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The effects of tourism on the behaviour of the New Zealand fur seal (Arctocephalus forsteri)Cate, Jenipher Rose January 2013 (has links)
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.
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Seasonal and colony differences in the foraging ecology of New Zealand fur seals (Arctocephalus forsteri).Baylis, Alastair M.M. January 2008 (has links)
The New Zealand fur seal (Arctocephalus forsteri) is the most abundant fur seal species in the Australian-New Zealand region. Approximately 85 % of Australia’s population of New Zealand fur seals reside in the state of South Australia. As a result of their abundance and size, it has been estimated that the New Zealand fur seal population in South Australia consumes the greatest biomass of resources of all marine mammal and seabird species. However, despite the importance of New Zealand fur seals as top predators, our understanding of their foraging ecology in South Australia is limited. In order to better understand the habitat utilized and the diet of New Zealand fur seals, this study explores the foraging ecology of lactating seals from four primary colonies in South Australia, which account for ~ 78 % of the Australian population. These colonies are Cape Gantheaume (36о04’S, 137о27’E) and Cape du Couedic (36о03’S, 136о42’E) on Kangaroo Island; North Neptune Island (35о13’S, 136о03’E) and Liguanea Island (34о59’S, 135о37’E). I start this study by assessing the seasonal variation in foraging location and dive behaviour of lactating New Zealand fur seals from Cape Gantheaume. 18 seals were fitted with satellite transmitters and time depth recorders (TDRs). The presence of thermoclines (derived from TDRs), were used as a surrogate measure of upwelling activity in continental shelf habitats. During the austral autumn 80 % of lactating fur seals foraged on the continental shelf (114 ± 44 km from the colony), in a region associated with a seasonal coastal upwelling system, the Bonney upwelling. In contrast, during winter months seals predominantly foraged in oceanic waters (62 %), in a region associated with the Subtropical Front (460 ± 138 km from the colony). Results suggested that lactating New Zealand fur seals shift their foraging location from continental shelf to oceanic habitats, in response to a seasonal decline in continental shelf productivity, attributed to the cessation of the Bonney upwelling in autumn. To study inter-colony differences in foraging locations, 21 New Zealand fur seals were satellite tracked from four colonies within close proximity (46 km – 200km apart). Seals initiated foraging trips on a colony-specific bearing (Cape Gantheaume 141 ± 33º, Cape du Couedic 186 ± 12º, North Neptune Island 200 ± 23º and Liguanea Island 234 ± 69º), and recorded little overlap between colony-specific foraging areas. The distribution of colony-specific foraging grounds appeared to be influenced by the proximity of colonies to predictable local upwelling features, as well as a distant oceanic frontal zone, the Subtropical Front. Foraging site fidelity and route-choice was further assessed by comparing site fidelity between continental shelf and oceanic habitats. Data from 31 lactating females, satellite tracked over 107 consecutive foraging trips indicated that females foraging on the continental shelf recorded a significantly greater overlap in foraging area between consecutive foraging routes, when compared to females that foraged in oceanic waters (55.9 ± 20.4 % and 13.4 ± 7.6 %, respectively). Findings suggest that seals learn the direction of travel to a predictable foraging region, and initiate a foraging trip on that bearing. However, actual foraging routes are likely to be influenced by a number of factors including previous foraging trip experience and prey encounter rate, which is related to prey density and the spatial scale of the patch exploited. The final chapter integrates scat analysis with milk fatty acid (FA) analysis to investigate dietary differences between continental shelf and oceanic waters. Milk FA composition was determined for 29 satellite-tracked fur seals, that were known to forage in either shelf or oceanic habitats. Based on FA compositions, I predicted the likelihood that milk samples collected at random (n = 131) represented individual seals having foraged either on the continental shelf or in distant oceanic waters. FA analysis and satellite tracking results contrasted with scat analyses, from which only 6 % of scats by frequency of occurrence contained prey remains from oceanic waters. The results suggest that scats were biased toward females foraging on the continental shelf. This study highlights the importance of two predictable ocean features utilised by New Zealand fur seals; (1) a nearby and seasonally predictable coastal upwelling system, the Bonney upwelling and; (2) a distant but permanent oceanic front, the Subtropical Front. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1347312 / Thesis (Ph.D.) - University of Adelaide, School of Earth and Environmental Studies, 2008
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Mother-pup recognition behaviour, pup vocal signatures and allosuckling in the New Zealand fur seal, Arctocephalus forsteriDowell, Sacha January 2005 (has links)
A recognition system is required between pinniped mothers and pups. For otariids this is especially important since females frequently leave their pups for foraging and must reunite on return. Pups must deal with these fasting periods during maternal absence and consequently may attempt to obtain allomaternal care from unrelated females. This research on the New Zealand fur seal (Arctocephalus forsteri) at Ohau Point, Kaikoura, New Zealand, quantified mother-pup recognition behaviour during reunions, individuality of pup calls used by mothers to recognise their pup, and the occurrence of allosuckling as a possible recognition error by females and as a strategy employed by pups to gain allomaternal care during their mothers' absence. A combination of behavioural observations, morphometry, VHF radio telemetry, acoustics and DNA genotyping were employed to study these topics. Postpartum interaction behaviours between mothers and pups appeared to facilitate development of an efficient mother-pup recognition system, involving mainly vocal and olfactory cues that were utilised during reunions. Greater selective pressure on pups to reunite resulted in an asymmetry of searching behaviour between females and pups during reunions. The vocalisations of pups were stereotypic, especially those features of the fundamental frequency and frequency of the lowest harmonic, which are likely to facilitate recognition of a pup by their mother. Pups attempted to steal milk from unrelated females more often during maternal absence and appeared to modify the intra-individual variation pattern of a feature of their vocal signatures over this period, which may assist attempts at allosuckling under nutritional stress. Fostering was demonstrated to occur despite costs to filial pups and possible costs to female reproductive success and may be attributed to development of erroneous recognition between females and non filial pups, or kin selection. This study provides a valuable contribution to the knowledge of recognition systems between pinniped mothers and pups, of alternative pup strategies under nutritional stress and of the rare occurrence of fostering in otariid pinnipeds.
