No description available.

The ability of adult wild Atlantic spotted dolphins (Stenella frontalis) to synchronize vocalizations and behaviors has been found to be a key factor in overcoming much larger bottlenose dolphins during interspecies aggression (Cusick & Herzing, 2014). Furthermore, an adult baseline of behaviors and vocalizations during aggressive events containing synchrony has been established (Myers, Herzing, & Bjorklund, 2017). The present study examines juvenile aggression that contains bouts of synchrony to look at the development of this valuable skill. Differences of duration between adult and juvenile synchronous bouts, lag sequential analyses, frequencies of behavioral classes depending on the age class of the aggressor-recipient dynamic, differences in the frequencies of behavioral classes depending on the synchronous state and aggressorrecipient dynamic, and differences in behavioral classes exhibited by adults and juveniles during different synchronous states were analyzed. Adults, across group size, were able to maintain physical synchrony for a longer duration. Juveniles were often in loose synchronous groups before forming into a tight synchronous group as seen in adult synchrony. Vocal synchrony during adult aggression in terms of synchronized squawks were longer in duration than vocal synchrony during juvenile aggression. Juveniles used more pursuit behaviors during aggression, which indicates practice of a behavior that was found to be the most frequently used in interspecies aggression (Volker, 2016). Additionally, when adults were present in juvenile aggression, they used fewer aggressive behavioral classes demonstrating self-handicapping based on their opponent. This illustrates that there is a learning period for both vocal and physical synchrony for juvenile dolphins and that juvenile aggression, or play-fighting, is an important aspect of the development of these skills. This study is the first to describe juvenile synchrony in a population of wild Atlantic spotted dolphins. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

Thesis (Ph.D.)--Memorial University of Newfoundland, 2005. / Includes bibliographical references.

Numerous populations of wild Atlantic salmon have declined in recent years. The Atlantic salmon in Girnock Burn, an upland spate tributary of the River Dee, Scotland have been monitored intensely by government scientists since 1966. The burn is equipped with upstream and downstream traps, which have enabled monitoring of juveniles leaving the burn and adults returning to it since 1966. Recently, due to a decline in numbers of female returns, a supportive breeding program was instigated. Using microsatellite-based DNA profiling, this study exploited existing and novel tissue samples to investigate aspects of Atlantic salmon biology and conservation. A panel of up to 12, mainly highly polymorphic, microsatellite loci were employed to derive allele frequency data and to resolve parentage in egg, parr, smolt and anadromous adult samples taken between 1991 and 2004. Genotyping error was investigated and rectified where possible. Overall, the detected error was low (c.0.5%), providing confidence in subsequent population and parentage analyses. The error rate involved in estimating the age of salmon in Girnock Burn from scale readings was also estimated (c.2-8%). A study of the dynamics of natural spawning, based on the parentage of parr, confirmed that multiple matings by anadromous returns of both sexes were prevalent. Not all anadromous returns were apparently successful spawners; data from parr and existing redd samples failed to detect a contribution from 35% of males and 29% of females. An important aspect of the work was to determine the success of the supportive breeding program. Results showed that, in comparison to natural spawning, the program gave a more complete and even representation of adult spawners in offspring. In addition, there was no detectable difference in the output (number of smolts) of the two schemes when the number of eggs used in each was taken into account. The distribution of juvenile kin (parr aged 1+) within the burn was determined, which revealed clustering of full and half sib groups. This was found to impact on standard population genetic analyses. Adjacent samples (n = 50), each sampled over a c.1.5 km stretch of river were shown to exhibit significant allelic differentiation, while samples from individuals selected at random over a 7.5km stretch did not. Parentage analysis of adult returns showed that the number of returns likely to be philopatric was higher than would be predicted solely from physical tagging data. This was attributed to ‘leakage’ of the downstream parr/smolt trap. An initial investigation into the role of mature parr in adaptation of populations to the environment was made, although sire type (i.e. anadromous male or mature parr) was not found to affect survival in the freshwater environment in this case. More research into this aspect is warranted, particularly with the possible impact of predicted climate change on male parr maturity. A comparison of genetic diversity through time (measured by allelic richness) revealed no detectable change between 1991 and 2004. Estimates of the effective population size using different genetic (temporal) methods were associated with a large degree of uncertainty, and were surprisingly high (ranging from 595 to 1992) c.f. demographic based estimates (ranging from 95 to 144), which was likely to be due in part to violation of assumptions made in the calculations. These findings have highlighted a range of avenues for future lines of research, should aid in the management of Atlantic salmon within Girnock Burn and assist in the design of sampling regimes.

No description available.

No description available.

Graduation date: 1982

Thesis (Ph. D.), Memorial University of Newfoundland, 1999. / Bibliography: p. 163-177.

Thesis (M.Sc.)--Memorial University of Newfoundland, 1999. / Restricted until November 2001. Includes bibliographical references.

Bibliography: pages 45-55. / Eleven gravity cores from the continental margin off Eire and Land's End (SW England) were examined and found to document the major trends of the Late Pleistocene climate. Several stratigraphic indicators; - carbonate content, sediment texture, grain size, composition, nature of terrigenous components, ice-rafted debris and foraminiferal diversity were examined and show that the glacial history of the study area can be closely correlated with the palaeoclimatic evolution of the adjacent European shelf. Sediments deposited during Late Pleistocene glacial conditions show the following characteristics when compared to the surface sediments deposited under Holocene interglacial conditions: an increase in the quantity of ice-rafted debris and percentage of mica, and a notable increase in the degree of frosting and pitting of the quartz grains. Overall grain size was finer resulting in a silty sediment package. Sedimentologically the cores fall into two groups (1 and 2). The major difference being that Group 1 (located on the Pendragon Escarpment) received increased quantities of fine silts from a 'shelf spill-over' mechanism operating on the Fastnet and Western Approaches Basins, during glacial regressions. All sediment samples displayed polymodal characteristics reflecting the interaction of several different physical processes e.g. ice-rafting, contour currents etc. Striking variations in the populations of planktonic foraminifera were noted, alternating between Arctic and Sub-Arctic assemblages, reflecting the waxing and waning of glacial activity. The coccolith-carbonate minima correlate with the Arctic-fauna maxima and the ¹⁸O/¹⁶O maxima of the oxygen-isotope curves. Foraminiferal-test analysis (ratio of whole foraminifera fragmented foraminifera) revealed that no correlation existed with any of the other parameters analysed. However, the cores were severely affected by the presence of bottom currents which were strong enough to remove the fragmented tests. Parallellaminated contourites and evidence of erosion were noted in all cores. Ten cores penetrated sediments deposited during the last glacial maximum of 20,000 B.P - 18,000 B.P. near the 75cm depth mark (Core 1865 was too short to reach such sediments). However sediments reflecting the 11,000 B.P glacial readvance, detected at around the 25cm mark, were not as clearly represented. Bioturbation has smoothed the climatic record throughout the lengths of these cores and has also suppressed the high-frequency oscillations (<10³ B.P).