant consequences for marine life and the environment. More precisely, pile driving activities generate significant decibel levels in the surrounding marine environment. Measurements taken from hydrophones placed in the water near the construction site indicate that the high sound pressure levels produced may be harmful to marine life and the environment. As a result, standards have been established to help alleviate and decrease the possible harm that high decibel sound levels may produce. However, these additional steps increase the overall cost of the construction project. This thesis focuses on replicating the pile driving process using finite element modeling to hydroacoustic parametric study of pile driving-induced anthropogenic sound in neighboring Florida seas, as well as the possible environmental impact of the state's numerous naval base piers. The modeling predictions can then be used to identify the distance from the pile at which marine life and the environment are no longer adversely affected. In addition, computer modeling can reduce construction costs when compared to on-site sensors and monitoring. / Master of Science / Over recent years there has been an increase in the amount of manmade noise in Florida and its coastal waterways due to overwater construction, marine traffic, and military activities. Pile driving construction has increased in shallow waters to build infrastructure, which includes bridges, piers, and wind farms, resulting in a negative impact for marine life and the environment. Federal agencies have established guidelines to ease the harmful effects construction has on marine life and the environment. However, there is concern that these recent guidelines may not properly consider all the geometric and hydrographic variables of manmade noise that affect the high sound exposure levels during pile driving. With a more accurate understanding of the sound generation produced from pile driving, predictions can assist with sound mitigation to ensure less harm to the marine life and environment. In turn, construction companies and government agencies informed with this enhanced understanding can make better decisions that lead to fewer (or possibly eliminate) transmission loss discrepancies and costly noise mitigation measures. Consideration of the marine environment is one of the United States Navy's top priorities with naval stations located throughout the State of Florida that possess thousands of feet of waterfront structures, including piers, requiring routine maintenance and construction. This thesis models the pile driving process through finite element modeling in COMSOL Multiphysics computer software, testing the various parameters that Florida waters may encounter with pile driving on the surrounding coast as well as naval bases.
7

The Effects of Conventional Oil Wells and Associated Infrastructure on the Abundances of Five Grassland Songbird Species in Alberta’s Mixed-grass Prairie

Nenninger, Heather R. 31 August 2016 (has links)
Although grassland bird populations have steadily declined, little research has examined the effect of oil infrastructure on abundances of grassland songbirds. Even less research has identified mechanisms that explain observed effects. To evaluate this, I sampled abundance of 5 songbird species at oil well sites with different pump mechanisms, power sources, and activity levels; I also evaluated the effects of perch and road density and exotic vegetation, all of which are associated with oil development. Both Baird’s sparrows (Ammodramus bairdii) and Sprague’s pipits (Anthus spragueii) had lower abundances at all sites that contained oil infrastructure. The other 3 species, chestnut-collared longspurs (Calcarius ornatus), western meadowlarks (Sturnella neglecta), and Savannah sparrows (Passerculus sandwichensis), were relatively unaffected by oil wells, linear features, or exotic vegetation. Given that oil well sites negatively affected two species of concern, more research is needed to determine mitigation strategies. / October 2016
8

Impacts of anthropogenic noise on behaviour, development and fitness of fishes and invertebrates / Étude des bruits anthropiques sur le comportement, le développement et le fitness des poissons et des invertébrés

Nedelec, Sophie 17 August 2015 (has links)
Dans la première partie de ma thèse, je fournis un programme informatique qui permet aux utilisateurs de déterminer dans quelles circonstances ils doivent mesurer le mouvement des particules. J’explique comment ces mesures peuvent être effectuées et fournissent un programme pour analyser ce type de données. La partie principale de ma thèse comprend des expériences portant sur l'impact de l'exposition répétée au bruit du trafic, la source anthropique la plus courante de bruit dans l'environnement marin, sur les poissons et les invertébrés pendant leur développement. Je démontre qu’une variété de comportements a été touchée par le bruit. J’ai aussi trouvé que le bruit prévisible peut conduire à des impacts différents sur le développement par rapport au bruit imprévisible, mais que certaines espèces de poissons peuvent être en mesure de s'habituer au bruit du trafic, tandis que d'autres non. En outre, je trouve que le développement et la survie des limaces de mer peuvent être impactés négativement par le bruit des bateaux. Les poissons et les invertébrés constituent une source de nourriture vitale pour des millions de personnes et constituent des liens essentiels dans de nombreux réseaux trophiques. L'étude de leur comportement, de développement et de remise en forme peut nous donner un aperçu des impacts de la population et le niveau de bruit de la communauté qui sont pertinents pour la survie des espèces et l'évolution. Le développement de certaines des nouvelles idées et techniques abordées dans cette thèse nous permettra de faire progresser ce domaine vital de la recherche. / As the first part of my thesis, I provide a computer program which allows users to determine under what circumstances they should measure particle motion; I explain how these measurements can be made and provide a program for analysing this type of data. The main part of my thesis comprises experiments investigating the impact of repeated exposure to traffic noise, the most common anthropogenic source of noise in the marine environment, on fishes and invertebrates during development. In all three chapters involving experiments on fish in tanks and in the field, I found that a variety of behaviours were impacted by traffic noise playback. I also found that predictable noise can lead to different impacts on development compared to unpredictable noise, but that some species of fish may be able to habituate to traffic noise, while others suffer lower survival. Further, I found that the development and survival of seahares can be negatively impacted by traffic-noise playback. Fishes and invertebrates provide a vital food source to millions of people and form crucial links in many food webs; studying their behaviour, development and fitness can give us an insight into population and community level impacts of noise that are relevant to species survival and evolution. Developing some of the novel ideas and techniques discussed in this thesis will enable us to advance this vital area of research.
9