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New Zealand fur seals in the Kaikoura region: colony dynamics, maternal investment and healthBoren, Laura Joy January 2005 (has links)
Colony dynamics, maternal investment, and indicators of health were investigated for the New Zealand fur seal (Arctocephalus forsteri) over four austral summers, 2001- 2005. Effort was focused at the Ohau Point seal colony, north of Kaikoura. Two colonies at Banks Peninsula were included for comparisons of colony growth and pup condition. A range of other colonies were also included for making comparisons about colony dynamics and health indices. Colony dynamics were investigated through mark-recapture estimates of pup production and daily census of all individuals at the Ohau Point colony. Maternal attendance patterns were observed through behavioural observations of known females (n = 120), the use of VHF radio transmitters (n = 33), and female mass and body condition estimates (n = 51). Maternal investment was also investigated through longitudinal sampling of pup mass and growth rates. Parameters used to indicate colony health were: body condition, growth, presence of parasites, and the levels and common causes of mortality. The influence of parasites on pup growth was tested using treatment of selected pups with Ivermectin anti-helmentic medication, and mortality in the region was investigated through reports of dead individuals, and post mortems of those found fresh. The Ohau Point colony is in an exponential state of growth, and pup mass and condition was higher and responded to changes in environmental variables differently than at the Banks Peninsula colonies. Lactation lengths were consistently longer at Ohau Point than is typically reported for the species (323-355 days vs. 285 days). Maternal investment strategies were indicative of a close, reliable food source, and showed flexibility between years through extension of foraging trip durations and the increased use of overnight foraging trips. Individual strategies did not significantly influence pup growth. However, increased maternal condition and the ability to respond to inter-annual changes in resource availability resulted in accelerated pup growth even during an El Niño event. The incidence of pups with intestinal parasites was low at Ohau Point, and the average mass of treated and non-treated pups did not differ. Pup mortality in the region was low (3% to 50 days old), however, mortality of older pups was greatly influenced by the proximity of humans, with 2/3 of pup mortality observed between the age of 50 days and weaning being caused by car collisions. The results suggest that population dynamics and maternal investment in the region are greatly influenced by local variables, notably the presence of an accessible food source within close proximity to the colony. Various indicators of health reflect a growing colony in good condition, and the presence of a reliable food source may influence the maximum density and carrying capacity the colony is able to sustain. However, some concerns are raised about the influence of human interactions in the region, and how this may affect mortality and colony dynamics in the future. Extra fencing along the Ohau Point colony is recommended to provide added protection from the road. Continued monitoring of mortality and health indices in the region is also recommended for comparison with other colonies as Ohau Point reaches carrying capacity and density-dependent pressures increase.
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Mother-pup recognition behaviour, pup vocal signatures and allosuckling in the New Zealand fur seal, Arctocephalus forsteriDowell, Sacha January 2005 (has links)
A recognition system is required between pinniped mothers and pups. For otariids this is especially important since females frequently leave their pups for foraging and must reunite on return. Pups must deal with these fasting periods during maternal absence and consequently may attempt to obtain allomaternal care from unrelated females. This research on the New Zealand fur seal (Arctocephalus forsteri) at Ohau Point, Kaikoura, New Zealand, quantified mother-pup recognition behaviour during reunions, individuality of pup calls used by mothers to recognise their pup, and the occurrence of allosuckling as a possible recognition error by females and as a strategy employed by pups to gain allomaternal care during their mothers' absence. A combination of behavioural observations, morphometry, VHF radio telemetry, acoustics and DNA genotyping were employed to study these topics. Postpartum interaction behaviours between mothers and pups appeared to facilitate development of an efficient mother-pup recognition system, involving mainly vocal and olfactory cues that were utilised during reunions. Greater selective pressure on pups to reunite resulted in an asymmetry of searching behaviour between females and pups during reunions. The vocalisations of pups were stereotypic, especially those features of the fundamental frequency and frequency of the lowest harmonic, which are likely to facilitate recognition of a pup by their mother. Pups attempted to steal milk from unrelated females more often during maternal absence and appeared to modify the intra-individual variation pattern of a feature of their vocal signatures over this period, which may assist attempts at allosuckling under nutritional stress. Fostering was demonstrated to occur despite costs to filial pups and possible costs to female reproductive success and may be attributed to development of erroneous recognition between females and non filial pups, or kin selection. This study provides a valuable contribution to the knowledge of recognition systems between pinniped mothers and pups, of alternative pup strategies under nutritional stress and of the rare occurrence of fostering in otariid pinnipeds.
