New Zealand fur seals in the Kaikoura region: colony dynamics, maternal investment and health Laura J. Boren A thesis submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Biological Sciences, At the University of Canterbury University of Canterbury 2005 2 Declaration of Originality This thesis contains no material which has been accepted for a degree or diploma by the University or any other institution, and to the best of my knowledge and belief, contains no material previously published or written by another person, except when due acknowledgement is made in the text of the thesis. Laura J. Boren 3 Declaration by candidate I certify that this thesis represents an original and independent piece of research. All of the significant aspects of analysis and interpretation of the results were done by myself. This thesis is being presented as a series of papers to be submitted. The nature of the collaborations indicated by the co-authorship of these papers takes three forms: 1. Supervisors: (Gemmell, Caudron and Chilvers). As senior author I wish to recognise the contributions of my advisors in my training by including them as co-authors. 2. Many of the field components involved a large time commitment contributed by others over a series of 3+ years, as well as a contribution of supporting data (some pup birth dates - Dowell) and a significant amount of technical contributions (Muller). For these reasons I have chosen to recognise the collaboration of Caudron, Muller and Dowell as co-authors. 3. Finally, historical data collection from Kaikoura, (Morrissey), colony comparison information from Open Bay Islands (Stratton), and training in histological analysis (Stratton and Duignan) are also recognised. Further manuscripts that have not been included in this thesis but that have originated from collaboration at this field site include but are not limited to: • Caudron A.K., Negro S.S, Muller C.G, Boren L.J. & Gemmell N.J. (Submitted) Hair sampling and genotyping from follicles : A minimally-invasive alternative for genetics studies in small, mobile pinnipeds. (Submitted to Marine Mammal Science). • Boren, L.J. and Caudron, A.K. The reliability of different methods for short- and long-term identification of fur seals : adult males, females and pups. • Boren, L.J., Muller, C.G., and Dowell, S. A comparison of techniques: the effectiveness of behavioural and telemetry data to determine the foraging behaviour of adult female fur seals at a large boulder colony. • Boren, L.J., Connolly, J. and Gemmell, N.J. The potential for Salmonella in fur seals on the East Coast. • Immunological health of pups at Ohau Point • Caudron A., Negro S., Fowler M., Boren L., Poncin P. & Gemmell N. Diversification of male breeding strategies and their success in a polygynous mammal, the NZ fur seal Arctocephalus forsteri. 4 • Caudron A., Cockrem J., Boren L., Sulon J., Poncin P. & Gemmell N. How stressed are our study pups? A preliminary study in wild fur seals using free cortisol in pup saliva. • Caudron A., Boren L. & Gemmell N. Differences between cortisol and corticosterone concentrations in the faeces of adult versus pup fur seals. • Caudron A., Boren L. Cockrem J., & Gemmell, N. The potential for use of coritsol and corticosterone concetrations in the feaces of New Zealand fur seals to detect the effect of tourist disturbance on stress levels. Laura J. Boren 5 Table of Contents Declaration of Originality .......................................................................................2 Declaration by candidate.........................................................................................3 Table of Contents .....................................................................................................5 List of Figures.........................................................................................................10 List of Tables ..........................................................................................................14 Abstract...................................................................................................................18 Chapter 1: Introduction .........................................................................21 Pinnipeds.................................................................................................................21 New Zealand fur seals............................................................................................22 Distribution ..........................................................................................................22 Natural history and colony dynamics ..................................................................25 Maternal investment.............................................................................................25 Colony status and health ......................................................................................27 Reproductive and morphological parameters ..................................................27 Mortality and disease .......................................................................................29 New Zealand fur seals and the Kaikoura region.................................................31 Kaikoura history...................................................................................................31 Kaikoura’s appeal to marine mammals................................................................32 Re-colonisation of fur seals in Kaikoura .............................................................35 Breeding biology of A. forsteri in Kaikoura ........................................................36 Global and local concerns for marine mammals including A. forsteri..............36 Tourism................................................................................................................36 Fisheries interactions ...........................................................................................37 Re-colonisation effects on global and local marine industries ............................38 Thesis Aims.............................................................................................................39 References:..............................................................................................................41 Chapter 2: Colony growth and pup condition on the Kaikoura coastline; a comparison with other East Coast colonies .....................51 Abstract...................................................................................................................51 Introduction............................................................................................................52 History of harvesting............................................................................................52 Re-colonisation history ........................................................................................52 Condition of pups.................................................................................................54 Re-colonisation in Kaikoura ................................................................................54 Methods...................................................................................................................56 Study sites ............................................................................................................56 Sample sizes and dates.........................................................................................58 Pup production estimates .....................................................................................58 Gender, Morphology, and Condition...................................................................59 Results .....................................................................................................................60 Colony growth and estimates of pup production .................................................60 Kaikoura Coastline...........................................................................................60 Banks Peninsula...............................................................................................60 General colony growth.....................................................................................60 Sex ratios..............................................................................................................61 Morphological Characteristics.............................................................................62 Mass .................................................................................................................62 6 Dorsal Straight Length.....................................................................................62 Condition Index 1: M/DSL ..............................................................................63 Condition Index 2: Observed / Expected Mass................................................63 Discussion................................................................................................................67 Colony growth and estimates of pup production .................................................67 Morphological Characteristics.............................................................................68 Conclusions.............................................................................................................70 References:..............................................................................................................71