Photoidentification surveys of bottlenose dolphins (Tursiops truncatus) were conducted from December of 2002 through December of 2003 in Chocolate Bay, Texas, and the adjacent Gulf of Mexico area. The research represented the continuation of an ongoing study of the dolphins of this area. Behavioral sampling was carried out on a small resident community of dolphins that seasonally reside in Chocolate Bay, as well as on dolphins found along the gulf coastline. Resident dolphins had a daily behavioral pattern, with peaks of foraging activity in the morning, traveling at midday, and socializing in late afternoon. Gulf dolphins had small mean group sizes of 3.4 and were primarily observed foraging and traveling, with little socializing. When resident and gulf dolphins interacted, the mean group size increased to 12 and the proportion of social behavior increased. Association indices demonstrated no long-lasting associations among adult male dolphins, while strong associations existed between several females. Females revealed two patterns of association; they were either members of a female band with other mother-calf pairs, or were solitary with no strong affiliations with any dolphins other than their calf. Males seemed to disperse upon maturation, which maintained the community size of approximately 35 animals. Behavioral evidence indicates the resident community is matrilinealy related and composed largely of adult females and their offspring. A few adult males remain resident, while most young males disperse from the community and may rove among the gulf population. Although mating probably occurs between resident and gulf dolphins, sources of both maternity and paternity for residents need to be determined, and further behavioral work needs to be carried out to support this hypothesis.

Photoidentification surveys of bottlenose dolphins (Tursiops truncatus) were conducted from December of 2002 through December of 2003 in Chocolate Bay, Texas, and the adjacent Gulf of Mexico area. The research represented the continuation of an ongoing study of the dolphins of this area. Behavioral sampling was carried out on a small resident community of dolphins that seasonally reside in Chocolate Bay, as well as on dolphins found along the gulf coastline. Resident dolphins had a daily behavioral pattern, with peaks of foraging activity in the morning, traveling at midday, and socializing in late afternoon. Gulf dolphins had small mean group sizes of 3.4 and were primarily observed foraging and traveling, with little socializing. When resident and gulf dolphins interacted, the mean group size increased to 12 and the proportion of social behavior increased. Association indices demonstrated no long-lasting associations among adult male dolphins, while strong associations existed between several females. Females revealed two patterns of association; they were either members of a female band with other mother-calf pairs, or were solitary with no strong affiliations with any dolphins other than their calf. Males seemed to disperse upon maturation, which maintained the community size of approximately 35 animals. Behavioral evidence indicates the resident community is matrilinealy related and composed largely of adult females and their offspring. A few adult males remain resident, while most young males disperse from the community and may rove among the gulf population. Although mating probably occurs between resident and gulf dolphins, sources of both maternity and paternity for residents need to be determined, and further behavioral work needs to be carried out to support this hypothesis.

Bottlenose dolphins of the Kvarnerić (NE Adriatic Sea) live in an area of increasing human impact, through tourism and small-scale fisheries. This thesis aimed to assess the status of the local population and to inform managers on factors affecting their distribution and abundance, using data from 1995-2003. Habitat modelling indicated a significant negative impact of proximity to the main ‘marine highway’ and to marine petrol stations. Evidence was found that dolphins may recently have reached a tolerance limit to the number of boats using the area and that they remember crowded areas from one year to the next. Dolphin presence was positively related to particular depths and trawling areas. Apparent adult survival rate was estimated to be significantly lower than for any other bottlenose dolphin population and first year calf survival was also low. A decreasing trend in fecundity rate was found. The population showed a considerable rate of non-random temporary emigration from the study area. The estimated size of the population was small and similar to two other European bottlenose dolphin populations (Moray Firth in Scotland and Shannon Estuary in Ireland). A significant decrease in abundance of about 39% from 1995 was estimated. PVA confirmed the importance of female adult survival to population viability and indicated that the current rate of human-induced mortality is unsustainable. Local extinction risk within three generations was estimated to be high (35%). Applying the IUCN Red List Criteria, the Kvarnerić population should be listed as Endangered under Criterion C and E. This study gives an important insight into the ecology of Adriatic bottlenose dolphins and indicates the need for a regionally and locally synergistic approach to conserve this population.

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.

The heterogeneous landscape of Florida Bay provides habitats for a variety of predators and prey. This dissertation examined the bottom-up transfer of affects from environmental variability through prey composition up to competition and predation affects on top predator distribution and foraging ecology in Florida Bay. Line transect surveys for bottlenose dolphins and seabirds were conducted in Florida Bay during the summer months of 2002 - 2005. Photo-identification techniques were implemented to identify individual dolphins. Synoptic with this survey effort, habitat characteristics (temperature, salinity, dissolved oxygen, turbidity, chlorophyll a, depth and bottom type) and prey composition (bottom trawl or gillnet) were sampled. Comparison of envelope maps from generalized additive models determined that predictive capacity of dolphin habitat did not improve by incorporating fish distribution data. However, models of dolphin distribution based solely on environmental proxies of fish distribution resulted in high predictive capacity. During the 2005 summer, shark distribution was sampled using a longline. The abundance of sharks was only correlated to fish catch from trawls on a regional scale. Larger sharks, of species that may threaten dolphins, were only caught in the Gulf zone of the Bay. Analysis of dolphin distribution revealed high individual site and foraging tactic fidelity. Dolphins were spatially coincident with habitat characteristics that encouraged the use of each individual's preferred foraging tactic. Depth was identified as the primary variable determining dolphin foraging tactic choice. Depth plays a significant role in the benthic composition of Florida Bay, which subsequently impacts prey communities and affects dolphin distribution, foraging and social ecology. Ordinations determined that fish distribution was also principally affected by depth and bottom type. Shallow environments frequently corresponded with mudbank habitat (depth < 1m) where the sighting rates of seabirds (cormorants, osprey, pelicans, terns) and foraging dolphins peaked. In conclusion, subtle relief in South Florida's bedrock topography dramatically affect benthic composition within Florida Bay, providing patchy habitats for prey and predators. The Florida Bay ecosystem will change with expected sea level rise, including spatial shifts of mudbank habitats. Top predator populations in Florida Bay will be forced to modify their distribution and foraging ecology accordingly. / Dissertation

No description available.

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.

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.

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.

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.