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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.
81

Synchrony in adult male Atlantic Spotted Dolphins (Stenella frontalis) during aggression

Unknown Date (has links)
Synchrony between Atlantic spotted dolphins (Stenella frontalis) is crucial for successfully fending off bottlenose dolphins (Tursiops truncatus) during interspecies aggression. The present study examined synchrony in adult Atlantic spotted dolphins during aggressive encounters with bottlenose dolphins. Across group size, aggressive behavioral events increased preceding synchrony, peaked during synchrony, and decreased dramatically after synchrony. Although smaller groups (< 10 dolphins) became synchronous more frequently than larger groups (> 10 dolphins), larger groups remained synchronous longer; however, smaller groups exhibited more frequent aggressive behavioral events during synchrony, suggesting that additional aggressive behaviors may be necessary to compensate for the small group size, whereas larger groups may be able to rely on synchrony alone. Disorganized squawk bouts synchronized as physical synchrony began, but only if coupled with escalating aggressive behaviors. The synchrony during aggressive episodes observed in adult Atlantic spotted dolphins can be used as a baseline to determine the process of the development of this critical skill in juveniles. / Includes bibliography. / Thesis (M.A.)--Florida Atlantic University, 2015 / FAU Electronic Theses and Dissertations Collection
82

Caracterização genética da região controladora do mtDNA e de loci de microssatélites das subpopulações de tursiops truncatus(cetacea, delphinidae) do complexo lagunar de Santo Antônio dos Anjos, Santa Catarina, e litoral norte do Rio Grande do Sul

Costa, Ana Paula Borges de Camargo 27 February 2013 (has links)
Submitted by William Justo Figueiro (williamjf) on 2015-06-15T23:23:28Z No. of bitstreams: 1 18.pdf: 1003465 bytes, checksum: 4ec0188cddd4cd7f3d6c8b0b4e08a5b0 (MD5) / Made available in DSpace on 2015-06-15T23:23:28Z (GMT). No. of bitstreams: 1 18.pdf: 1003465 bytes, checksum: 4ec0188cddd4cd7f3d6c8b0b4e08a5b0 (MD5) Previous issue date: 2013-02 / Nenhuma / Espécimes depositados em coleções científicas são uma importante fonte de DNA para identificações taxonômicas e estudos de genética de populações. Isso é especialmente verdadeiro para as espécies raras, as quais têm um grande valor científico em função do seu pequeno tamanho amostral em museus. Além disso, muitas vezes, o acesso às coleções para a realização de estudos moleculares sobre estes táxons só é possível através do uso de técnicas de extração de DNA não-invasivas. Um método alternativo que evita a destruição das amostras de museus e de extração eficiente é apresentado no presente trabalho para quatro exemplares de boto-da-tainha (Tursiops truncatus) coletados ao longo da costa de Santa Catarina, Brasil, entre os anos de 1985 e 2007. Com o auxílio de uma furadeira (modelo Bosch GSR 14,4-2) com brocas de cerca de 2 mm foram feitos pequenos furos em dentes de espécimes fisicamente adultos de Tursiops truncatus da coleção do Laboratório de Mamíferos Aquáticos da Universidade Federal de Santa Catarina (LAMAQ/UFSC). Foram retirados entre 100-150 mg de pó de dentina/cemento e desmineralizados por 7 dias à 55º C com 950 µl de EDTA (0,5 M; pH 8). Este material foi incubado à 55º C overnight para que as células sofressem digestão de proteínas e RNA pela ação de 300 µl de Tampão ATL, 20 µl de Proteinase K e 1 µl de RNAse. A etapa final foi concluída pelo kit de extração Qiagen DNA Investigator (QIAGEN®). A eficiência do DNA extraído foi testada através da amplificação de um fragmento de no mínimo 362 pares de base (pb) da região controladora do DNA mitocondrial em quatro espécimes de T. truncatus. Um total de dois haplótipos com 11 sítios polimórficos foram encontrados. O alto polimorfismo observado é uma possível decorrência da grande variabilidade genética do gênero Tursiops. Em casos onde existe a hipótese de subespécies baseada em caracteres morfológicos, a identificação molecular pode ajudar a atribuir os espécimes de museus a cada ecótipo, sendo de extrema importância o uso de métodos de extração eficientes e não-invasivos, como o demonstrado aqui, para a obtenção de resultados satisfatórios e preservação dos exemplares. / Museum specimens are an important source of DNA for taxonomic identifications and population genetics studies. This is especially true for rare species, which has great scientific value due to its small sample size in museums. Moreover, often, access to collections for performing molecular studies on these taxa is only possible through the use of nondestructive DNA extraction techniques. An alternative method, which avoids the destruction of museum samples and with an efficient DNA extraction is presented here for four bottlenose dolphins (Tursiops truncatus) specimens collected along the coast of Santa Catarina, Brazil, from 1985 to 2007. This is the first study in Brazil to amplify teeth DNA of T. truncatus for the mtDNA control region. Using a drill (Bosch GSR 14.4-2 model) with drill bits of about 2 mm, small holes were made in teeth of specimens of Tursiops truncatus physically adults deposited in the collection of the Laboratório de Mamíferos Aquáticos, Universidade Federal de Santa Catarina (LAMAQ/UFSC). Between 100-150 mg of powdered dentin/cementum were removed and demineralized for 7 days at 55° C with 950 µl of EDTA (0.5 M, pH 8). This material was incubated at 55° C overnight to the cells suffer digestion of proteins and RNA by the action of 300 µl of Buffer ATL, 20 µl Proteinase K and 1 µl of RNAse. The final step was completed by the extraction kit Qiagen DNA Investigator (QIAGEN®). The efficiency of the extracted DNA was tested by amplification of a fragment of at least 362 base pairs (bp) of the mitochondrial DNA control region in four specimens of T. truncatus. A total of two haplotypes were defined from 11 polymorphic sites. The high polymorphism detected is a possible consequence of the great genetic variability of the genus Tursiops. In cases where there is the subspecies hypothesis based on morphological data, molecular identification can help to assign these museum specimens to each ecotypes, being extremely important the use of efficient and nondestructive extraction methods, as showed here, to obtain satisfactory results and to conserve the specimens.
83

