Breeding success of African penguins Spheniscus demersus at Dassen Island, especially after oiling following the Apollo Sea spill
| dc.contributor.author | Wolfaardt, A C | |
| dc.contributor.author | Underhill, L G | |
| dc.contributor.author | Nel, D C | |
| dc.contributor.author | Williams, A J | |
| dc.contributor.author | Visagie, J | |
| dc.date.accessioned | 2016-11-14T08:59:57Z | |
| dc.date.available | 2016-11-14T08:59:57Z | |
| dc.date.issued | 2008 | |
| dc.date.updated | 2016-01-22T10:01:09Z | |
| dc.description.abstract | The reproductive success of African penguins Spheniscus demersus at Dassen Island from 1994 to 2000 was variable, but much higher than previously reported figures for the species. Breeding success was positively related to the abundance of anchovy Engraulis encrasicolus and sardine Sardinops sagax, and the high reproductive output during the study was attributed to the large biomass and high availability of these two species for much of the study period. De-oiled penguins from the Apollo Sea spill had a slightly lower hatching success but a significantly lower overall breeding success than that of un-oiled birds, driven mainly by the reduced number of chicks which fledged. Nests with two de-oiled Apollo Sea parents were less successful than nests with one de-oiled bird. There was increased mortality of chicks 40 days and older in nests with de-oiled birds. Chicks from nests with one de-oiled Apollo Sea parent grew at a similar rate to chicks from nests with no de-oiled parents. However, chicks from nests that comprised two de-oiled Apollo Sea birds had significantly slower growth rates than these other two groups. Breeding success and chick growth at nests with de-oiled birds were more negatively impacted when feeding conditions were less favourable. These results suggest that one of the main reasons for lower breeding success in de-oiled birds was their reduced ability to provision chicks, especially during the period in which the energy demands of the chicks is greatest. The rate of mate fidelity was lower in de-oiled birds than un-oiled birds, and there was a positive association between mate fidelity and breeding success. | |
| dc.identifier | http://dx.doi.org/10.2989/AJMS.2008.30.3.10.644 | |
| dc.identifier.apacitation | Wolfaardt, A. C., Underhill, L. G., Nel, D. C., Williams, A. J., & Visagie, J. (2008). Breeding success of African penguins Spheniscus demersus at Dassen Island, especially after oiling following the Apollo Sea spill. <i>African Journal of Marine Science</i>, http://hdl.handle.net/11427/22525 | en_ZA |
| dc.identifier.chicagocitation | Wolfaardt, A C, L G Underhill, D C Nel, A J Williams, and J Visagie "Breeding success of African penguins Spheniscus demersus at Dassen Island, especially after oiling following the Apollo Sea spill." <i>African Journal of Marine Science</i> (2008) http://hdl.handle.net/11427/22525 | en_ZA |
| dc.identifier.citation | Wolfaardt, A. C., Underhill, L. G., Nel, D. C., Williams, A. J., & Visagie, J. (2008). Breeding success of African penguins Spheniscus demersus at Dassen Island, especially after oiling following the Apollo Sea spill. African Journal of Marine Science, 30(3), 565-580. | |
| dc.identifier.ris | TY - Journal Article AU - Wolfaardt, A C AU - Underhill, L G AU - Nel, D C AU - Williams, A J AU - Visagie, J AB - The reproductive success of African penguins Spheniscus demersus at Dassen Island from 1994 to 2000 was variable, but much higher than previously reported figures for the species. Breeding success was positively related to the abundance of anchovy Engraulis encrasicolus and sardine Sardinops sagax, and the high reproductive output during the study was attributed to the large biomass and high availability of these two species for much of the study period. De-oiled penguins from the Apollo Sea spill had a slightly lower hatching success but a significantly lower overall breeding success than that of un-oiled birds, driven mainly by the reduced number of chicks which fledged. Nests with two de-oiled Apollo Sea parents were less successful than nests with one de-oiled bird. There was increased mortality of chicks 40 days and older in nests with de-oiled birds. Chicks from nests with one de-oiled Apollo Sea parent grew at a similar rate to chicks from nests with no de-oiled parents. However, chicks from nests that comprised two de-oiled Apollo Sea birds had significantly slower growth rates than these other two groups. Breeding success and chick growth at nests with de-oiled birds were more negatively impacted when feeding conditions were less favourable. These results suggest that one of the main reasons for lower breeding success in de-oiled birds was their reduced ability to provision chicks, especially during the period in which the energy demands of the chicks is greatest. The rate of mate fidelity was lower in de-oiled birds than un-oiled birds, and there was a positive association between mate fidelity and breeding success. DA - 2008 DB - OpenUCT DP - University of Cape Town J1 - African Journal of Marine Science KW - African penguin KW - Apollo Sea KW - breeding success KW - chick growth KW - Dassen Island KW - de-oiled KW - mate fidelity KW - Spheniscus demersus LK - https://open.uct.ac.za PB - University of Cape Town PY - 2008 T1 - Breeding success of African penguins Spheniscus demersus at Dassen Island, especially after oiling following the Apollo Sea spill TI - Breeding success of African penguins Spheniscus demersus at Dassen Island, especially after oiling following the Apollo Sea spill UR - http://hdl.handle.net/11427/22525 ER - | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/11427/22525 | |
| dc.identifier.uri | http://www.tandfonline.com/doi/abs/10.2989/AJMS.2008.30.3.10.644 | |
| dc.identifier.vancouvercitation | Wolfaardt AC, Underhill LG, Nel DC, Williams AJ, Visagie J. Breeding success of African penguins Spheniscus demersus at Dassen Island, especially after oiling following the Apollo Sea spill. African Journal of Marine Science. 2008; http://hdl.handle.net/11427/22525. | en_ZA |
| dc.language.iso | eng | |
| dc.publisher.department | Department of Biological Sciences | en_ZA |
| dc.publisher.faculty | Faculty of Science | en_ZA |
| dc.publisher.institution | University of Cape Town | |
| dc.source | African Journal of Marine Science | |
| dc.source.uri | http://www.tandfonline.com/doi/abs/10.2989/AJMS.2008.30.3.10.644 | |
| dc.subject | African penguin | |
| dc.subject | Apollo Sea | |
| dc.subject | breeding success | |
| dc.subject | chick growth | |
| dc.subject | Dassen Island | |
| dc.subject | de-oiled | |
| dc.subject | mate fidelity | |
| dc.subject | Spheniscus demersus | |
| dc.title | Breeding success of African penguins Spheniscus demersus at Dassen Island, especially after oiling following the Apollo Sea spill | |
| dc.type | Journal Article | |
| uct.type.filetype | Text | |
| uct.type.filetype | Image | |
| uct.type.publication | Research |