From incubation to release: Hand-rearing as a tool for the conservation of the endangered African penguin.

The African penguin (Spheniscus demersus) population is estimated at 25,000 breeding pairs, approximately 5% of that at the start of the 20th century, and the species is currently classified as Endangered. In the last two decades, the hand-rearing of penguin chicks that were abandoned by their parents due to oil spills or other circumstances has become a valuable conservation tool to limit mortality and to bolster the population at specific colonies. We summarize and evaluate the techniques employed by the Southern African Foundation for the Conservation of Coastal Birds (SANCCOB) to incubate and hand-rear African penguin eggs and chicks. From 2012 to 2016, a total of 694 eggs and 2819 chicks were received by SANCCOB's Chick Rearing Unit. It was estimated that 13% of the eggs were infertile, and 81% of the fertile eggs hatched successfully. The overall release rate for chicks was 77%, with a higher release rate for chicks that were pre-emptively removed (93%) followed by chicks that had been abandoned by their parents (78%), chicks admitted due to avian pox lesions (61%), chicks that hatched from artificially-incubated eggs (57%), and chicks admitted due to injuries or deformities (25%). Rescuing and hand-rearing eggs and chicks has been a successful strategy for African penguins, and might be also applicable for the conservation of other threatened seabird species whose population are critically low or during natural or anthropogenic events that could have disastrous population impacts (e.g. oil spills, disease outbreaks, catastrophic weather events, strong El Niño years, etc.).