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1
Fleming, Kimberly Hoover. "The social structure, behavior, and occurrence of bottlenose dolphins in relation to shrimp trawlers in Southport, North Carolina /." Electronic version (PDF), 2004. http://dl.uncw.edu/etd/2004/flemingk/kimfleming.pdf.
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Sloan, Peggy E. "Residency patterns, seasonality and habitat use among bottlenose dolphins, Tursiops truncatus, in the Cape Romain National Wildlife Refuge, SC /." Electronic version (PDF), 2006. http://dl.uncw.edu/etd/2006/sloanp/peggysloan.pdf.
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Esch, H. Carter. "Whistles as potential indicators of stress in bottlenose dolphins (Tursiops truncatus) /." Electronic version (PDF), 2006. http://dl.uncw.edu/etd/2006/eschh/hcarteresch.pdf.
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Krützen, Michael Christian. "Molecular relatedness, paternity and male alliances in bottlenose dolphins (Tursiops sp.) in Shark Bay, Western Australia /." Connect to this title online, 2002. http://www.library.unsw.edu.au/~thesis/adt-NUN/public/adt-NUN20030128.113021/index.html.
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Balmer, Brian C. "Seasonal abundance, site-fidelity, and utilization areas of bottlenose dolphins in St. Joseph Bay, Florida /." Electronic version (PDF), 2007. http://dl.uncw.edu/etd/2007-1/balmerb/brianbalmer.pdf.
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Fougères, Erin M. "Thermoregulation in bottlenose dolphins (Tursiops truncatus)." View electronic thesis, 2008. http://dl.uncw.edu/etd/2008-1/r3/fougerese/erinfougeres.pdf.
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Silva, Mónica Almeida e. "Population biology of bottlenose dolphins in the Azores archipelago." St Andrews : University of St Andrews thesis, 2007. https://research-repository.st-andrews.ac.uk/handle/10023/215.
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Harper, Cally. "Morphology of the melon and its tendinous connections to the facial muscles in bottlenose dolphins (Tursiops truncatus) /." Electronic version (PDF), 2007. http://dl.uncw.edu/etd/2007-1/harperc/callyharper.pdf.
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DeLong, Caroline M. "Object-centered representations in echolocating dolphins evidence from acoustic analyses of object echoes and a human listening study /." Thesis, University of Hawaii at Manoa, 2003. http://proquest.umi.com/pqdweb?index=0&did=765084621&SrchMode=1&sid=7&Fmt=2&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1233101570&clientId=23440.
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Fortuna, Caterina Maria. "Ecology and conservation of bottlenose dolphins (Tursiops truncatus) in the north-eastern Adriatic Sea." Thesis, St Andrews, 2007. http://hdl.handle.net/10023/157.
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Finn, Hugh C. "Conservation biology of bottlenose dolphins (Tursiops sp.) in Perth metropolitan waters." Access via Murdoch University Digital Theses Project, 2005. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20051103.135358.
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Barbieri, Michelle Marie. "Physiological and behavioral thermoregulation in bottlenose dolphins (Tursiops truncatus) in Sarasota, Florida /." Electronic version (PDF), 2005. http://dl.uncw.edu/etd/2005/barbierim/michellebarbieri.pdf.
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Brieze, Ilze. "Behavioural ecology of bottlenose dolphins (Tursiops sp.) and interactions with humans in Southeast Queensland, Australia /." [St. Lucia, Qld.], 2003. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17014.pdf.
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Wang, John Yu-Chao. "The classification of sympatric forms of bottlenose dolphins (genus Tursiops) in Chinese waters." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0020/NQ51021.pdf.
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Toland, Ronald W. "High frequency components in bottlenose dolphin echolocation signals /." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1998. http://handle.dtic.mil/100.2/ADA354939.
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Thesis (M.S. in Engineering Acoustics) Naval Postgraduate School, September 1998."september 1998." Thesis advisor(s): Thomas G. Muir, Steven R. Baker. Includes bibliographical references (p. 58). Also available online.
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Toland, Ronald W. Jr. "High frequency components in bottlenose dolphin echolocation signals." Thesis, Monterey, California. Naval Postgraduate School, 1998. http://hdl.handle.net/10945/8469.
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Approved for public release; distribution is unlimitedThe research described in this thesis is a continuation of work started by the Applied Research Laboratories of the University of Texas at Austin into the analysis of biosonar signals. Experiments conducted in 1997 on two species of small toothed whales found these species to emit significant high frequency signal components, extending to as high as 400 to 500 kHz. To assess the importance of these high frequencies in dolphin echolocation and target identification, experiments were performed in which an acoustic filter, used to suppress the high frequencies, was placed between a dolphin and a target. Insertion Loss and Reflection Loss measurements performed on 1/4" thick and 1/2" thick Sound Absorbing Filters (SOAB) demonstrated their effectiveness at absorbing high frequencies above 150 kHz, with little reflectivity. The results from one echolocation experiment, with one dolphin, showed the animal's ability to classify targets was essentially unaffected by the insertion of the filters. Analysis of the dolphin's echolocation signals showed the animal definitely compensating for the filters, by increasing its sound energy output, especially at frequencies above 100 kHz. It is anticipated that this initial experiment will lead to future research in explaining the existence of these high frequency echolocation components.
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Dunkin, Robin C. "Ontogenetic changes in the thermal and buoyant properties of Atlantic Bottlenose Dolphin (Tursiops truncatus) blubber /." Electronic version (PDF), 2004. http://dl.uncw.edu/etd/2004/dunkinr/robindunkin.pdf.
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Islas, Valentina. "Genetic characterisation and social structure of the East Scotland population of bottlenose dolphins (Tursiops truncatus)." Thesis, University of St Andrews, 2010. http://hdl.handle.net/10023/1002.
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The Eastern Scottish population of bottlenose dolphins (Tursiops truncatus) is the northernmost population of this species. The resident core of this population consists of 120 to 150 different individuals. This small size and its geographical isolation from other populations raises questions about its viability and whether the population has behavioural patterns that differ from those common to other populations of the same species. Microsatellite genetic diversity was low and mitochondrial DNA genetic diversity values were lowest in East Scotland compared to other populations worldwide and to neighbouring populations around UK waters. It has been well documented, from four different field sites worldwide, that male bottlenose dolphins form alliances with preferred male associates. These alliances can last for several years and the males involved show association coefficients similar to those of mothers and calves (0.8-1.0). These alliances appear to be of great importance in obtaining matings for the males. In the Eastern Scottish population males do not form alliances. No evidence of strong associations between individuals of either sex was found and there was no correlation between association and relatedness patterns. I suggest that the isolation and small size of the population together with reduced genetic diversity affects the pressure of kin selection for altruistic behaviours. There is no gain in competing or associating with close relatives for access to mates and it might be more important to avoid inbreeding by dispersing. Although evidence of gene flow between East Scotland and its neighbouring populations was not confirmed with Bayesian clustering analysis, a small set of individuals from Wales were found to be closely related to individuals from the East Coast of Scotland. In general the dynamics found in UK water populations resemble those of the Western North Atlantic with sympatric populations of coastal as well as pelagic individuals.
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Cole, Katharine Ruth. "Energetics in the Atlantic bottlenose dolphin, Tursiops truncatus Montagu." Thesis, University of Aberdeen, 1995. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU543518.