Biology, ecology and anthropogenic threats of Indo-Pacific bottlenose dolphins in east Africa

Amir, Omar A. January 2010 (has links)
This thesis examines the biology, ecology and anthropogenic threats of Indo-Pacific bottlenose dolphins (Tursiops aduncus) off Zanzibar, Tanzania, based on research conducted and samples collected between 2000 and 2008. Distribution and occurrence are described based on incidental catches (bycatch) in gillnet fisheries. Biology and ecology are examined by ageing and studying the reproductive biology and stomach contents of collected specimens. The composition of organohalogen compounds is determined in blubber samples, and assessment and mitigation of bycatch are conducted using observers onboard fishing vessels. Fisheries bycatch data showed that Indo-Pacific bottlenose dolphins occur year round in all areas around Zanzibar. Sexual maturity was attained between 7 and 8 years and body length 190-200 cm in females and at 16 years and body length 213 cm in males. The gestation period was estimated to be 12.3 months, with calving occurring throughout the year, peaking November-March and with an interval of 2.7 years. The estimated pregnancy rate was between 0.10 and 0.58 depending on methods used. Stomach contents revealed a relatively large number of prey species, but that only a few small- and medium-sized neritic fish and cephalopods contribute substantially to the diet. Estimates of total annual bycatch were &gt;9% which is not considered sustainable. An experiment showed that pingers can be a short term mitigation measure to reduce bycatch of dolphins in both drift- and bottom set gillnets. Methoxylated polybrominated diphenyl ethers (Meo-BDEs) were found at higher concentrations than anthropogenic organic pesticides (OCPs), with only traces of polychlorinated biphenyls (PCBs) detected. This study reveals the magnitude and apparent susceptibility of Indo-Pacific bottlenose dolphins off Zanzibar to anthropogenic threats, especially fisheries bycatch, and it is clear that immediate conservation and management measures are needed to reduce bycatch. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Submitted. Paper 4: Manuscript. Paper 5: Submitted.
84

Ocupa??o de ?rea e intera??es de golfinhos-rotadores (Stenella longirostris) com o turismo n?utico no Arquip?lago de Noronha/PE, Brasil

