Thesis (Ph. D.)--Australian National University, 2001. / Title from PDF title page (viewed May 8, 2005). Consists of reprints of thirteen published papers, some co-authored with others, plus an introductory chapter, two unpublished manuscripts, and a conclusion. Includes bibliographical references.

The Australian fur seal (Arctocephalus pusillus doriferus) population has displayed a relatively slow rate of recovery since being hunted by commercial sealers during the early 19th century. Despite this, population abundance doubled in the past 2 – 3 decades, indicating that the population growth rate has recently increased. Yet, the factors influencing the population’s dynamics are poorly understood, primarily because basic demographic rates are unknown. / Female age, survival, fecundity, breeding and physiology were studied at Kanowna Island, Bass Strait, Australia, between 2003 – 2006 by conducting censuses and captures (n = 294). Mark-recapture estimates of pup production were used to validate direct pup counts, allowing a 9-year dataset to be used for calculation of the population growth rate (2.2% p.a.) and investigation of environmental influences on reproductive success. Annual pup production (x = 3108) was synchronous, with 90% of births occurring within 28 days of the median birth date of 23 November. Births occurred earlier in years when pup production and female body condition were high and these factors were correlated with local oceanographic indicators, suggesting that reproductive success is constrained by environmentally-mediated nutritional stress. / Pregnancy was assessed by blood plasma progesterone radioimmunoassay and the pupping status of the same females was observed during breeding season. Despite high mid-gestation pregnancy rates (x = 84%), the birth rate was lower than in other fur seals (x = 53%), suggesting that late-term abortion is common. Lactating females were less likely to pup, indicating that nutrition may be insufficient to support concurrent lactation and gestation. / Age and morphometric data were used to construct body growth, age structure and survivorship models. Adult female survival rates were similar to those of other fur seals (x = 88.5%). A life table was constructed and its age-specific survival and fecundity rates used in a Leslie-matrix model to project the population growth rate (2.2% p.a.) and determine the relative influence of each parameter. The abundance of female non-pups was 6 times greater than that of female pups, which is approximately 50% higher than previous conversion factors used to extrapolate population abundance from pup censuses in Australian fur seals. However, if the non-pup sex ratios of other otariids are considered, the pup:population conversion factor is 4.5. / Compared to a study performed before the recent population increase, the modern population displays similar body growth and fecundity rates but higher survival rates. This suggests that recent population growth resulted from a relaxation of hunting and/or predation mortality rather than from increased food availability. The low population growth rate is attributed to a low birth rate associated with nutritional stress, yet despite this, body growth occurs rapidly. Such characteristics are typical of sea lions rather than fur seals, perhaps because Australian fur seals employ the typical sea lion strategy of using benthic foraging to exploit a continental shelf habitat. The effect of ecological niche on population dynamics in the Otariidae is discussed.

Thesis (M.A.)--Virginia Polytechnic Institute and State University, 1991. / Vita. Abstract. Includes bibliographical references (leaves 123-127). Also available via the Internet.

Thesis (Ph. D.)--University of California, Davis, 2004. / Degree granted in Molecular, Cellular, and Integrative Physiology. Includes bibliographical references. Also available via the World Wide Web. (Restricted to UC campuses)

A conceptual model is proposed that describes the dynamics of the Pribilof Islands North Pacific fur seal (Callorhinus ursinus). It is suggested that fur seals are regulated most strongly at population levels close to the limits set by the availabilities of food and breeding space. Population growth appears to be primarily regulated by changes in the rates of survival, reproduction, and dispersal of young animals. The proposed conceptual model is used to shape a mathematical formulation that incorporates basic fur seal life history features. The simulation analysis is able to explain the decline of the Pribilof Islands population by reconstructing pup estimates and counts of adult males over the period 1950 to 1980. Simulation results show that commercial female harvesting and a series of poor juvenile survival rates were responsible for the observed decline in pup production on Saint Paul Island. The lower number of bulls counted during the last two decades can be accounted for if adult male survival was higher during the 1950s. The decline in adult male survival, possibly due to debris entanglement, does not appear to be equally true of females. The major driving variable of the fur seal system and the key factor that accounts for the overall decline of the Pribilof herd is the survival of juveniles. In this regard, the continued population decline through the 1980s appears to be maintained by exogenous factors that are independent of current management practices. Model results are considered reliable if simulation parameters (particularly adult survival) contain little error. A detailed procedure for analysing the sensitivity of model output to errors in simulation parameters is described in an adjoining appendix as is a revised procedure for estimating the survival of juvenile fur seals. The thesis concludes with recommendations for future research. / Science, Faculty of / Zoology, Department of / Graduate

Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 97-117).