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Various aspects of energetics of the Atlantic bottlenose dolphin, Tursiops truncatus Montagu, were investigated, including the relationship between ventilation rate and behaviour, the structure of the breath, basal metabolic rate, and the cost of echolocation. An ethogram was defined through observation of a sub-group of seven dolphins, which proved to be representative for dolphins in captivity. Ventilation rates for the behaviours within the ethogram were measured using a stopwatch, and analysis of spoken and filmed commentaries, on the behaviour of 36 dolphins at five study sites. Ventilation rate was found to vary significantly with behaviour, and was used to estimate the relative costs for different behaviours. All the behaviours were assumed to be aerobic as there was no correlation between consecutive apnoeic periods, and there were no "carry-over" effects when dolphins changed behaviour. Swimming at approximately 1.5 m s-1 and 2 m -1s, incurred similar ventilation rates, and presumably costs, to stationary resting. Ventilation rate increased as speed increased, or when the dolphins swam at the surface. Dolphins spent the majority of time for which they were observed in the behaviours which incurred the lowest ventilation rates. Six ventilatory parameters were measured in 29 dolphins. These included expiration and inspiration duration, the time for which the blowhole was open, and the time spent at the surface. Mean breath duration (expiration + inspiration) was 0.860.16 s (n=2762). The duration of both expiration and inspiration could be varied, although inspiration was more flexible than expiration. Expiration time could be increased by reducing inspiration time or by extending the time the blowhole was open. Inspiration time had a significant influence on the time the blowhole was open and the time spent at the surface.
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Reddy, Kasturi. "The reproduction biology of four species of South African dolphins." Thesis, Rhodes University, 1996. http://hdl.handle.net/10962/d1005441.
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Seasonality of reproduction in common dolphins (Delphinus delphis), bottlenosed dolphins (Tursiops aduncus), striped dolphins (Stenella coeruleoalba) and humpbacked dolphins (Sousa chinensis) was examined using standard light microscope techniques. In the males four stages of testicular development could be identified. Individuals less than 2.26m in length and 105kg in mass had testes that contained small seminiferous tubules (0.048mm ± O.Olmm in diameter) and were classified either as juveniles (gonocytes present) or inactive (no gonocytes). Adults whose testes contained spermatozoa were said to be in late spermatogenesis while those whose testes contained no spermatids or spermatozoa were referred to as being in early spermatogenesis. In the males of D. delphis, T. aduncus and S. chinensis, late spermatogenesis occurred throughout the year and there was no significant difference in the monthly mean seminiferous tubule diameters (p > 0.05) within species. I conclude therefore that in these three species spermatogenesis is aseasonal. No conclusions about seasonality of spermatogenesis could be made for S. coeruleoalba owing to the small sample size. Large Graafian follicles occurred in the ovaries of all four species in most months of the year. However, the presence of Graafian follicles can not be taken as an indication of timing of reproduction since they may be remnants of follicles that have not yet degenerated. In D. delphis, T. aduncus and S. coeruleoalba luteal bodies (corpora albicans or corpora lutea) occurred in most months of the year. Active corpora lutea will be present in all months, in some members of the population, since gestation is approximately 12 months. The sperm structure of D. delphis was examined by scanning electron microscopy. The sperm of D. delphis is essentially similar to that described for two other species of Cetacea (Physeter catodon and Tursiops aduncus), having an ellipsoidally shaped head and a short mid-piece with nine mitochondria. The sperm dimensions for D. delphis were head length, 4.4pm; head width, 2.0pm and mid-piece length, 2.4pm. An analysis of foetal age in D. delphis showed that the majority of the foetuses were conceived in January with birth occurring the following summer (December), suggesting that reproduction is seasonal. Neonates of T. aduncus were found throughout the year suggesting aseasonal reproduction. Foetal material was not available for S. coeruleoalba and S. chinensis. Seasonality of reproduction in the four species of dolphins studied has been discussed in relation to feeding, migration and worldwide distribution of the species.
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van, Geel Catherina Francisca (Nienke). "Predator movements in complex geography : spatial distribution and temporal occurrence of low-density bottlenose dolphin communities off western Scotland." Thesis, University of the Highlands and Islands, 2016. https://pure.uhi.ac.uk/portal/en/studentthesis/predator-movements-in-complex-geography(f898982a-6509-4e73-9340-b0ad7463ae6d).html.
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The coastal waters off western Scotland are inhabited by two small under-studied common bottlenose dolphin (Tursiops truncatus) communities: the Inner Hebrides and the Sound of Barra (SoB) community. The region is considered for future developments for the marine renewables industry, which have the potential to negatively impact these communities; however the assessment of impacts and the development of plans to minimise these are currently hampered by a lack of knowledge about the dolphin's distribution and residency patterns, and spatial and temporal mobility. Using a variety of research methods (dedicated cetacean surveys and targeted photo-ID trips, acoustic monitoring and the collection of opportunistic photo-ID and sightings data from the general public) the current study examined local dolphin spatial and temporal mobility patterns by investigation of their spatial distribution and temporal occurrence. Collectively, the results revealed the presence of two socially and geographically separated (at least 2006-2013) resident communities which both demonstrated year-round presence and long-term site-fidelity, but maintained different ranging patterns. Long-term presence of individuals from the Inner Hebrides community dated back to 2001 and dolphins from this community ranged widely in nearshore waters throughout the entire currently known communal range, and practically used the entire range throughout the year. The SoB community, on the other hand, appeared to have a more restricted distribution, and appeared female-dominated. Summer censuses of the SoB community revealed annual estimates of ≤15 dolphins, with four individuals first identified in 1995, and at least eight calves born since 2005. Acoustic presence of dolphins in the SoB varied through the year, and in relation to the tidal and diel cycles. This study demonstrated that the integration of complementary methodological approaches is useful in investigating mobility patterns of low-density populations, and given the indications for social and spatial isolation, these communities should be managed independently.
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Stuby, Richard George. "A stochastic measure of similarity between dolphin signature whistles /." This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-03042009-040851/.
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Gridley, Teresa. "Geographic and species variation in bottlenose dolphin (Tursiops spp.) signature whistle types." Thesis, University of St Andrews, 2011. http://hdl.handle.net/10023/1910.
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Geographic variation in the whistle vocalisations of dolphins has previously been reported. However, most studies have focused on the whole whistle repertoire, with little attempt to classify sounds into biologically relevant categories. Common bottlenose dolphins (Tursiops truncatus) use individually distinctive signature whistles which are thought to help maintain contact between conspecifics at sea. These whistles may show a different kind of variation between populations than non-signature whistles. Here I investigate signature whistle use and variation in the two recognised species of bottlenose dolphins (T. truncatus and T. aduncus) from populations inhabiting the coastal waters of the North America, Scotland, South Africa, Tanzania, Japan, Australia and New Zealand, and one captive colony. I identified likely signature whistles (signature whistles types, SWTs) from acoustic recordings by combining two novel techniques: automated contour categorisation in ARTwarp (Deecke and Janik, 2006) and a specific bout analysis based on the timing of signature whistle production in T. truncatus termed SIGID (Janik et al. in press). Three ways of categorising the contours were tested and between 87 and 111 SWTs were identified in total. Repeated emissions of stereotyped contours were apparent in the repertoire of all T. aduncus populations using both automated and human observer categorisation, providing good evidence for signature whistle use in this species. There was significant inter-specific variation in the frequency parameters, looping patterns and duration of SWTs. Inflection points, duration and measures of SWT complexity showed high variation within populations, suggesting inter- and intra-individual modification of these parameters, perhaps to enhance identity encoding or convey motivational information. Using 328 bases of the mtDNA control region, I found high levels of population differentiation (FST and φST) within the genus Tursiops. These data do not support a link between mtDNA population differentiation and variability in call type. Instead, morphological variations at the species level, and learned differences at the population level, better explain the variation found.
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Hill, Mandy Lee. "Signature whistle productions, development, and perception in free-ranging bottlenose dolphins /." Electronic version (PDF), 2002. http://dl.uncw.edu/etd/2002/hillm/mandyhill.html.
