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Providing evidence to improve practice

Individual study: Breeding success of African penguins Spheniscus demersus cleaned and released after the Treasure oil spill at Robben Island, Western Cape, South Africa

Published source details

Barham P.J., Underhill L.G., Crawford R.J.M. & Leshoro T.M. (2007) Differences in breeding success between African penguins (Spheniscus demersus) that were and were not oiled in the MV Treasure oil-spill in 2000. Emu, 107, 7-13


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Clean birds following oil spills Bird Conservation

A controlled, replicated study on Robben Island, South Africa, between 2001 and 2005 (Barham et al. 2007), found that African penguin Spheniscus demersus pairs with at least one parent that had been oiled and rehabilitated (i.e. cleaned and returned to the wild) following an oil spill in 2000 had significantly lower fledging success, compared either to pairs without rehabilitated birds (control pairs), or those with birds banded either for research or following rehabilitation from earlier oil spills (43% of 321 chicks fledging from pairs with rehabilitated birds vs. 61% of 170 from controls and  61% of 114 from previously-banded pairs). Hatching success and clutch size were not significantly different between groups and the differences in fledging success were due to high levels of mortality in older chicks from rehabilitated pairs.