Thesis (M.S.)--University of North Carolina Wilmington, 2009. / Title from PDF title page (February 16, 2010) Includes bibliographical references (p. 82-86)

The demand by ecotourism for easily accessible wildlife encounters has increased the need for regulations to minimise negative effects of tourism on towards marine mammals. High levels of human interaction could have serious consequences for recovering populations of New Zealand fur seals (Arctocephalus forsteri). By monitoring behavioural shifts in reactions to human disturbance, the aim of this study was to determine how disturbance by tourism is affecting the behaviour of the New Zealand fur seals. Fur seal breeding colonies, haul-outs, and a pup nursery were studied on the South Island to determine the level of disturbance. Data collected in this study can be used towards improving monitoring regimes to mitigate negative effects of anthropogenic disturbance. I first used behavioural observations to assess a seal’s behaviour in response to different types of tourist activities. Next, I examined changes in New Zealand fur seal behaviour as a result of visits to colonies by tourist boats. To quantify the response of fur seals to tourist boats, experimental boat approaches were conducted using a before, during, and after instantaneous scan sampling method at two breeding colonies (one with high vessel traffic and one with none). Impact of noise was also investigated using a loud speaker to mimic local harbour tours. Lastly, behavioural observations on seal pups at a nursery were conducted comparing pup behaviour in the presence and absence of tourism along with variable intensities of tourist behaviour. My observations suggest that seal behaviour was significantly different between sites with and without tourist visits. The type of tourism had a significant effect on the behavioural state of seals, with animals more active when there were people walking in the colonies. There were also signs of habituation in some of the study colonies. Since each colony varied in the type of tourism it experienced, it is possible that it is not only the level of tourism that is important but also the type of tourism that has a significant role in eliciting short-term behavioural shifts. Observations from a tour boat revealed an increase in the percentage of seals reacting when vessels were close to the shore. This distance effect was overridden and reactions were greater, however, when tours included commentary via an external speaker. The effects of both distance and noises were significantly different between colonies with high and low levels of tourist visits. Due to the overlap of peak tourist visits with fur seal breeding season, these animals are at their most vulnerable when companies are in peak operation. Finally, as with adults, pup behaviour was also significantly affected by tourism presence. Periods of inactivity and awareness increased in the presence of tourists, which is indicative of disruption of “play” and movement towards more vigilant behaviour. Despite the significant effects of tourist visits I found in this study, there was large variation in the degree of responses in different populations of the fur seal. This variation is thought to be due, in part, by the level of desensitisation, especially at locations with high or continual tourism pressures. This study also provides evidence that fur seal pups subject to human disturbance will alter their behaviour, shifting from active (when people are not around) to inactive and more aware (with increased disturbance). The results presented suggest such visits are not without consequences and that animals can be disturbed by human interactions. Therefore, measures should be taken at all seal colonies used in tourism ventures to mitigate any negative long-term effect on the fur seal populations.

Thesis (M.F.A.)--Montana State University--Bozeman, 2005. / Typescript. Chairperson, Graduate Committee: Ronald Tobias. Includes DVD. Includes bibliographical references (leaves 29-31).

This thesis builds a demographic profile of the Northern Fur Seal (NFS) population being consumed at DfSi-4 and DfSj-23 to determine if a NFS rookery existed within close proximity to both sites. A demographic profile of the death assemblages found at each site was built using visual identification, a non-linear growth curve algorithm developed by Michael Etnier (2002) and ancient DNA analysis. This study uses the demographic profile to evaluate the existence of a NFS rookery within the Barkley Sound area. Ultimately the existence of a rookery depends on demonstrating the existence of four age categories: fetal/newborn, juvenile, adult and adult male. Results indicate that a rookery likely existed near DfSj-24A, but there is much less certainty for DfSi-4. Further inquiry is now possible into the economic and ecological relationships that existed between the Toquaht and the NFS within the Barkley Sound area. / February 2016