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Boisseau, Oliver, and n/a. "The acoustic behaviour of resident bottlenose dolphins in Fiordland, New Zealand." University of Otago. Department of Marine Science, 2005. http://adt.otago.ac.nz./public/adt-NZDU20060728.140213.
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The bottlenose dolphin Tursiops truncatus is an extremely well-studied species. We have an extensive knowledge of certain aspects of their vocal behaviour, particularly from captive contexts. Bottlenose dolphins produce a rich tapestry of vocalisations, however, which have historically received minimal attention. Resident groups of bottlenose dolphins frequent the waterways of Fiordland in southwest New Zealand. These deep, sheltered fiords are ideally suited for acoustic studies.
This thesis presents the first detailed study of bottlenose dolphin acoustics in New Zealand. Both narrowband and broadband systems were used to record the vocalisations of two resident groups. Effort was distributed evenly over three years for both Doubtful Sound and Milford Sound. From 875 recordings, I proposed a repertoire of 15 discrete calls. These categories were subsequently compared using parameters measured from almost 2000 individual vocalisations. Various multivariate techniques revealed some redundancy in the proposed repertoire, and it was subsequently reduced to 12 calls.
The 12 call repertoire was compared between the potentially interbreeding populations of Doubtful Sound and Milford Sound. Fiord-specificity was revealed for many of the calls, particularly the sequenced calls and whistles. These differences suggest bottlenose dolphins use dialects, in keeping with studies of killer whales and sperm whales. As Fiordland dolphins are out of sight for 90% of the time, acoustic techniques allow inference in to subsurface behaviour. I investigated sequential relationships among sounds and between sounds and behaviours. Many calls were strongly implicated in social interactions. The vocalisations ratchet, orca and the sequenced calls were associated with periods of conflict. A number of the click-based calls were linked to diving and presumed foraging events.
Inference on the functional significance of sounds allowed an interpretation of habitat use. This appears to be the first study relating the entire vocal repertoire of a cetacean population to a complete home range. Areas important for socialising, foraging and resting are proposed. Local management decisions may be well served by this information. This study uses benign techniques to build on previous research in Fiordland, and adds a new dimension to the study of these populations.
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com, hugh finn@bigpond, and Hugh Colin Finn. "Conservation Biology of Bottlenose Dolphins(Tursiops Sp.) in Perth Metropolitan Waters." Murdoch University, 2005. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20051103.135358.
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This thesis examines two potential conservation problems for a residential sub-population of ~75 bottlenose dolphins (Tursiops sp.) in Cockburn Sound, a small embayment within the southern metropolitan waters of Perth, Western Australia: (1) human-induced habitat change and (2) illegal feeding (i.e. unregulated provisioning) of dolphins. The work is important because Cockburn Sound is the most intensively utilised marine environment in Western Australia and industrial, commercial, and recreational uses of the area will intensify in coming decades. These considerations, coupled with the demographic and ecological vulnerability of residential
populations of small cetaceans, suggested a risk of population decline without a more informed scientific basis for management. This study (2000 2003) complemented an earlier study of the Cockburn Sound dolphins (1993 1997) to provide a decade-long longitudinal study of the population. The original contributions of this study relate to: (a) the foraging ecology of dolphins;(b) the effects and mechanisms of human-dolphin interaction, particularly interactions based on unregulated provisioning; and (c) an integration of previous research and other information.
Studies of the foraging ecology of dolphins within Cockburn Sound were undertaken between 2000-2 to determine the areas used by dolphins and their feeding behaviours so that the implications of human-induced habitat change could be assessed. These studies used belt transect
sampling and event-specific sampling of foraging aggregations of dolphins to quantify the foraging habitat use of dolphins within the Sound and to characterise spatial and temporal patterns in aggregations of foraging dolphins. The results showed that the density of foraging
dolphins varied significantly across habitats and that foraging aggregations consistently occur in an area known as the Kwinana Shelf during the austral autumn-spring period. The studies also suggested that the foraging ecology of dolphins in Cockburn Sound reflects the consistent utilisation of both: (a) low-density prey species (i.e. individual or weakly-schooling prey) and (b)
high-density prey species (i.e. schooling species such as forage fish). These findings indicate that
ecosystem-based conservations of the population should consider the conservation requirements of dolphin prey species and the ecological integrity of key foraging habitats like the Kwinana Shelf.
Human-dolphin interactions based on the illegal feeding of dolphins in Cockburn Sound escalated between 1993 and 2003. By 2003, a total of 14 individuals exhibited behaviours indicative of conditioning to human interaction by food reinforcement, including some individuals that
engaged in provisioning interactions on a chronic (i.e. long-term) basis. Observations of the effects of unregulated provisioning indicated that: (a) provisioned dolphins sustained increased higher rates of human-induced injury than non-provisioned dolphins and (b) provisioning was associated with substantial and enduring behavioural changes including changes in ranging and association patterns. Other observations of human-induced injury in Cockburn Sound included seven instances of calf entanglement. These findings indicate that the effects of illegal feeding and other forms of direct human-dolphin interaction (e.g. entanglement) could achieve biological
significance for the population.
The possible contribution of (a) human influences, (b) social learning, and (c) behavioural
propensities (e.g. age and sex) on the acquisition of an attraction response to human provisioning was examined through logistic regression analysis using age, sex, use of high-boat density areas, and the number of close associates that were previously provisioned as predictor variables and the acquisition of an attraction response as the dependent variable. This analysis was supplemented
by behavioural observations of interactions between provisioned and naïve individuals during provisioning interactions. The results supported three findings: (1) a relatively high level of exposure to human provisioners was a significant predictor for the acquisition of an attraction response by dolphins; (2) social learning contributed to the acquisition of an attraction response in
those individuals that more frequently utilised high-boat density areas; and (3) the potential contribution of behavioural propensities relating to age and sex was uncertain. These conclusions suggest that the acquisition of an attraction response to human provisioning can best be
understood as the outcome of a complex of interacting factors.
The findings also indicate: (a) the management value of individual-specific and longitudinal data for the management of harmful human-wildlife interactions and (b) the potential for social learning to contribute to the development and persistence of these interactions.
The findings of this study indicate that population decline in Cockburn Sound could be induced by: (1) a reduction in the Sounds environmental carrying capacity or (2) mortality, injury, and behavioural changes resulting from interactions with humans. The potential for such a decline and evidence demonstrating the harmful effects of human activities on dolphins supports the
application of preventative approach to the management of illegal feeding and entanglement and a precautionary approach to environmental impact assessments of proposed developments. Mitigation of direct human-dolphins like illegal feeding requires an enforcement and education program to encourage more responsible human attitudes towards interactions with dolphins.
Research on the ecology and composition of finfish assemblages and the trophic structure of the Kwinana shelf would assist efforts to mitigate the impact of human-induced habitat change.
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Grave, Sofia Alexandra dos Reis. "Mapping bottlenose dolphin (Tursiopstruncatus) behaviour in the Southern coast of Portugal." Master's thesis, Universidade de Évora, 2022. http://hdl.handle.net/10174/31349.
