The Best Nest
In the Western Cape of South Africa, there are a handful of African penguins, Spfeniscus demersus. In South Africa there is a colony of African penguins that live at Boulders Beach, just a few steps away from the residents of Simon’s Town. To help preserve the beach for penguin use, South African National Parks has administered and manages it along with Table Mountain National Park. Here the penguins have access to safe beaches, and man made nesting sites if need be. The man made nesting sites were located throughout the upper portion of the park, under bushes and shrubs and many were away from tourist’s eyes. Pictured above are an adult and juvenile. Prior to this photo, the juvenile was resting in the nest behind with the other juvenile. While this photo was being shot, the adult was pushing and pecking the juvenile away from the nest behind. It appeared as if the juvenile above wondered into a neighboring nest, while the adult was away. Now with many of the fledglings too large to remain in the artificial homes above, I pondered the question “was this juvenile confused on which nest was his because he grew up in an artificial nest, and now must reside in this new nest because he outgrew the last one?” I know that this question can not be answered since there hasn’t been enough observation to really know the whole picture behind this particular animals behavior, but I did leave the park wanting to know exactly how the artificial nest structures impact the survival rates of fledglings. There have been a few studies conducted on the breeding productivity of African penguins. One study, conducted by Sherley et al, observed if artificial nests enhanced breeding productivity on Robben Island South Africa. In that study, they replaced lost habitat with two different artificial structures and observed reproductive output from 2001–2010. In this study, they found that at the beginning of the study, there were roughly 6700 breeding pairs, which then spike to 8500 in 2004 but then saw a decline to about 2500 pairs in 2010. The two types of artificial housing structures were either a plywood structure or a fiberglass artificial burrow. The types of artificial burrows in Simon’s Town were designed just like the fiberglass artificial burrows. In another study conducted by Lorien Pichegru, looked at the success rate due to artificial nests and the culling of predatory gulls from Bird Island, South Africa. In the study by Pichegru, it was documented that artificial nests improved the survival for chicks on Bird Island. It was also noted that depending on the design of the artificial nest also determined the survival rate of the chick. The fiberglass burrows had consistently poor conditions compared to natural burrows. The fiberglass versions created temperatures too high to allow most eggs to hatch. After reading these articles the artificial nests may have some small flaws, but research is still being done to see which type of housing works best. Artificial nests help protect penguins from severe weather events and can help save eggs from predatory gulls, unlike natural surface nests. To help protect these beautiful birds, we must continue to study the effects of artificial nests, limit fishing to ensure enough food during breeding seasons, and limit human interactions to avoid potential nest abandonment.
Work Cited
Pichegru, L. (2013). Increasing breeding success of an Endangered penguin: artificial nests or culling predatory gulls?. Bird Conservation International, 23(3), 296–308.
Sherley, R. B., Barham, B. J., Barham, P. J., Leshoro, T. M., & Underhill, L. G. (2012). Artificial nests enhance the breeding productivity of African Penguins (Spheniscus demersus) on Robben Island, South Africa. Emu-Austral Ornithology, 112(2), 97–106.