Tischer, Marina Consuli 29 March 2011 (has links)
Made available in DSpace on 2014-12-17T15:37:04Z (GMT). No. of bitstreams: 1 MarinaCT_DISSERT_pag1_ate_pag15.pdf: 10459545 bytes, checksum: bd3fb5e5db3d1c521824ec8eb3c3b82c (MD5) Previous issue date: 2011-03-29 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Several works characterize the presence of spinner dolphins at Fernando de Noronha Archipelago in the Dolphins Bay. Though, the dolphins abidance inside this cove has decreased and a new area has been occupied by the animals to achieve the same behaviors, that are resting, breeding and nursing. This area comprises the Inside Sea northeast border of Fernando s de Noronha Island, including the opposing Middle and Dog shore area, the San Antonio Bay and the Between Islands region. The aim was to characterize the dolphins occupation and describe their interactions with the tourism in this area. Data were collected in 2008 and 2009 through a fixed point observation. The study area was divided into seven sub-areas, recording: presence/absence of dolphins, days abidance endurance, abidance length in each area, estimated number of individuals, dolphins direction and speed of displacement, boats presence, interaction period, monitoring, boats attitude and velocity. The dolphins abidance time displayed the same pattern during both years of study, with the higher occupancy in the Between Islands region. Groups with farther than 200 individuals were more frequent both 2008 (46.2%) and 2009 (42.3%). Thus the displacement s slow speed as the preferred direction towards Rat Island also showed the same pattern in both years. The Between Islands region also presented the boats major abidance near the dolphins groups. Boats moved farther in slow speed (95%) than at high speed (5%). The legislation s compliance for the cetaceans protection occurred in 89.7% of 2.839 interactions between boats and spinners, in which this variable was recorded. Whenever boats moved at a slow speed during the meetings with spinner dolphins groups, animals also moved at a slow speed (n = 337), significantly more than the fast displacements (n = 128) ix or "porpoise" (n = 4) (X2 = 318.543, p = -0.001). When boats quickly passed by groups, a significant difference between the dolphins displacement speeds was observed (X2 = 18.264, p =- 0.001), however, the slow (47%) and fast (47% ) displacements frequency was equal, noted the difference with the porpoise displacements (6%), which had the lowest frequency. Data indicate the establishment of a new occupation pattern of the spinner dolphins at Fernando de Noronha, with the Between Islands area being of great importance to the dolphins habits and currently the main area of the boats meeting with the dolphins, showing the need of new conservation measures in this area / Diversos trabalhos caracterizam a presen?a de golfinhos-rotadores no Arquip?lago Fernando de Noronha na Ba?a dos Golfinhos. Entretanto, o tempo de perman?ncia dos golfinhos nesta enseada tem diminu?do e uma nova ?rea vem sendo ocupada pelos animais para a realiza??o dos mesmos comportamentos, que s?o descanso, reprodu??o e cuidados com os filhotes. Esta ?rea compreende a extremidade nordeste do Mar de Dentro da Ilha Fernando de Noronha, incluindo a ?rea defronte as praias do Meio e do Cachorro e toda a Ba?a de Santo Ant?nio e Regi?o Entre Ilhas. O presente estudo objetivou caracterizar a ocupa??o dos golfinhos e descrever as intera??es com o turismo nesta ?rea. Os dados foram coletados atrav?s de ponto fixo em 2008 e 2009. A ?rea de estudo foi dividida em sete sub?reas e os registros foram: presen?a/aus?ncia de golfinhos, tempo de perman?ncia no dia, tempo de perman?ncia em cada sub?rea, estimativa do n?mero de indiv?duos, dire??o e velocidade de deslocamento dos golfinhos, presen?a de barcos, tempo de intera??o, acompanhamento, atitude e velocidade de deslocamento das embarca??es. O tempo de perman?ncia dos golfinhos mostrou o mesmo padr?o nos dois anos do estudo, sendo a Regi?o Entre Ilhas a com maior ocupa??o. Os agrupamentos com mais de 200 indiv?duos foram os mais freq?entes, tanto em 2008 (46,2%) como em 2009 (42,3%). A dire??o preferencial de deslocamento sentido Ilha Rata e a velocidade de deslocamento lenta tamb?m mostraram o mesmo padr?o nos dois anos. A Regi?o Entre Ilhas tamb?m foi a que apresentou o maior tempo de perman?ncia dos barcos pr?ximos aos grupos de golfinhos. As embarca??es significativamente se deslocaram mais em velocidade lenta (95%) dos que em alta velocidade (5%). O cumprimento da legisla??o de prote??o aos cet?ceos ocorreu em 89,7% das 2.839 intera??es entre barcos e vii rotadores em que foi registrada esta vari?vel. Quando as embarca??es se deslocaram em velocidade lenta durante os encontros com os agrupamentos de golfinhos-rotadores, os animais tamb?m se deslocaram em velocidade lenta (n=337), significativamente mais do que os deslocamentos r?pidos (n=128) ou porpoise (n=4) (X2=318,543; p= -0,001). J? quando as embarca??es passaram r?pido pelos agrupamentos de golfinhos, observou-se diferen?a significativa entre as velocidades de deslocamentos dos golfinhos (X2=18,264; p=-0,001), entretanto, as freq??ncias de deslocamentos lentos (47%) e r?pidos (47%) foi igual, sendo a diferen?a notada com os deslocamentos em porpoise (6%), que apresentou a menor freq??ncia. Os dados indicam o estabelecimento de um novo padr?o de ocupa??o dos golfinhosrotadores em Fernando de Noronha, sendo a Regi?o Entre Ilhas de grande import?ncia para os h?bitos dos golfinhos e atualmente a principal ?rea de encontro das embarca??es com os golfinhos, mostrando a necessidade de novas medidas de conserva??o nesta ?rea
85