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New Zealand fur seals in the Kaikoura region: colony dynamics, maternal investment and healthBoren, Laura Joy January 2005 (has links)
Colony dynamics, maternal investment, and indicators of health were investigated for the New Zealand fur seal (Arctocephalus forsteri) over four austral summers, 2001- 2005. Effort was focused at the Ohau Point seal colony, north of Kaikoura. Two colonies at Banks Peninsula were included for comparisons of colony growth and pup condition. A range of other colonies were also included for making comparisons about colony dynamics and health indices. Colony dynamics were investigated through mark-recapture estimates of pup production and daily census of all individuals at the Ohau Point colony. Maternal attendance patterns were observed through behavioural observations of known females (n = 120), the use of VHF radio transmitters (n = 33), and female mass and body condition estimates (n = 51). Maternal investment was also investigated through longitudinal sampling of pup mass and growth rates. Parameters used to indicate colony health were: body condition, growth, presence of parasites, and the levels and common causes of mortality. The influence of parasites on pup growth was tested using treatment of selected pups with Ivermectin anti-helmentic medication, and mortality in the region was investigated through reports of dead individuals, and post mortems of those found fresh. The Ohau Point colony is in an exponential state of growth, and pup mass and condition was higher and responded to changes in environmental variables differently than at the Banks Peninsula colonies. Lactation lengths were consistently longer at Ohau Point than is typically reported for the species (323-355 days vs. 285 days). Maternal investment strategies were indicative of a close, reliable food source, and showed flexibility between years through extension of foraging trip durations and the increased use of overnight foraging trips. Individual strategies did not significantly influence pup growth. However, increased maternal condition and the ability to respond to inter-annual changes in resource availability resulted in accelerated pup growth even during an El Niño event. The incidence of pups with intestinal parasites was low at Ohau Point, and the average mass of treated and non-treated pups did not differ. Pup mortality in the region was low (3% to 50 days old), however, mortality of older pups was greatly influenced by the proximity of humans, with 2/3 of pup mortality observed between the age of 50 days and weaning being caused by car collisions. The results suggest that population dynamics and maternal investment in the region are greatly influenced by local variables, notably the presence of an accessible food source within close proximity to the colony. Various indicators of health reflect a growing colony in good condition, and the presence of a reliable food source may influence the maximum density and carrying capacity the colony is able to sustain. However, some concerns are raised about the influence of human interactions in the region, and how this may affect mortality and colony dynamics in the future. Extra fencing along the Ohau Point colony is recommended to provide added protection from the road. Continued monitoring of mortality and health indices in the region is also recommended for comparison with other colonies as Ohau Point reaches carrying capacity and density-dependent pressures increase.
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Population demographics of New Zealand fur seals (Arctocephalus forsteri)McKenzie, Jane, janemckenzie@malpage.com January 2006 (has links)
Assessment of trophic interactions between increasing populations of New Zealand fur seals (Arctocephalus forsteri) and fisheries in southern Australia is limited due to a lack of species specific demographic data and an understanding of the factors influencing population growth. To establish species specific demographic parameters a cross-sectional sample of New Zealand fur seal females (330) and males (100) were caught and individually-marked on Kangaroo Island, South Australia between 2000 and 2003. The seals were aged through examination of a postcanine tooth, which was removed from each animal to investigate age-specific life-history parameters. Annual formation of cementum layers was confirmed and accuracy in age estimation was determined by examination of teeth removed from individuals of known-age. Indirect methods of assessing reproductive maturity based on mammary teat characteristics indicated that females first gave birth between 4-8 years of age, with an average age at reproductive maturity of 5 years. Among reproductively mature females, age-specific reproductive rates increased rapidly between 4-7 years of age, reaching maximum rates of 70-81% between 8-13 years, and gradually decreased in older females. No females older than 22 years were recorded to pup. Age of first territory tenure in males ranged from 8-10 years. The oldest female and male were 25 and 19 years old, respectively. Post-weaning growth in females was monophasic, characterised by high growth rates in length and mass during the juvenile growth stage, followed by a gradual decline in growth rates after reproductive maturity. In contrast, growth in males was biphasic and displayed a secondary growth spurt in both length and mass, which coincided with sexual and social maturation, followed by a rapid decline in growth rates. Age-specific survival rates were high (0.823-0.953) among prime-age females (8-13 yrs of age) and declined in older females. Relative change in annual pup production was strongly correlated with reproductive rates of prime-age females and adult female survival between breeding seasons.
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