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Mapeamento do comportamento do golfinho roaz (Tursiops truncatus) na Costa Sul de Portugal
RESUMO: O presente estudo visa mapear o comportamento do golfinho roaz na costa Sul de Portugal, descrevendo pela primeira vez tais comportamentos com uma componente geográfica. Este estudo baseia-se na análise de dados cedidos pela Associação para a Investigação do Meio Marinho (AIMM), recolhidos entre 2010 e 2020. Os resultados indicam que o golfinho roaz apresenta uma ampla ocorrência costeira ao longo da costa Algarvia. Foram encontradas diferenças significativas no tamanho do grupo entre as estações do ano, possivelmente, devido a fatores ecológicos da espécie. O comportamento de viajar foi o mais observado. As crias foram observadas, especialmente, no outono e verão, e estiveram presentes grupos que apresentaram todos os tipos de comportamentos. Foi também analisada a presença de barcos de dolphin-watching na proximidade dos golfinhos. Este estudo alarga o conhecimento acerca da ocorrência do golfinho roaz em Portugal, contribuindo também para a sua conservação; Abstract:
The aim of this study is to map the behaviour of bottlenose dolphin in the southern coast of Portugal, describing for the first time their behaviours with a geographical component. The data analysed was provided by Association for the Research of the Marine Environment (AIMM), collected between 2010 and 2020 along the south coast of Portugal. Bottlenose dolphin showed a wide coastal occurrence along the coast of the Algarve. Differences were found in group size between seasons possibly due to ecological factors of this species. Travelling was the most observed behaviour. Calves were sighted specially in the autumn and summer, and were present in groups which display each of the behavioural activities recorded. The presence of dolphin-watching boats in the vicinity of dolphin sightings was also analysed. This study improves the knowledge about the occurrence of the species in Portugal, contributing to their conservation.
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Silva, Monica Almeida. "Population biology of bottlenose dolphins in the Azores archipelago." Thesis, University of St Andrews, 2007. http://hdl.handle.net/10023/215.
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The ranging behaviour, habitat preferences, genetic structure, and demographic parameters of bottlenose dolphins living in the Azores were studied using data collected from 1999 to 2004. Only 44 dolphins out of 966 identified were frequently sighted within and between years and showed strong site fidelity. The remaining individuals were either temporary migrants from within or outside the archipelago, or transients. Estimates of home range size were three times larger than previously reported for this species, possibly as a result of the lower availability of food resources. Mitochondrial DNA sequences showed very high gene and nucleotide diversity. There was no evidence of population structuring within the Azores. The Azorean population was not differentiated from the pelagic population of the Northwest Atlantic, suggesting the "unproductive" waters of the Atlantic do not constitute a barrier to dispersal. Population size, survival and temporary emigration rates were estimated using open-population models and Pollock's robust design. A few hundreds of dolphins occur in the area on a given year, though the majority should use it temporarily, as suggested by the high emigration rates. Bottlenose dolphins preferentially used shallow areas with high bottom relief. Temporal and spatial persistence of dolphin-habitat associations documented in this study further supports the idea of a close relationship between certain bathymetric features and important hydrographic processes and suggests the occurrence of prey aggregations over these areas may be, to some extent, predictable. Several results of this study suggest there are no reasons for concern about the status of this population. Yet, the resident group may be negatively affected by increasing pressure from the whale watching activity. Although the proposed Marine Park constitutes important habitat for resident dolphins, at present, the area is clearly insufficient to satisfy their spatial requirements and its conservation value may be limited.
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Cowan, Rebecca Beth. "Short term memory for behavior in the Bottlenose Dolphin (Turisops truncates)." Thesis, University of Hawaii at Manoa, 2003. http://hdl.handle.net/10125/7097.
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We tested an adult female bottlenose dolphin's ability to repeat self-performed behaviors after a delay interval. Her memory fidelity was tested using four sets of increasingly long delay intervals. Repeat performance decreased as length of delay increased. However, the dolphin's repeat performance was significantly greater than would be expected by chance at all delay intervals tested (up to 120 seconds). Another study tested the dolphin's ability to transfer her delayed repeat ability to five behaviors not previously tested after incrementally increasing delay intervals. The dolphin was able to repeat three behaviors without error. A post-test analysis characterized the dolphin's posture and any behaviors occurring during delay intervals, in an attempt to identify memory strategies utilized by the dolphin. A final experiment introduced a distracter task, paddle pressing, during the delay interval, to study interference effects. Paddle pressing disrupted the dolphin's memory, but not so much that she remembered nothingvii, 80 leaves
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Holobinko, Anastasia. "Conflict and reconciliation behavior trends of the bottlenose dolphin (Tursiops truncatus) /." Available to subscribers only, 2006. http://proquest.umi.com/pqdweb?did=1203561731&sid=18&Fmt=2&clientId=1509&RQT=309&VName=PQD.
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Karle, Kristin A. "Structure and Function of Male Bottlenose Dolphin Alliances in Northeast Florida." UNF Digital Commons, 2016. http://digitalcommons.unf.edu/etd/640.
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Bottlenose dolphins exhibit fission-fusion social systems in which group size and composition change fluidly throughout the day. Societies are typically sexually segregated, and the quality and patterning of individual relationships in this social species shape the social structure of a population. Female dolphins usually have a large network of associates with whom they form recurring moderate bonds, while male associations are highly variable due to their mating strategies. Males employ one of two strategies; males may be solitary, and encounter and herd females individually, while others may form strong bonds with one to two other males and cooperatively herd individual females in the shape of a first-order alliance. Second-order alliances are more uncommon and have only been observed in Shark Bay, Australia, and more recently within the St. Johns River (SJR), Jacksonville, Florida. Given the inter-population variation in male mating strategies, greater documentation of social structure in neighboring populations along the Atlantic coast is needed. Therefore, chapter one documents the social structure of the Indian River Lagoon (IRL) estuarine system where dolphins have experienced recurrent cetacean morbillivirus (CeMV) epizootics. Although environmental disturbances can affect both social and mating systems, IRL dolphin sociality does not seem to be affected by the 2008 CeMV mass mortality event. Additionally, males only form first-order alliances within this population. Because multi-level alliances are unique to the SJR in this region, chapter two analyzes the stability and function of SJR alliances. Both first- and second-order alliances exhibited variation in stability, while alliance association appears dependent on female presence. Thus, SJR alliances likely function within a reproductive context. Together, this work provides insight into the social and mating systems of bottlenose dolphins, as well as the function of multi-level alliances at a relatively new study site.
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Cheney, Barbara Jean. "Temporal variation in the demographics and dynamics of a bottlenose dolphin population." Thesis, University of Aberdeen, 2017. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=236113.
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Long-term individual-based studies can be central to collecting data on aspects of individual and population biology and ecology. Photo-identification often underpins longterm individual based studies, particularly for cetaceans. Bottlenose dolphins (Tursiops truncatus) are long-lived with low reproductive rates and complex social structures, while showing plasticity in their behaviour, biology and ecology. As such long-term individual based studies are key to investigating the complexities of their population dynamics. My aim for this thesis was to synthesise over two decades of photo-identification data with the intention of exploring the value and contribution of a long-term individual based photo-identification study and answer key questions about the ecology and biology of bottlenose dolphins in Scottish waters. This thesis provides the first data on distribution and status of bottlenose dolphins around Scotland. Results highlighted the smaller population on the west coast split into two discrete communities with different ranging patterns and provided the first evidence that the highly mobile east coast population may be increasing. For the east coast of Scotland bottlenose dolphin population, laser photogrammetry identified morphological differences (larger size, no sexual dimorphism, no sex differences in growth) and highlighted fitness consequences to variation in early calf growth (calves that died over their first winter were significantly shorter). This thesis also identified differences in social structure over two decades at the two extremes of the population's range, potentially caused by or a consequence of, range expansion. Finally, this study provided empirical evidence of increasing trends in population abundance, reproductive rate and calf survival. This is a rare example of empirical evidence of a positive trend in demographic parameters of a cetacean population using a marine protected area. This work highlights the need for long-term individual based data to detect biologically meaningful change and suggests this small bottlenose dolphin population is a conservation success story.
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Estes, Melissa Kay. "A phylokaryotypic evaluation of the genus Tursiops (family Delphinidae)." PDXScholar, 1985. https://pdxscholar.library.pdx.edu/open_access_etds/3440.
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In an attempt to correlate genetic data with possible species delineation, this study investigates the presence of chromosomal variants between the North Atlantic bottle nose dolphin, Tursiops truncatus, and the North Pacific bottle nose dolphin, T. gilli. Blood samples were obtained from oceanaria in the United States. Location of capture was correlated with karyotype to compare chromosome morphology with geographic range.