Social, ecological and genetic structures of bottlenose dolphins, Tursiops truncatus, in the Normano-Breton gulf and in the North-East Atlantic / Structures sociale, écologique et génétique du grand dauphin, Tursiops truncatus, dans le golfe Normand-Breton et dans l'Atlantique Nord-Est

Louis, Marie 15 July 2014 (has links)
Les patrons de structuration des espèces animales à fine et à large échelles peuvent être façonnés par des facteurs environnementaux et des traits comportementaux individuels. Les objectifs de cette thèse combinant des approches sociales, génétiques, isotopiques et morphométriques sont de décrire et comprendre i) les structures sociale, écologique et génétique de la population de grands dauphins du golfe Normand-Breton (NB) et ii) la structure de population de l'espèce à l'échelle de l'Atlantique Nord-Est (ANE). Les grands dauphins du golfe NB forment une unique population génétique qui est composée de trois ensembles sociaux et écologiques distincts. Les associations entre individus semblent être influencées par l'écologie et non par les liens de parenté. La structure génétique du grand dauphin à l'échelle de l'ANE est hiérarchique, avec deux écotypes, l'un côtier et l'autre pélagique, qui sont chacun divisé en deux populations. Les populations côtières sont issues d'une population pélagique et auraient colonisé les habitats côtiers libérés lors de la dernière déglaciation, ce qui a permis la diversification de l'espèce. Cette structure semble maintenue par les spécialisations écologiques et le comportement social des individus. Par ailleurs, l'origine pélagique des grands dauphins du golfe NB pourrait expliquer certains de leurs traits sociaux. Pour conclure, les patrons de structuration à fine et à large échelles de ce prédateur supérieur semblent influencés par les comportements sociaux et écologiques, les conditions environnementales présentes et passées ainsi que par son histoire évolutive. L'absence de différences morphologiques marquées entre les deux écotypes pourrait s'expliquer par leur divergence relativement récente ou par un faible contraste entre les habitats pélagiques et côtiers dans l'ANE. Ce travail souligne l'intérêt de combiner de multiples approches à différentes échelles temporelles et spatiales pour comprendre la structure sociale et la structure de population d'espèces mobiles et cryptiques. Ces résultats ont également des implications majeures pour la conservation, en particulier pour la définition d'unités de gestion. / Complex interactions between environmental factors and behavioral traits may shape the fine and large scale structuring patterns of animal species. The objectives of this dissertation were to describe and understand i) the fine-scale social, ecological and genetic structures of bottlenose dolphins in the Normano-Breton (NB) gulf and ii) the population structure of the species at the scale of the North-East Atlantic (NEA) by combining social, genetic, stable isotope and morphometric approaches. Coastal bottlenose dolphins in the NB gulf form a single genetic population subdivided in three social and ecological clusters. Ecology but not kinship may influence association patterns. In the NEA, bottlenose dolphin genetic structure is hierarchical. They form two ecotypes, i.e. coastal and pelagic, each of them being further divided in two populations. This genetic structure was likely triggered by past changes in the environment (i.e. deglaciation) that created ecological opportunities for diversification. Ecological specializations and social behavior may maintain genetic divergence. In turn, the pelagic origin of bottlenose dolphins in the NB gulf may explain some of their social structure traits. Thus, an interaction between social and ecological behaviors, current and past environmental conditions, and evolutionary history may drive the fine and large scale structuring patterns of this top predator. The absence of strong differences in morphology between the two ecotypes may be explained by their relatively recent divergence or by low contrasts between the pelagic and coastal habitats in the NEA. This work highlights the power of combining approaches at different temporal and spatial scales for assessing the social and population structures of highly mobile and difficult to access species. The results have also major conservation implications especially for the designation of management units.
86

