I examined summer home range use of Altantic spotted dolphins in the Bahamas from 1991-2004. Home ranges for 86 dolphins using the 95% Fixed Kernel Density (FKD) estimator averages 62.o km2+=22.96 km2 and ranged from 24.8 km2 to 148.4 km2. Older animals and males had the largest ranges. Home range size did not vary with female reproductive status. core areas were defined by the 50% FKD contour and averaged 10.32 km2 +=5.47 km2. Habitat use was different between reproductive states for females. Non-reproductively active (NRA) females used deeped habitat. Behavioral use of the home range varied spatially. The core area was an important foraging area for males and reproductively active females. NRA females foraged more outside their core area compared to the core area. / by Bethany Augliere. / Thesis (M.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

Understanding gene flow, diversity, and dispersal patterns is important for predicting effects of natural events and anthropogenic activities on dolphin populations. With the very recent exceptions of false killer whales (Pseudorca crassidens), spinner dolphins (Stenella longirostris), and common bottlenose dolphins (Tursiops truncatus), Hawaiian odontocete species are managed as single stocks within the U.S. Hawaiian Exclusive Economic Zone. These exceptions are a result of recent studies that have indicated that some species have populations that show fidelity to individual islands or groups of islands, resulting in genetic differentiation, often with management implications. The first part of my study (following the introductory chapter) focused on population structure of pantropical spotted dolphins (Stenella attenuata) near the Hawaiian Islands. Because of the level of human interaction, pantropical spotted dolphin populations need to be defined accurately to be managed in a way that will avoid local population losses, especially given that the commercial and recreational troll fisheries near the islands "fish on dolphins" to catch tuna. I analyzed genetic samples for mtDNA and microsatellite loci from four island regions: Hawai'i, the 4-islands area, O'ahu, and Kaua'i/Ni'ihau. My results support genetic differentiation among the regions of Hawai'i, the 4-islands area, and O'ahu and suggest that pantropical spotted dolphins near Kaua'i/Ni'ihau are likely transient and in very low numbers. There was no strong evidence to support sex-biased dispersal or group fidelity. Possibly, differentiation is mediated by behavior adapted to differing habitat types. From a management perspective, spinner and bottlenose dolphin populations near the Hawaiian Islands have been split into separate stocks for management based on levels of genetic differentiation similar to those found for pantropical spotted dolphins. These precedents suggest that comparable action should be taken to split pantropical spotted dolphin stocks near the Hawaiian Islands. Most population studies rely heavily upon fixation indicies like FST to determine whether populations are genetically differentiated. When FST values are low but significantly different from zero, it can be difficult to interpret the biological significance of these values. As part of my study, I suggest that one way to evaluate whether small FST values indicate significant differentiation is to compare FST values with other populations considered to be separate based on factors such as extreme distance or morphological differences. I examined pantropical spotted dolphins from the coastal and offshore Eastern Tropical Pacificm (ETP), Hawaiian Islands, and China/Taiwan to examine the utility of comparing FST values across separate populations. Among Hawaiian Island regions, FST values are significantly different from zero but small. The comparison of these FST values with more distant populations in the ETP and China/Taiwan indicated that differences among Hawaiian Island regions were similar in magnitude to those found between the offshore and coastal ETP sub-species, but smaller than between the Hawaiian Island regions and the other regions examined. This suggests a level of reproductive isolation among the Hawaiian Islands regions that is comparable to that of offshore and coastal ETP populations, and supports the value of fixation index comparisons in evaluating differentiation among putative populations. My results suggest that assigning specific numerical baseline FST values may not always be biologically meaningful but that determining whether related populations with geographic or other separation show a preponderance of similar, lower, or higher fixation index values can help evaluate whether genetic differences among sympatric or parapatric groups warrants designating them as separate populations for management. Lastly, I explore whether the fast evolving mtDNA control region may be more suited to phylogenetic comparisons among the Stenella than slower evolving gene regions and whether the small number of haplotypes generally used in phylogenetic analyses is adequate for defining relationships among dolphins. Usually, slow evolving regions, such as gene regions, are used in phylogenetic analyses because species and genera have been isolated long enough for variation to have accumulated in such regions but not so long that many reversals (i.e. a mutational change in sequence that later changes back to the original sequence) have occured. The mtDNA control region is typically used for population genetic comparisons rather than phylogenetic comparisons because it is considered to be a fast evolving region. Historically, dolphin phylogeny has been examined using gene regions, which have resulted in ambiguous and unexpected relationships. However, the lack of variation in the mtDNA control region for pantropical spotted dolphin populations and the fact that recent studies have found that the mtDNA control region in cetaceans evolves at about one quarter the rate of other mammals, raises the question as to whether this region would be better suited to phylogenetic studies for the Stenella (and potentially other dolphin species). In comparing 346 haplotypes from five species of Stenella world-wide, I found that the mtDNA control region is probably not a good region to use for phylogenetic analyses, and that even faster evolving regions might perform better. The differences in the mtDNA control region were not sufficient to distinguish clear relationships among the Stenella. I also found that when subsets of haplotypes chosen at random were compared, the results differed among comparisons, suggesting that there is value in using more than the usual one or two haplotypes when making phylogentic comparisons. Given the recent increases in sequence availability (e.g. GenBank) and computing power, researchers should strongly consider using many haplotypes from a variety of populations in their phylogenetic comparisons.

