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Survival of the southern elephant seal, mirounga leonina, population of Marion Island
Dissertation (MSc (Zoology))--University of Pretoria, 1999.
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| Format: | Thesis |
| Language: | English |
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University of Pretoria
2022
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| _version_ | 1867613569438187520 |
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| access_status_str | Open Access |
| author2 | Bester, Marthan Nieuwoudt |
| author_browse | Bester, Marthan Nieuwoudt |
| author_facet | Bester, Marthan Nieuwoudt |
| collection | Thesis |
| dc_rights_str_mv | © 2021 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 (Zoology))--University of Pretoria, 1999. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/83284 |
| institution | University of Pretoria (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:38:13.749Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2022 |
| publishDateRange | 2022 |
| publishDateSort | 2022 |
| 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:2263/83284 Survival of the southern elephant seal, mirounga leonina, population of Marion Island Bester, Marthan Nieuwoudt Pistorius, Pierre Anton UCTD Survival southern elephant seal mirounga leonina population Marion Island Dissertation (MSc (Zoology))--University of Pretoria, 1999. Demographic parameters from a 14-year mark-recapture program on southern elephant seals at Marion Island were investigated. Using the computer package MARK, first year survival was estimated at 0.58 and 0.62, and equated over the first three years of life, 0.69 and 0.74 for males and females respectively. From years four to nine the average survival rate was 0.66 and 0. 75 for males and females respectively. Considerable reductions in fourth- and fifth-year male survival, and fourth year female survival were observed over the study. period. Poor adult survival is implied as the proximate cause, and food limitation as deduced from the _decline in survival of seals with high energetic demands, as the ultimate cause behind the population decline. Fecundity was 0.25 for three-year-olds, 0.42 for four-year-olds, and 0.44 for five-year-olds, with a significant increase in these rates being evident over the course of the study. A conversion factor of3.15 was estimated and applied to annual pup production in order to assess population size. The present population size was estimated at 1263 individuals, and the population declined exponentially at an annual rate of 4.3% from 1986 to 1997, which slowed to 2.5% per annum over the last six years. Zoology and Entomology MSc (Zoology) Unrestricted 2022-01-12T06:01:17Z 2022-01-12T06:01:17Z 19/8/2021 1999 Dissertation * http://hdl.handle.net/2263/83284 en © 2021 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 Survival southern elephant seal mirounga leonina population Marion Island Survival of the southern elephant seal, mirounga leonina, population of Marion Island |
| title | Survival of the southern elephant seal, mirounga leonina, population of Marion Island |
| title_full | Survival of the southern elephant seal, mirounga leonina, population of Marion Island |
| title_fullStr | Survival of the southern elephant seal, mirounga leonina, population of Marion Island |
| title_full_unstemmed | Survival of the southern elephant seal, mirounga leonina, population of Marion Island |
| title_short | Survival of the southern elephant seal, mirounga leonina, population of Marion Island |
| title_sort | survival of the southern elephant seal mirounga leonina population of marion island |
| topic | UCTD Survival southern elephant seal mirounga leonina population Marion Island |
| url | http://hdl.handle.net/2263/83284 |