Marine mammal behavior response to sonars, a review

Linderhed, Anna January 2013 (has links)
During the last decades the problems caused by anthropogenic sound and noise in oceans have been recognized in public, by governments, and military. With the use of active sonar, different choices can be made to minimize the risk of damaging or disturbing marine mammals. For this purpose knowledge of sonar disturbance is crucial. There are methods for time or area planning, i.e. when and where to use active sonars, to avoid marine mammals. The purpose of this work is to find information in literature on marine mammal behaviour reactions to the sound of sonar pings, and to evaluate which of two different behavioural models used in risk assessment programs, the “varying response” model and the “avoidance” model, is more correct to use. Main focus is on sonars and marine mammals residing in Sweden, i.e. the harbour porpoise, grey seal, harbour seal and ringed seal. Behavioral results from other research areas such as bycatch, environmental, and strandings, together with other sound sources than sonars and other species, provide a broader picture of the situation in noisy oceans. For the harbor porpoise the “avoidance” model works well. It is a very shy species, which flees fast and far when it comes in contact with new things. With the seals however the “avoidance” model is probably less good, since their responses to sonar differ rather much. Hence, for these taxa we recommend to use the “various” model that takes into account such varying responses.
10

Listening to whales: tying acoustics to ecology

Burnham, Rianna Elizabeth 04 December 2018 (has links)
The acoustic sense is vital to all life processes for whales. It defines their ‘active space’, and the extent and nature of interactions with their surroundings. Yet, we are still learning the basics of most species’ acoustic behaviours and vocal repertoires. The ecology of gray whales (Eschrichtius robustus) is well known, however vocal behaviours are not well described outside of breeding lagoons. Bottom-stationed acoustic monitoring devices were deployed in Clayoquot Sound, west coast Vancouver Island to explore acoustics use outside of these areas. During migration the use of low frequency moan calls are prevalent, perhaps for group cohesion, with lead whales guiding followers. During the summer more inter-group calls (knocks, upsweeps) are employed. Here I explored the use of ‘motherese’ calls between cow-calf pairs, and how this may mirror the weaning process. Photoperiod, increased ambient noise, threat perception, and vessel and aircraft presence elicited acoustic responses. Calling was also altered by social, behavioural, and physiological state. These results begin to show gray whales to be acoustically sensitive, with highly nuanced vocalising behaviours. Acoustic methods afford monitoring at times and in places that would otherwise be impossible, and lends themselves to the study of rare or cryptic species. Ocean gliders with passive acoustic capacity were used to explore deep-coastal and shelf-break waters for large whale species. Humpback whales (Megaptera novaeangliae) were common on the shelf, whereas calls from fin (Balaenoptera physalus), blue (Balaenoptera musculus), sperm (Physeter macrocephalus), and possibly sei whales (Balaenoptera borealis) were heard in more offshore locations. Concurrent habitat data steams help establish area use and importance to these species. The surveys focus on submarine canyons that are thought to aggregate prey. Calls denote whale presence, whereas call type may suggest behaviour and habitat use. Calls described for feeding and breeding were heard for fin and blue whales, with distinct temporal distribution. Acoustic techniques complement other ecological methods and can fill existing knowledge gaps in whale life histories. It can also help quantify the effect of human activities on whale populations and ocean soundscapes. These findings will inform management actions. I provide examples of management links to acoustic-ecological research. / Graduate

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