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Heithaus, Michael R. "Habitat use decisions by bottlenose dolphins (Tursiops aduncus) and tiger sharks (Galeocerdo cuvier) in a subtropical seagrass ecosystem." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ61648.pdf.
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Parsons, Kim Michelle. "The use of molecular and observational data to infer the structuring of bottlenose dolphin populations." Thesis, University of Aberdeen, 2002. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=217232.
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Knowledge of the structuring of natural populations is important for understanding both evolutionary processes and population ecology, and for supporting management decisions. Conventional methods of direct observation often suffer from a lack of resolution, particularly when studying mobile animals in a marine environment. In this study, I combined direct observation with indirect molecular genetic approaches to infer the social and population structure of coastal (inshore) bottlenose dolphins, Tursiops truncatus. Genetic diversity and structure of bottlenose dolphins around the UK and Ireland was examined using tissue samples from stranded dolphins and incidental fisheries by-catch. Mitochondrial DNA (mtDNA) sequence data indicated significant subdivision among four main sample regions (NE Scotland, Wales, NW Scotland and Ireland). Genetic divergence between NE and NW Scotland populations, and low genetic diversity within the NE Scotland population, provide further support for the precautionary approach currently applied to the management of this population. Inference from both mtDNA and nuclear microsatellite genetic markers, and direct observational data were used to examine the social and population structure of bottlenose dolphins in the NE Bahamas. Novel strategies for collecting genetic samples (remote biopsy and faecal sampling) from free-ranging dolphins were developed and validated, enabling an individual-based analysis of population subdivision. Patterns of individual associations in two contrasting habitats indicated that environmental pressures affect dolphin grouping patterns; with a genetic basis for social affiliations occurring only where predation pressures are low. Nonetheless, a particularly notable feature of the social structure in both habitats was the persistence of stable alliances among maternally related males. At the population level, the significant degree of genetic structuring revealed among three sampled regions on Little Bahama Bank, supported the high degree of site fidelity suggested by individual-based photo-identification data. Contrary to the patterns of male dispersal and female philopatry common among both mammals and bottlenose dolphins, sex-specific patterns of genetic differentiation inferred from both mtDNA and microsatellite markers were indicative of female-mediated gene flow. This study provides novel insight into the factors governing the patterns of structuring within populations of highly mobile small cetaceans, and demonstrates the value of integrating both direct (field-based) and indirect (molecular genetic) data in the study of free-ranging animals.
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Lewis, Jennifer S. "Investigation of Group Leadership in a Fission-Fusion Species, the Bottlenose Dolphin." FIU Digital Commons, 2010. http://digitalcommons.fiu.edu/etd/254.
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Consistent leadership of group travel by specific individuals has been documented in many animals. Most species exhibiting this type of leadership have relatively stable group membership. Animals using fission-fusion grouping are not expected to use specific leaders because associations would not be frequent. Certain conditions, however, may allow this type of control over group travel to occur. First, a population would need to be small enough to allow regular associations between individuals. Second, leadership may be useful if the environment where the population in question lives is complex and requires learning to access the resources efficiently. To determine whether fission-fusion species existing under these conditions utilize specific individual leadership, I examined a small residential population of bottlenose dolphins (Tursiops truncatus) in the Lower Florida Keys (LFK) where the benthic habitat is highly complex. My goals were to 1) determine whether specific individuals in this population led group travel more often than expected; 2) determine whether certain factors predicted which animals would lead most often and 3) investigate the benefits of leading to leaders and to followers in a fission-fusion society. Multiple types of data were collected to answer questions posed including dolphin behavior (for leadership analyses), fish sampling (to examine dolphin habitat use under leadership), and dolphin biopsy sampling (for genetic analyses). Results of analyses provided strong evidence for consistent leadership in this population. Leaders were female, most were mothers and on average they had larger measures of centrality within the LFK population. Leaders benefited by leading individuals who were more closely related than expected. Followers benefited from efficient access to profitable habitat. Results build on previous leadership research by expanding our knowledge about the type of species in which specific individuals lead and predictors for what types of individuals may lead. Additionally, results provide the first detailed information about benefits group members obtain by both leading and following.
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Quintana-Rizzo, Ester. "Group fission-fusion dynamics and communication in the bottlenose dolphin (Tursiops truncatus)." [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001841.
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Thomas, Rebecca Elizabeth. "Relating behavioral context to acoustic parameters of bottlenose dolphin (Tursiops truncatus) vocalizations." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/29049.
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Thesis (Ph. D.)--Joint Program in Oceanography (Massachusetts Institute of Technology, Dept. of Biology, and the Woods Hole Oceanographic Institution), 2001.Includes bibliographical references.
This thesis presents methods to analyze the function of vocalizations of the bottlenose dolphin, Tursiops truncatus. The thesis uses the social interaction as the basic unit of analysis, and maintains a deliberate focus on quantitative and replicable analyses throughout. A method for determining identity of the vocalizing animal in a lagoon was developed. This method combined passive acoustic localization with video sampling to determine which animal vocalized. It fills an urgent need for unbiased identification of vocalizations of undisturbed dolphins where details of social interactions can be followed without affecting the behavior of the subjects. This method was implemented in a captive lagoon with 6 dolphins: two adult females, their two male calves, and a juvenile male and a juvenile female. This thesis also reviews the current state of analysis of the bottlenose dolphin acoustic repertoire, highlighting the need for a detailed, quantitative, and consistent study of the entire vocal repertoire. It does not attempt to do a comprehensive repertoire study, but uses several new quantitative methods to parameterize vocalizations and relate these to behavior from dolphins. Vocalizations within the lagoon tended to occur around the time of onset of behaviors produced by the focal dolphin. A comparison of vocalizations during affiliative and agonistic interactions revealed that the association of group vocalizations with the behavior of a focal animal was related to agonistic but not affiliative interactions.
Using the localization/video method, vocalizations in a time window around submissive behaviors were localized and classified as having come from either dolphins engaged in the interaction or dolphins not engaged in the interaction. Vocalizations were emitted by interactants more often than expected, and by non-interactants less often than expected. Use of different vocalization types was found to vary depending on the context of the agonistic interaction. In addition, the sequence of vocalizations with respect to behaviors within the interaction mattered, with more vocalizations occurring after than before submissive behaviors. These results demonstrated that group-based analyses of vocalizations are insufficient and one must use techniques designed to focus on the level of the interaction in order to study communication and social behavior in dolphins.
by Rebecca Elizabeth Thomas.
Ph.D.
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Currey, Rohan J. C., and n/a. "Conservation biology of bottlenose dolphins in Fiordland, New Zealand." University of Otago. Department of Marine Science, 2009. http://adt.otago.ac.nz./public/adt-NZDU20090730.141243.
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The bottlenose dolphins of Fiordland, New Zealand, live at the southern limit of the species' worldwide range. They are exposed to impacts from tourism and habitat modification, particularly in Doubtful Sound, and their conservation requirements are presently unclear. Dolphin abundance was estimated in Doubtful Sound using photo-identification census and capture-recapture techniques (56 individuals; 95% CI: 55-57), detecting a decline of 34-39% over 12 years among adults and sub-adults (>3 years old). The cause of this decline was investigated via demographic modelling in Doubtful Sound and a comparative assessment of population status in Dusky Sound.
