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Occurrence and group dynamics of Heaviside’s dolphins (Cephalorhynchus heavisidii) in Table Bay, Western Cape, South Africa
Dissertation (MSc)--University of Pretoria, 2011.
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University of Pretoria
2013
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| _version_ | 1867613500468101121 |
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| access_status_str | Open Access |
| author2 | Karczmarski, Leszek |
| author_browse | Karczmarski, Leszek |
| author_facet | Karczmarski, Leszek |
| collection | Thesis |
| dc_rights_str_mv | © 2012, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Dissertation (MSc)--University of Pretoria, 2011. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/30835 |
| institution | University of Pretoria (South Africa) |
| last_indexed | 2026-06-10T12:37:08.286Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2013 |
| publishDateRange | 2013 |
| publishDateSort | 2013 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/30835 Occurrence and group dynamics of Heaviside’s dolphins (Cephalorhynchus heavisidii) in Table Bay, Western Cape, South Africa Karczmarski, Leszek Keith, Mark De Bruyn, P.J. Nico Behrmann, Caryn Ann UCTD Cephalorhynchus heavisidii Heaviside's dolphin (Cephalorhynchus heavisidii) Photo-identification Group Dynamics Dissertation (MSc)--University of Pretoria, 2011. Heaviside‟s dolphins, Cephalorhynchus heavisidii, are among the least known cetaceans. They are endemic to the coastal waters along the west coast of southern Africa. The occurrence, behaviour and group dynamics were investigated for these dolphins in Table Bay, South Africa during the summer of 2008 and 2009. Markrecapture photographic identification techniques, modelling techniques and Geographical Information System (GIS) were used to analyse the data. The dolphins were observed primarily in a well-defined 7 km2 area on the south side of Table Bay along a 3 km east-west stretch of coast known as Granger Bay, and within 2 km from shore. They used this area heterogeneously; for the array of behaviours observed, all core areas (50 % kernels) were located in Granger Bay with very little overlap of areas used for milling, socialising, resting and travelling. Milling and socialising were exhibited more often than travelling and resting. Foraging was never observed in areas close to shore, which supports earlier studies suggesting that these dolphins forage primarily offshore. Of the 95 identified individuals, 24.2 % of the individuals were seen only once and 73.7 % of the individuals were sighted less than five times while two individuals were seen 11 times. Groups varied in size from one to 26 animals with a median of five animals. Many of the potential dyads were never seen and those observed had generally weak measure of association. The group structure appears highly dynamic, with great lability in group sizes and membership, suggesting a fluid social system with mostly weak inter-individual bonds. Individuals in Table Bay display low site fidelity, at least in the short-term. The observed pattern of area use and behavioural preferences indicate that coastal management strategies should consider the ecological and behavioural needs of Heaviside's dolphins to appropriately safeguard this species as a valuable component of South African natural treasures and legally protected taxa. Further continuing research is needed to build on this initial study to better understand the processes that shape the population structure and group dynamics of Heaviside's dolphins, and to provide further detail on habitat preferences and areas used, both in Table Bay and environs. Zoology and Entomology Unrestricted 2013-09-09T07:40:55Z 2012-05-21 2013-09-09T07:40:55Z 2012-04-19 2011 2012-05-21 Dissertation Behrmann, C 2011, Occurrence and group dynamics of Heaviside’s dolphins (Cephalorhynchus heavisidii) in Table Bay, Western Cape, South Africa, MSc dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-05212012-104405/ > C12/4/109/gm http://hdl.handle.net/2263/30835 http://upetd.up.ac.za/thesis/available/etd-05212012-104405/ © 2012, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | UCTD Cephalorhynchus heavisidii Heaviside's dolphin (Cephalorhynchus heavisidii) Photo-identification Group Dynamics Occurrence and group dynamics of Heaviside’s dolphins (Cephalorhynchus heavisidii) in Table Bay, Western Cape, South Africa |
| title | Occurrence and group dynamics of Heaviside’s dolphins (Cephalorhynchus heavisidii) in Table Bay, Western Cape, South Africa |
| title_full | Occurrence and group dynamics of Heaviside’s dolphins (Cephalorhynchus heavisidii) in Table Bay, Western Cape, South Africa |
| title_fullStr | Occurrence and group dynamics of Heaviside’s dolphins (Cephalorhynchus heavisidii) in Table Bay, Western Cape, South Africa |
| title_full_unstemmed | Occurrence and group dynamics of Heaviside’s dolphins (Cephalorhynchus heavisidii) in Table Bay, Western Cape, South Africa |
| title_short | Occurrence and group dynamics of Heaviside’s dolphins (Cephalorhynchus heavisidii) in Table Bay, Western Cape, South Africa |
| title_sort | occurrence and group dynamics of heaviside s dolphins cephalorhynchus heavisidii in table bay western cape south africa |
| topic | UCTD Cephalorhynchus heavisidii Heaviside's dolphin (Cephalorhynchus heavisidii) Photo-identification Group Dynamics |
| url | http://hdl.handle.net/2263/30835 http://upetd.up.ac.za/thesis/available/etd-05212012-104405/ |