Demographic changes, through immigration/emigration (or death) can affect the social and community structure of a population. This study reports on the effects of demographic changes following 2 intense hurricanes on two sympatric delphinid species: Atlantic bottlenose dolphins, Tursiops truncatus, and Atlantic spotted dolphins Stenella frontalis. Thirty percent of the bottlenose population was lost after the hurricanes, with an influx of roughly the same number of immigrants. The stable community split into two cohesive units. Preferences in association in relation to reproductive status and sex remained. Immigrants assimilated well into the population, especially males. There is a conflict of interest between resident males and females in accepting immigrants and often females find more resistance than males. Long-term analysis of spotted dolphins revealed a community structure defined by long-term site fidelity, natal philopatry of both sexes and three social clusters. / Female associations were influenced by reproductive status and social familiarity within clusters. Males formed long-term alliances and shorter-term coalitions. Some movement between clusters occurred. Alliance formation crystallized in adulthood. Mating strategies and sex were the primary factors shaping social structure. Thirty-six percent of the spotted dolphin population was lost after the hurricanes with no influx of immigrants. The spotted dolphin community differed little from long-term analysis, including definitive social clusters and sex preferences. Social cohesion increased within units and across age classes. Some juveniles had associations of alliance level. Loss of individuals resulted in subtle changes in social structure. Interspecies associations reveal striking differences in association patterns between species. Group sizes and re-sightings of spotted dolphins were larger than for bottlenose dolphins, particularly for aggressive encounters. / Male alliances and coalitions were prevalent for spotted dolphins, but not for bottlenose dolphins. After the hurricanes lower re-sighting and group sizes for spotted dolphin males and less aggressive behavior documented, indicates a re-structuring period of relationships between the species. This study shows that environmental variations may alter the structure of mammal societies through demographic upheaval and survival of populations may depend on their social structure and the social adaptability of the species. / by Cindy Rogers Elliser. / Thesis (Ph.D.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.

This study investigated a resident community of Atlantic spotted dolphins (Stenella frontalis) on Little Bahama Bank (LBB) in the Bahamas utilizing a noninvasive molecular approach. Genetic template material was collected and extracted from fecal material of S. frontalis. Fine-scale population structure was found within LBB according to mitochondrial DNA (mtDNA) and microsatellites (Fst = 0.25317, P < 0.0001 and Fst = 0.04491, P < 0.0001, respectively). Three main social clusters (North, Central, South/Roam) exist on LBB and all clusters were found to be genetically distinct according to microsatellite analyses. Mitochondrial haplotypes revealed North and South/Roam were not differentiated, but Central was different from both. When separated by sex, males were less genetically structured than females. Males showed no evidence of structure according to Ost or Rst. / Females of all clusters were differentiated according to microsatellites whereas mtDNA revealed the same pattern in females as was seen for the total population. The structuring patterns of the sexes clearly indicate a pattern of male dispersal and female philopatry for the LBB population. Genetic investigation of mating revealed patterns in the mating system of S. frontalis on LBB. Genotypes of females and offspring were analyzed and revealed that more than two males were required to explain the progeny arrays, indicating promiscuous mating among females. In addition, paternity assessment assigned seven males as fathers to ten of 29 mother-calf pairs. A pattern of reproductive skew according to age was revealed because reproductively successful males were in the oldest age class at the estimated time of conception of the calves. / Patterns in social cluster mating revealed that males from the Central cluster sired offspring with females from both the Central and North clusters, while Roaming males sired offspring with South and Central females indicating that males mate within their social cluster or with females from the next closest cluster. The study has important implications for cetacean research, specifically delphinids. Fine-scale population structure and mating patterns of male and female S. frontalis were revealed through noninvasive methodology presenting a valuable genetic framework with which to support ongoing investigations of life history, behavior, communication and social structure. / by Michelle Lynn Green. / Vita. / Thesis (Ph.D.)--Florida Atlantic University, 2008. / Includes bibliography. / Electronic reproduction. Boca Raton, FL : 2008 Mode of access: World Wide Web.

The Major Histocompatibility Complex (MHC) encodes proteins critical to the vertebrate immune response; therefore MHC diversity is an indicator of population health. I have (1) Isolated exon 2 of the class II gene DQA in Tursiops truncatus in the North Indian River Lagoon (IRL) (n=17), South IRL (n=29) and adjacent Atlantic waters (n=20), (2) assessed genetic variability between groups, (3) developed a method to genotype individuals, (4) typed 11 unique alleles in 66 individuals, (5) detected geographic patterns of diversity between estuarine and coastal individuals (FST=0.1255, p<0.05), (6) found evidence of positive selection centered in the binding pockets P1, P6 and P9 of the peptide binding region (w=2.08), (7) found that patterns of polymorphism did not closely match patterns of diversity in neutral markers, (8) performed a pilot study with Orcinus orca. The initial findings highlight the need for further comparative work and suggest that silent mutations are not neutral. / by Tatiana Ferrer. / Thesis (M.S.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.