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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

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
7

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.
8

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.
9

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
10

ACOUSTIC TEMPORAL VARIATION, CALL ORDER, AND TRAVEL IN RESPONSE TO ANTHROPOGENIC NOISE IN WILD SIAMANG (SYMPHALANGUS SYNDACTYLUS)

D'Agostino, Justin 01 June 2021 (has links) (PDF)
Communication is a behavioral strategy used by species in the competition for survival and reproduction. Animals produce signals that are sent to receivers and occasionally transmit information that can be beneficial in a variety of contexts including avoiding predators, locating food resources, and maintaining the pair bond between partners. Researchers are interested in if auditory signals are variable and if the variability is biologically meaningful to receivers. Some species, such as siamang, sing duets as their form of acoustic communication and these duets have been studied for a variety of purposes such as investigating their structure, variability, and functionality. Siamang are a species of gibbon that combine a finite number of call units into structurally complex sequences in rule-governed ways, hereby conveying different contextual situations. Some wild gibbon species have demonstrated variation in the temporal structure of their duets and the distinctiveness in acoustic timing is unique enough for researchers to distinguish among individuals and groups based on their duet contributions. The process of coordinating and producing a uniquely timed duet could function in relation to the formation and maintenance of the pair bond. This dissertation analyzed the temporal variation and call order of wild siamang (Symphalangus syndactylus) duets that are comprised of four distinct sequences comprised of several note types. Previous research has provided detailed descriptions of captive siamang duets that include category descriptions of four call types: grunting, introduction, interlude, and great call. While these descriptions provide a general understanding of the structure of siamang duets, they can be confusing and difficult to study empirically due to their arbitrary nature. For instance, the siamang great call has been described as occurring in over 30 variants and in stable, or typical, and unstable, or atypical forms. The stable or typical form of the great call has been described to occur only after the male’s first bitonal scream. This previous research did not measure the timing of sequences through entire duets or conduct individual note analyses. Also, the most detailed investigations of siamang duets were conducted with captive animals and therefore wild siamang duets have not been quantitatively analyzed. This dissertation research measures the temporal variation of wild siamang duet call types, and the call order of individual notes in the US-II phrase. The findings will provide a more objective description of the siamang duet as well as determine if it has a more stereotyped or flexible nature. Also, in the wake of globalization, duets and other behaviors (such as travel) could be sensitive to anthropogenic disturbances. So, I am interested in how wild siamang might be impacted by human presence. The three main objectives of this dissertation are: 1) document the temporal variation in the call types of wild siamang; 2) document variation in the call order of wild siamang US-II phrases; and 3) document how wild siamang travel is impacted by anthropogenic noise. The study was conducted at 4 remote field sites in northern Sumatra, Indonesia from August 2017 through May 2018. With the assistance of a research team, I recorded acoustic and behavioral data from 10 siamang groups and two individual females. I collected acoustic data using a combination of autonomous recording units and handheld recording devices while following the study subjects on foot. I marked GPS points during behavioral scans and conducted experimentally induced noise playback experiments. I analyzed the audio data with the software program Raven Pro 1.6 and spectrograms were produced with a 512-point (11.6 ms) Hann window (3 dB bandwidth = 135 Hz), with 50% overlap and a 512-point DFT, yielding time and frequency measurement precision of 2.9 ms and 43.1 Hz. I conducted statistical testing in R Studio Version 1.3.959 in conjunction with the statistics lab at Southern Illinois University. In Chapter 3, I performed multilevel regression analysis in the form of a Generalized Linear Mixed Model (GLMM) in order to investigate temporal variation the time spent singing call types (grunting, introduction, interlude, and great call) accounting for differences between songs, groups, and field sites. I used a Bayesian hierarchical model to avoid calculating estimates using data with repeated and imbalanced sampling, and explicitly model variation within individuals, between songs, between groups, and field sites. In Chapter 4, I used the Levenshtein Distance (LD) method for investigating structural variation in the call order of US-II phrases in the siamang duet. The LD method is a quantitative technique for measuring the similarity of sequences and to quantify the differences between strings of data. In Chapter 5, I used the Friedman test to compare the means of distances traveled in 5-minute intervals in the following conditions: pre-playback, cicada (control), traffic, jackhammer, and music. I used post hoc tests with Bonferroni correction to analyze the pairwise comparisons of the five experimental conditions. Overall, the results suggest support of previous studies on the variability of the gibbon duet and animal travel in response to noise. In Chapter 3, I found some temporal variation in call types to exist at all levels of the modeling but only statistically significant when comparing the field sites of Ketambe and Kutapanjang. Relating to the functionality of total call duration, I did not find significant differences in the behavioral categories before or after any of the calls regardless of their total duration. In Chapter 4, I found US-II phrases are not as stereotyped as previous descriptions have suggested. The mean LD distances were higher than those compared by other duetting primates. Also, the results from one-way ANOVA and Games-Howell Post Hoc Testing showed significant mean differences between groups. In Chapter 5, I found siamang are impacted by noise as they traveled further after the anthropogenic noise playback experiments compared to pre-playback travel. However, the pairwise comparisons were not statistically significant and therefore I could not determine which noise condition caused the change in travel distance. Collectively, the results of this dissertation suggest that there is considerable variability in both wild siamang call types and call order in a previously described stereotyped phrase, and that wild siamang travel away is impacted by introduced anthropogenic noise. What this contributes to the field of vocalization studies is further support that precise measurement of song parameters gives a better understanding of song structure than somewhat arbitrary written descriptions. It is important to have descriptions of notes produced in songs, but to understand how those notes relate to each other, an individual note analysis and rigorous statistical methodology is necessary. The variation found in this dissertation could be due to the unique siamang response to their partner’s timing in the process of forming the pair bond. But as the siamang duet is thought to have multiple functions, the temporal variation could also be transmitting other information such as individual and group identity while functioning in territorial defense. In addition, anthropogenic noise caused the animals to change their travel behavior and this suggests it could be harmful if faced on a regular basis. Anthropogenic noise can be detrimental if it occurs in home ranges of species that are territorial and facing shrinking habitats due to continued human encroachment. In order to understand if these findings are biologically meaningful and to have firmer conclusions, future long-term studies will need a larger data set over longer periods of time. It is also important to have a larger data set and compare more siamang groups that live in various noise levels and measure variables such as caloric intake, daily travel, copulations, and number of offspring.

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