A new study by an international team of researchers from South Africa and the UK has unveiled that artificial nests can boost the breeding success of endangered African penguins, but there’s no one-size-fits-all design.
Led by researchers at Nelson Mandela University, the study, spanning 12 years and multiple locations in South Africa, demonstrated that artificial nests outperformed natural ones, resulting in a remarkable 16.5% increase in breeding output.
The study also highlighted that no single style of artificial nest reigned supreme across all penguin colonies. Each design exhibited distinct strengths and weaknesses. Notably, the newly developed double-layered ceramic nests emerged as a standout, showcasing superior performance compared to earlier designs, although their effectiveness was not uniform across all locations.
“The most effective designs of artificial nests were colony-specific, with different colonies facing different threats,” said Professor Lorien Pichegru, lead researcher at the Institute for Coastal and Marine Research, Nelson Mandela University. “Penguins at land colonies such as Boulders Beach face threats from mammals, whereas penguins at colonies devoid of vegetation such as Bird Island face sun exposure. Different artificial nest designs were more suited to responding to different threats.”
The results underscore the effectiveness of artificial nests as a conservation measure for African penguins. However, given the lack of a universal design, tailored conservation strategies for each colony are imperative.
The persistent decline in African penguin populations necessitates more comprehensive conservation efforts, particularly by enhancing food availability.
“The main causes of the recent decline in African penguin numbers are poor food availability, oil spills, underwater noise pollution, and predation.” Explained Professor Pichegru. “Biologically meaningful fishing exclusion zones around their major colonies are urgently needed.”
African penguins are teetering on the brink of extinction, with their populations plummeting by a staggering 90% over the past 70 years. To address the critical shortage of nesting habitat for these vulnerable seabirds, artificial nests have been deployed at various colonies in South Africa for over three decades.
In a compelling study, researchers investigated the breeding success of African penguins over a 12-year period at the eight largest colonies in South Africa, meticulously comparing natural nests with four types of artificial nests. The researchers vigilantly monitored the nests on a weekly basis from the time eggs were laid until chick fledgling or nest failure, aiming to shed light on the effectiveness of these interventions.
The cutting-edge artificial nests featured a range of innovative designs, from newly crafted ceramic nests with slanted roofs and 5cm airgaps to A-framed pine plywood nests, cement nests made of a fiberglass and cement blend, and fiberglass burrows that closely mimic the natural penguin burrow shape.
However, the researchers caution that the study may have slightly underestimated breeding success in natural nests due to the challenges of monitoring them. Natural nests are often selected in inaccessible areas to minimize disturbance, potentially leaving them more vulnerable to the elements and predators.
“We also weren’t always able to follow the fate of individual birds or breeding pairs closely over multiple years in this study,” said Dr Richard Sherley, a co-author from the University of Exeter.
“That means we can’t be certain how much of the benefit we measured comes from the ‘best’ penguins actively choosing to breed in artificial nests. So, it would also help conservation strategy if we could understand what makes an artificial nest attractive to penguins or not!” he added.
Professor Pichegru agreed that future research in this area could make artificial nest designs even more effective. “Understanding the mechanisms by which artificial nests improve breeding success at different colonies could help to improve future artificial nest designs. For instance, is it improved protection from predators, is it decrease heat loads on eggs or something else?”
Journal reference:
- L. Pichegru, R. B. Sherley, T. Malan, B. J. Barham, K. Ludynia, D. Geldenhuys, K. Amos, P. J. Barham, E. Drost, V. Hahndiek, A. Hufke, C. Hugo, C. Lawrence, C. McGeorge, A. M. McInnes, A. M. Makhado, M. Mashau, R. Milne, A. Purves, M. Slier, C. van der Merwe, N. J. van Wilgen, L. Waller. Decades of artificial nests towards African penguin conservation—Have they made a difference? Ecological Solutions and Evidence, 2024; DOI: 10.1002/2688-8319.12388