Capture-recapture modelling of photo-identification data compiled since 1990 yielded a constant adult survival rate marginally lower than prior estimates for wild bottlenose dolphins ([phi]a(1990-2008) = 0.9374; 95% CI: 0.9170-0.9530). Survival of calves (<1 year old) declined to an unsustainable level that is thought to be the lowest recorded for wild bottlenose dolphins ([phi]c(2002-2008) = 0.3750; 95% CI: 0.2080-0.5782) coincident with the opening of a second tailrace tunnel for a hydroelectric power station. Reverse-time capture-recapture modelling detected declines in recruitment (f(1994-2008) = 0.0249; 95% CI: 0.0174-0.0324) and population growth ([lambda](1994-2008) = 0.9650; 95% CI: 0.9554-0.9746) over time consistent with the decline in calf survival (<1 year old) and a separate reduction in juvenile survival (1 to 3 years old) reflecting cumulative impacts.
Dolphin abundance was estimated in Dusky Sound using photo-identification census and capture-recapture techniques (102 individuals, 95% CI: 100-104) providing no evidence of interchange with Doubtful Sound. A comparative assessment of health status between Doubtful and Dusky Sounds revealed skin lesioning was more severe in Doubtful Sound, particularly among females, and newborn calves appeared to be smaller and were born over a shorter period: factors that may contribute to the low levels of calf survival in Doubtful Sound. The Fiordland bottlenose dolphins were assessed under IUCN Red List regional criteria. The small size of the population (205 individuals, 95% CI: 192-219) combined with the projected rate of decline in stochastic matrix models (average decline 31.4% over one generation) resulted in a recommended classification of Critically Endangered.
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Stuby, Richard George Jr. "A stochastic measure of similarity between dolphin signature whistles." Thesis, Virginia Tech, 1993. http://hdl.handle.net/10919/31408.
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Bottlenose dolprlin (Tursiops trunratus) whistles are currently studied by subjective visual comparison of whistle spectrograms. This thesis describes the novel use of stochastic modeling to automate the comparison of dolphin whistles and to yield an objective, quantitative measure of whistle similarity. The relationship of bottlenose dolphin whistle production to a model of human speech production is discussed, providing a basis for the use of human speech recognition techniques for creating whistle models.
Discrete hidden Markov models based on vector quantization of linear prediction coefficients are used to create whistle models based on statistical information derived from a sample set of dolphin whistles. Whistle model comparison results are presented indicating that evaluation of bottlenose dolphin whistles via hidden Markov modeling provides an objective measure of similarity between whistles. The results also demonstrate that hidden Markov models provide robustness against the effects of temporal and frequency variance in the comparison of whistles. The extensibility of stochastic modeling techniques to other animal vocalizations is discussed and possibilities for further work in areas such as the determination of possible structural components, similar to phonemes in human speech, is provided.Master of Science
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Kaiser, Sabina Marie Luise. "Feeding ecology and dietary patterns of the Indo-Pacific bottlenose dolphin (Tursiops Aduncus) off KwaZulu-Natal, South Africa." Thesis, Nelson Mandela Metropolitan University, 2012. http://hdl.handle.net/10948/d1011509.
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The Indo-Pacific bottlenose dolphin (Tursiops aduncus) is a common top predator along the KwaZulu-Natal coast. There have been several dietary studies done on this species, most of which have classed this predator as an opportunistic feeder preying on the most abundant prey species in that area. In KwaZulu-Natal (KZN) a dietary study was carried out in 1990, but there have been no followup studies to examine potential changes in diet. A number of bottlenose dolphins get entangled in the shark-nets set off the KZN coast each year. These dolphins provide a valuable source of information about different aspects of the ecology of this population. The aim of this study was to examine the diet of bottlenose dolphins off the KwaZulu-Natal coast with particular emphasis on temporal change in diet composition. The contents of 102 stomachs of bottlenose dolphins (58 females, 44 males) accidentally caught in the shark nets between 1985 and 2010 were analysed, and compared to historical data from dolphins caught between 1975 and 1986. A total of 94 different prey species from 37 families (32 fish families, five cephalopod families) were identified in the stomach contents. Teleosts made up the most important prey group in numbers and weight constituting 84 percent and 67 percent, respectively, while cephalopods made up 15 percent of the number and 30 percent of the weight of the prey items. Multi Dimensional Scaling (MDS) indicated that there is no resource partitioning between males and females, but significant partitioning between juveniles and adults. Six prey species contributed more than 60 percent of the weight of all prey species in the diet. These species are the most important according to their calculated index of relative importance score and are, in order of importance: Sepia sp. (cuttlefish)., Pomadasys olivaceus (piggy), Trachurus delagoa (maasbanker), Scomber japonicus (mackeral), Loligo sp. (squid). and Pagellus bellottii natalensis (pandora or red tjor-tjor). When compared to historic data, no changes in the main prey species has occurred, but the piggy has decreased in importance (1976-1986 percent IRI=45; 2000-2010 percent IRI=22), while the maasbanker has increased (1975-1986, percent RI=4; 2000-2010 percent RI=20). Stable carbon and nitrogen isotope analysis performed on tissue from the teeth of T. aduncus caught in the shark nets between 1970 and 2010 showed that there has been no significant shift in trophic level (δ15N) or in primary prey source (δ13C) over this time. The isotopic signatures of different tissues from an individual were used to create a base line and describe the differences in tissue signatures. Blubber was found to be significantly different from skin and muscle, which were found to be isotopically similar. Skin from remote biopsies can therefore probably be used in place of muscle for isotopic studies of bottlenose dolphins, while caution should be taken when using blubber. Given that T. aduncus is still listed as “data deficient” by the International Union for the Conservation of Nature (IUCN), and the potential for climate change and expanding fisheries to alter the distribution and abundance of their prey species, long term dietary studies such as this are important in order for their effective conservation and management.
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Dible, S. A. "Sonar properties of the lower jaw of the Atlantic bottlenose dolphin (Tursiops truncatus)." Thesis, Loughborough University, 2008. https://dspace.lboro.ac.uk/2134/12929.
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The primary function of this research project has been to investigate the physical properties of the lower jaw of the Atlantic Bottlenose Dolphin (Tursiops truneatus). This has been achieved through numerical modelling techniques, established physical measurements and modem Laser Doppler Velocity Measurements. During the course of this work some interesting characteristics of the dolphin jaw structure have been discovered. Sound speeds and attenuation levels of the jawbone have been determined and the implications assessed. The geometric array formed by the dolphin teeth of the lower jaw can be used to form an end-fire array which produces a beam pattern similar to those of the dolphin. The geometric array has also been analysed for its passive acoustical properties, in particular its ability to form acoustic stop bands within the audible range of the dolphin. The results of this research show that the directivity of the dolphin can be reproduced using the morphological features of the lower jaw.
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Nowacek, Douglas Paul. "Sound use, sequential behavior and ecology of foraging bottlenose dolphins, Tursiops truncatus." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/85611.
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Thesis (Ph. D.)--Joint Program in Biological Oceanography (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), 1999.Includes bibliographical references.