The effects of physical, biological and anthropogenic noise on the occurrence of dolphins in the Pacific region of the Panama Canal

Campbell Castillo, Inez January 2014 (has links)
The main aim of this thesis was to investigate the occurrence of dolphins in Pacific waters adjacent to the Panama Canal in the context of biological, temporal and spatial factors. Acoustic data were collected at 101 sites at a range of distances and depths from the shipping region. Data were collected between March 2010 and April 2011 in a diurnal cycle over a total of 114 recording days. Received sound levels were split into 1/3 Octave bandwidths to study variation in sound pressure levels and then converted to spectrum density levels to show the sound components of the background noise in this region. Generalised Linear Models were used to relate dolphin whistle detections to temporal, spatial, environmental and acoustic variables. The major sources of background noise were biological noise from soniferous fish and snapping shrimp and anthropogenic noise from vessels characterised by mid to high frequencies produced by artisanal fishing boats. There was monthly and diurnal variation with some locations characterised by loud sounds in the mid to high frequencies at night. Whistle characteristics analysis revealed that the frequencies and range of the whistles were different to those previously reported under similar conditions. Whistles varied diurnally and in the presence of fish chorus and fishing boats. The study highlights a strong correlation between fish choruses and whistle detection. Temporal and spatial models showed that whistle detections varied monthly and in relation to fish noise and small vessel engine noise. Dolphins were distributed throughout most of the study area; however, whistle detections varied with distance from the coast. The results provide new knowledge about background noise composition in this region and provide the first information on the ecology of dolphin whistles in relation to this background noise, especially to fish chorus.
87

Ecological studies of bottlenose and humpback dolphins in Maputo Bay, southern Mozambique.