Odontocetes are assumed to use echolocation for navigation and foraging, but neither of these uses of biosonar has been conclusively demonstrated in free-ranging animals. Many bats are known to use echolocation throughout foraging sequences, changing the structure and timing of clicks as they progress towards prey capture. For odontocetes, however, we do not know enough about their foraging behavior to describe such sequences. To conduct detailed behavioral observations of any subject animal, the observer must be able to maintain continuous visual contact with the subject for a period commensurate with the duration of the behavior(s) of interest. Behavioral studies of cetaceans, which spend approximately 95% of their time below the water's surface, have been limited to sampling surface behavior except in special circumstances, e.g. clear-water environments, or with the use of technological tools. I addressed this limitation through development of an observation platform consisting of a remote controlled video camera suspended from a tethered airship with boat-based monitoring, adjustment, and recording of video. The system was used successfully to conduct continuous behavioral observations of bottlenose dolphins in the Sarasota Bay, FL area. This system allowed me to describe previously unreported foraging behaviors and elucidate functions for behaviors already defined but poorly understood. Dolphin foraging was modeled as a stage-structured sequence of behaviors, with the goal-directed feeding event occurring at the end of a series of search, encounter, and pursuit behaviors. The behaviors preceding a feeding event do not occur in a deterministic sequence, but are adaptive and plastic. A single-step transition analysis beginning with prey capture and receding in time has identified significant links between observed behaviors and demonstrated the stage-structured nature of dolphin foraging. Factors affecting the occurrence of specific behaviors and behavioral transitions include mesoscale habitat variation and individual preferences. The role of sound in foraging, especially echolocation, is less well understood than the behavioral component. Recent studies have explored the use of echolocation in captive odontocete foraging and presumed feeding in wild animals, but simultaneous, detailed behavioral and acoustic observations have eluded researchers. The current study used two methods to obtain acoustic data. The overhead video system includes two towed hydrophones used to record 'ambient' sounds of dolphin foraging. The recordings are of the 'ambient' sounds because the source of the sounds, i.e. animal, could not be localized. Many focal follows, however, were conducted with single animals, and from these records the timing of echolocation and other sounds relative to the foraging sequence could be examined. The 'ambient' recordings revealed that single animals are much more vocal than animals in groups, both overall and during foraging. When not foraging, single animals vocalized at a rate similar to the per animal rate in groups of>=2 animals. For single foraging animals, the use of different sound types varies significantly by the habitat in which the animal is foraging. These patterns of use coupled with the characteristics of the different sound types suggest specific functions for each. The presence of multiple animals in a foraging group apparently reduces the need to vocalize, and potential reasons for this pattern are discussed. In addition, the increased vocal activity of single foraging animals lends support to specific hypotheses of sound use in bottlenose dolphins and odontocetes in general. The second acoustic data collection method records sounds known to be from a specific animal. An acoustic recording tag was developed that records all sounds produced by an animal including every echolocation click. The tag also includes an acoustic sampling interval controller and a sensor suite that measures pitch, roll, heading, and surfacing events. While no foraging events occurred while an animal was wearing an acoustic data logger, the rates of echolocation and whistling during different activities, e.g. traveling, were measured.
by Douglas Paul Nowacek.
Ph.D.
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Karczmarz, Veronika. "Evaluation of live fish as an echolocation enrichment for the bottlenose dolphin (Tursiops truncatus)." Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-131465.
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Bottlenose dolphins (Tursiops truncatus) kept in zoos and dolphinarias rarely get an outlet for their echolocation abilities as their pool environment is often quite barren. Not much research has been carried out on enrichments promoting echolocation for dolphins in human care. In the present study a setup with live fish was compared to a setup with air-filled floats (providing strong sonar targets, similar to the swim bladders of large fish) and a control setup. A PCL (porpoise click logger) was used to record the echolocation click trains produced by the dolphins and aimed at the three setups. Behavioural data was also collected from video footage. Both the PCL data and all the behavioural observations indicated that the fish setup was more interesting than the float and the control setup, for the dolphins to echolocate towards. However, there were some contradictions with some parameters, where the floats and control seemed to be more interesting. This was probably due to the location of the PCL hydrophone in relation to the floats and fish, and not because the dolphins had a real bigger interest in these setups. To increase the possibility for dolphins to perform more echolocation in human care and increase their welfare, live fish can be recommended as echolocation enrichment.
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Lemerande, Tobias J. "Transmitting beam patterns of the Atlantic bottlenose dolphin (Tursiops Trucatus) : investigations in the existence and use of high frequency componenets found in echolocation signals /." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02Jun%5FLemerande.pdf.
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Blomqvist, Christer. "Directional aggressive pulse sounds in the Bottlenose Dolphin (Tursiops Truncatus) : technical aspects and social implications /." Linköping : Univ, 2004. http://www.bibl.liu.se/liupubl/disp/disp2004/tek905s.pdf.
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Marques, Gonçalo Nogueira. "Clinical approach to respiratory mucormycosis in a bottlenose dolphin (Tursiops truncatus) calf under human care." Master's thesis, Universidade de Lisboa, Faculdade de Medicina Veterinária, 2019. http://hdl.handle.net/10400.5/19336.
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Dissertação de Mestrado Integrado em Medicina VeterináriaSeveral fungi are described to cause invasive infections in dolphins, the respiratory system being a common site of involvement. Mucormycosis is considered one of the most devastating fungal infections in dolphins, associated with an elevated mortality rate, where hyphae are capable of invading blood vessels, producing tissue infarction and necrosis. A one-year-old male bottlenose dolphin (Tursiops truncatus) calf presented with a history of recurrent episodes of leukocytosis and occasional respiratory signs. During a routine faecal examination, a myriad of hyphae were found. Fungal culture revealed a mucormycete isolation, the aetiologic agent of mucormycosis. Molecular studies allowed to identify Cunninghamella bertholletiae. Thoracic radiographs showed the presence of a bronchoalveolar pattern on both the right and left lung apexes. A bronchoscopy was performed, which revealed multiple whitish lesions, diffusely distributed on the tracheal and bronchial submucosa. The antifungal therapy prescribed was a combination of posaconazole and aerosolized liposomal amphotericin B. Adjunctive therapies included bromhexine, vitamin C, vitamin B complex, probiotics, silymarin, Imuno-2865™ and ozone therapy. Follow-ups were conducted with haematology and blood biochemistry, faecal and sputum culture and direct microscopy, and bronchoscopies. There was a good overall response to treatment and antifungal therapy was discontinued. However, the infection relapsed and posaconazole therapy was restarted. Serum concentrations of posaconazole were retrospectively evaluated and the set of results did not appear to show subtherapeutic concentrations as a plausible explanation for the relapse. Although complete clinical resolution was not obtained during the timeframe considered, this case corroborates the idea that medical management of mucormycosis is possible, especially with a prompt diagnosis and treatment as well as a tight follow-up protocol. As described in the literature, mucormycosis treatment may take several years and relapses are common.
RESUMO - Maneio médico de mucormicose respiratória numa cria de golfinho-roaz (Tursiops truncatus) em contexto zoológico - Várias espécies de fungos estão descritas como agentes etiológicos de infeções invasivas em golfinhos, sendo o sistema respiratório um dos locais comuns de infeção. A mucormicose é uma das infeções fúngicas invasivas com efeitos mais devastadores, associada a uma elevada taxa de mortalidade em cetáceos. Nesta dissertação é apresentado um caso clínico referente a uma cria de golfinho-roaz (Tursiops truncatus) com um ano de idade, com uma história clínica que incluía episódios recorrentes de leucocitose e ocasionais sinais clínicos de etiologia respiratória. Como parte do programa de medicina preventiva instituído, uma análise microscópica de fezes permitiu a visualização de estruturas fúngicas. A cultura fúngica permitiu o isolamento de um mucormicete, o agente etiológico da mucormicose, e através de PCR e sequenciação foi possível identificar Cunninghamella bertholletiae. Estudos imagiológicos demonstraram a presença de um ligeiro padrão broncoalveolar nos ápices pulmonares e o exame endoscópico permitiu visualizar múltiplas lesões esbranquiçadas, difusamente distribuídas pelas mucosas traqueal e brônquica. O tratamento antifúngico consistiu na administração de comprimidos gastrorresistentes de posaconazol e nebulizações com anfotericina B lipossómica. Tratamentos adjuvantes incluíram bromexina, silimarina, suplementação vitamínica, probióticos, Imuno-2865TM e ozonoterapia. O acompanhamento do caso foi feito com base em dados hematológicos e bioquímicos, análises microscópicas/cultura de fezes e exsudado respiratório e broncoscopias. O tratamento com posaconazol foi descontinuado após 95 dias de terapia, tendo em conta os resultados constantemente negativos na cultura e observação microscópica de amostras fecais e exsudado respiratório. No entanto, verificou-se a recidiva da infeção e o tratamento antifúngico foi recomeçado. As concentrações séricas do fármaco ao longo do caso clínico foram retrospetivamente analisadas e esta monitorização permitiu descartar a hipótese de não terem sido atingidas concentrações séricas terapêuticas como causa da recidiva da infeção. Apesar de não ter existido uma completa resolução clínica no período considerado, este caso corrobora o facto do maneio médico da mucormicose em cetáceos ser possível, através de um diagnóstico e tratamento precoces, além de um plano apertado de seguimento clínico. Como descrito na bibliografia, o tratamento da mucormicose pode demorar vários anos e recidivas são comuns.