Guissamulo, Almeida Tomas. January 2008 (has links)
The ecology and population biology of bottlenose and humpback dolphins inhabiting the Maputo Bay, Southern Mozambique were studied through boat based photoidentification surveys and behavioural methods between December 1995 and December 1997. Data from preliminary surveys carried out in 1992 are also included. Bottlenose dolphins occurred throughout the year in Maputo Bay, but were sighted infrequently (36% of surveys). Their occurrence and group size were significantly larger during winter. Group size of bottlenose dolphins not differ significantly between months, daylight hours, semi-lunar tidal cycles and depth. Most identifiable bottlenose dolphin individuals had low site fidelity, but nursing females had relatively high site fidelity, implying that Maputo Bay is a nursing area. The group dynamics of bottlenose dolphins suggests a fluid (fission-fusion) social organisation. Age and sex appears to influence the degree of association between individuals. An influx of bottlenose dolphins occurred during winter and influenced group size and occurrence. Bottlenose dolphins occurred in restricted areas of the Bay, preferring the north eastern area (the pass between the Bay and the Ocean), and along the 3 km strip from the east coast of Inhaca Island. Their distribution here did not vary with depth, although they did not occur in intertidal areas. Feeding dominated both frequency and proportion of time of bottlenose dolphin behaviour. Social behaviour accounted for a small proportion of time (10%) and was greater in open unsheltered areas. Neither season, nor depth, nor daylight, nor tides influenced the proportion of time allocated to the types of behaviours. Non directional movement occurred on most of the sightings of bottlenose dolphins, but smaller groups of dolphins moved inshore at high tide late in the afternoon. Few bottlenose dolphin births were observed and the numbers of animals born varied between years. Recruitment rates at six months and one year were low and mortality rates of calves appeared high, but were probably inaccurate because the fate of mother-calf pairs that left the area could not be established. Population estimates of the bottlenose dolphins varied between 170 and 526 individuals. The precision of these estimates was poor, because of high proportion of transient individuals which almost certainly violated some model assumptions. Humpback dolphins occurred throughout the year in Maputo Bay, but were sighted infrequently (21% of surveys). The occurrence and group size of humpback dolphins were not influenced by season, months, daylight, semi-lunar tidal cycles and depth. Groups of humpback dolphins in Maputo Bay were the largest observed along the east coast of Southern Africa. Most identified humpback dolphin individuals showed low site fidelity, but a relatively high proportion of individuals (including nursing females) had high site fidelity. Humpback dolphin groups had a fluid (fission- fusion) social organisation, but there was a large proportion of stable associations between resident individuals. Age and sex appears to influence the degree of association between individuals. An influx of humpback dolphin individuals occurred during summer but did not change group size or occurrence, suggesting the occurrence of an outflux of other individuals. Humpback dolphins in the Bay ranged between the deep north eastern Maputo Bay to the southern intertidal areas. Most sightings occurred within 1 km from shore along the eastern coast of Inhaca Island, at variable depth. Humpback dolphins spent more time feeding (57%) and travelling (30%) than socializing and resting, because of their movements between extensive intertidal areas and deep channels. Social behaviour contributed a small proportion of time (10%), but increased when humpback dolphins moved towards and within shallow sheltered areas. Neither season, nor depth, nor daylight, nor tides influenced the proportion of time allocated to the types of behaviours of this species. Non directional movement occurred on most of the sightings of humpback dolphins, thought this was significantly influenced by diurnal tides. Few humpback dolphin births were observed and their numbers varied between years. Recruitment rates at six months and one year were low and mortality rates appeared high, but were probably inaccurate because the fate of mother-calf pairs that left the area could not be established. Population estimates of humpback dolphins varied between 105 and 308 individuals, but their precision was poor, because of a high proportion of transient individuals which almost certainly violated some model assumptions. Maputo Bay is a feeding, breeding and nursing area for bottlenose and humpback dolphins. These species are threatened by intense fishing activity, habitat degradation, coastal development and disturbance by powerboats and other activities (tourism, port) carried out in and around Maputo Bay. Their low estimated growth rates imply the implementation of precautionary conservation measures. The actual distribution of these species may reflect the deterioration of the habitats in the western part of the Bay. A coastal zone management plan to address environmental problems affecting the dolphin species need to be formulated and implemented. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.
88

Genetic characterisation and social structure of the East Scotland population of bottlenose dolphins (Tursiops truncatus)

Islas, Valentina January 2010 (has links)
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.
89

Whale and dolphin watching: should dolphin watching in Hong Kong be regulated?

Lam, Hung, Helina., 林洪. January 2000 (has links)
published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management
90

Site Fidelity Assessment of Atlantic Bottlenose Dolphins (Tursiops truncatus) Following Large-Scale Emigration of Sympatric Atlantic Spotted Dolphins (Stenella frontalis) in the Bahamas

Unknown Date (has links)
Two sympatric species of dolphins (Atlantic spotted dolphins, Stenella frontalis and Atlantic bottlenose dolphins, Tursiops truncatus) have been long-term residents to Little Bahama Bank. This study assessed whether there was a change in residence patterns or diurnal foraging depths of bottlenose dolphins following a large emigration event in the resident spotted dolphin community on this sandbank. Photo-identification was used to identify individual bottlenose dolphins and compare pooled years before (2010-2012) and after (2013-2015) the spotted dolphin emigration. The identified community size and overall residency of the bottlenose dolphins remained similar, although two bottlenose dolphins emigrated over deep water to the site spotted dolphins emigrated. Bottlenose dolphins diurnally fed in shallower water but remained in the same geographic foraging locations. Reasons remain unknown for this depth change, but potential changes in the productivity of primary bottlenose dolphin foraging habitats or reduction of spotted dolphins from shallower depths remain possibilities. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection

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