N/A
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Gaspar, Raquel. "Status of the resident bottlenose dolphin population in the Sado estuary : past, present and future." Thesis, University of St Andrews, 2003. http://hdl.handle.net/10023/10974.
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The main aim of this work was to determine the past, present and future conservation status of the bottlenose dolphin population inhabiting the Sado estuary region, Portugal, using a long term (photo ID) data set. Resident animals, identified from their strong resighting pattern, were confined to the estuary region. There is little evidence of social interchange with other coastal bottlenose dolphins and the role of emigration and immigration is unclear. This is a very small population. Numbers of animals have decreased in the past but now seem to be increasing. A mark-recapture analysis of individual capture histories showed that time changes in age-specific survival explained the observed changes in number of animals. Survival was lower, particularly in young animals, in earlier years which have resulted in a long period of lack of recruitment to adulthood. In the most recent years survival has increased, especially for calves in their second and third years. Fecundity has also been higher. Protected areas and proposed marine SACs reflect the importance of the Sado estuary region; this is also an area of intense anthropogenic activities that threaten the dolphin population. Population viability analysis was conducted using the software VORTEX incorporating estimates of past or current vital rates. The likely future of the resident population is for it to decline, especially during the next few decades. A viable population was only predicted if maximum values of vital rates were used or if regular immigration occurred. A number of proposals for management action are discussed. This work constitutes an example in conservation biology where life history parameters were estimated, and used to predict future viability and thus to indicate management actions that could increase the chance of saving a very small marine mammal population.
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Smith-Goodwin, Jacqueline Anne. "A molecular genetic assessment of the population structure and variation in two inshore dolphin genera on the east coast of South Africa." Thesis, Rhodes University, 1998. http://hdl.handle.net/10962/d1004067.
Full textAbstract:
Coastal dolphins on the South African east coast are threatened by degradation and loss of habitat as a result of increasing coastal development, industrial effluent and agricultural runoff. In addition, dolphins off the coast of KwaZulu-Natal have, for more than four decades, been heavily exploited through unchecked incidental capture in shark nets set at 45 beaches. In light of the high rate of mortality and apparent depletion of both species, the persistence of bottlenose (Tursiops truncatus) and humpback (Sousa chinensis) dolphins in that region has been questioned. Genetic variation in south east African dolphin populations was determined as a means of assessing the fitness of the populations and their resilience to demographic disturbances. Furthermore, in order to determine the effects of continued mortality on the KwaZulu-Natal subpopulations, it was necessary to determine whether they are open or closed to immigration from the adjacent East Cape region, which represents a relatively unstressed region, characterised by a lack of shark nets and less intensive coastal activities. Genetic variation and differentiation in the maternal genome was assessed by determining the sequence of the first 400 bases of the mtDNA control region in bottlenose and humpback dolphins from KwaZulu-Natal and the East Cape. Nuclear variation and differentiation was estimated at six microsatellite loci and compared with earlier estimates determined from allozyme electrophoresis. Random amplified polymorphic DNA (RAPD) was assessed as a means of identifying population subdivisions and diagnostic population markers. Both bottlenose and humpback dolphins on the South African east coast are characterised by low nuclear and organellar genetic variation, consistent with a possible genetic bottleneck, the inferred date of which coincides with the onset of the last glacial period. Genetic variation in South African bottlenose dolphins was lower than that reported elsewhere for the species, while an intraspecific comparison supported lower genetic variation in South African humpback dolphins than in humpback dolphins sampled off Hong Kong. An analysis of molecular variance (AMOVA), performed on mtDNA haplotype frequency data indicated, for both species, significant genetic subdivision, concordant with geographic location. The data suggested female bottlenose dolphins demonstrate regional philopatry, displaying limited movement between KwaZulu-Natal and the East Cape. Female humpback dolphins tend towards strict local philopatry, with significant maternal differentiation evident both within and between regional subdivisions. Differentiation in microsatellite allele frequencies was also demonstrated between KwaZulu-Natal and the East Cape for both species, suggesting that the movement of male bottlenose and humpback dolphins may also be restricted. Nonetheless, considerably higher nuclear gene flow estimates suggested that males of both species represent the principal vectors of gene dispersal. The implications of historically low genetic variability and population subdivision in South African dolphins are important in view of the current rate of mortality in KwaZulu-Natal. The persistence of coastal dolphin populations relies on their ability to recover following a bottleneck event. Continued removal of demographically important age-sex classes such as occurs in shark nets, may not only further reduce the genetic variation, but would ultimately deplete dolphin populations in KwaZulu-Natal beyond a sustainable number, resulting in eventual local extinction. The differentiation of the two regions implies that, in the event of local extinction occurring, dolphins, particularly females, from adjacent regions will not readily re-colonise the area. This would result in fragmentation of the south east African populations and ensure reproductive isolation from neighbouring populations on the east African coast.
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Moreno, Maria Paula Teixeira. "Environmental predictors of bottlenose dolphins distribution and core feeding densities in Galveston Bay, Texas." Texas A&M University, 2005. http://hdl.handle.net/1969.1/3803.
Full textAbstract:
Coastal dolphins are often exposed to habitat degradation and direct interactions with
humans. Major factors that influence dolphin distribution, critical for conservation
concerns, are still poorly understood even for the bottlenose dolphin, the best-studied
cetacean. To establish the environmental conditions that best predict occurrence of
bottlenose dolphins and high feeding densities in Galveston Bay, I conducted a total of
367 boat surveys in five locations of the estuary, totaling 3,814.77 km of search effort. I
counted groups of dolphins and measured surface water temperature, salinity, turbidity,
total number of boats, shrimp vessels, and number of seabirds. Using geospatial tools,
these data -- along with location, distance to the Gulf of Mexico and water depth -- were
analyzed on a 500- m resolution grid. Temporal factors at daily and seasonal scales were
also examined. Occurrence was modeled using a Generalized Additive Model and core
feeding densities (i.e., feeding densities above 2 SD of the mean) were modeled with a
Generalized Linear Model. A total of 1,802 dolphins in 262 groups were detected,
56.87% of which were feeding. I found that all factors except warm/cold seasons and
turbidity were useful to predict dolphin distribution, which was related non-linearly to
most predictors. Fewer variables were relevant in predicting core feeding densities.
These were, in decreasing order of relevance, distance to the Gulf of Mexico, surface
water temperature, depth, number of boats, and warm/cold seasons. Feeding was highly
clustered and the main core areas, less than approximately 3 km2 wide, were stable
across time of day and season. The majority of the occurrences (86.2%) and feeding
groups (94%) were situated in two bay locations - Galveston Ship Channel (GSC) and
Bolivar Roads (BRD) - that amounted to only one- fifth of the surveyed area. Compared
to conditions in GSC and BRD when no dolphins were sighted, feeding cores weredeeper and more seabirds were observed. This fine-scale study of bottlenose dolphin
distribution may contribute to a better understanding of habitat requirements for coastal
dolphins. It also may provide information needed to minimize potential negative impacts
to this population caused by human activities.