By Stephen Beech via SWNS
Artificial nests boost the breeding success of endangered penguins, reveals new research.
But there’s no “one-size-fits-all” design that proves ultimately successful, say scientists.
Different designs were more effective among different colonies of African penguins, according to the findings of a team of researchers from the UK and South Africa.
The study involved monitoring the breeding success of African penguins for 12 years at sites across South Africa.
The findings showed that artificial nests outperformed natural nests and increased breeding output by 16.5%.
The researchers also discovered that no single style of artificial nest was the most effective across penguin colonies, with each type having strengths and weaknesses.
New double-layered ceramic nests were generally the most effective type of nest compared to earlier designs, but that was not universal.
Lead researcher Professor Lorien Pichegru, of Nelson Mandela University in South Africa, said: “The most effective designs of artificial nests were colony-specific, with different colonies facing different threats.
“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, published in the British Ecological Society journal Ecological Solutions and Evidence, show that artificial nests can be an “effective” conservation measure for African penguins.
But because there isn’t a one-size-fits-all design, colony-specific conservation strategies are required.
Conservationists say that the continuing decline in African penguin numbers means that further action is needed beyond artificial nests, primarily through increasing food availability.
Prof Pichegru said: “The main causes of the recent decline in African penguin numbers are poor food availability, oil spills, underwater noise pollution and predation.
“Biologically meaningful fishing exclusion zones around their major colonies are urgently needed.”
She explained that African penguins are one of the most threatened seabird species globally and face an “extremely high” chance of becoming extinct.
Populations have declined by 90% in the last 70 years to around just 8,500 breeding pairs.
To combat a lack of nesting habitat for the burrowing seabirds, which leaves them vulnerable to predators and extreme weather, artificial nests have been deployed at various colonies along the coast of South Africa for over 30 years.
In the new study, researchers looked at the breeding success of African penguins over a 12-year period at the eight largest penguin colonies in South Africa.
The team checked both natural nests and four types of artificial nests weekly from when eggs were laid until chick fledgling or nest failure.
The artificial nests included the newly designed ceramic nests which have slanted roofs and 5cm airgap between layers, A-framed pine plywood nests – the oldest design, cement nests made of a mixture of fiberglass and cement, and fiberglass burrows which mimic the shape of natural penguin burrows.
The researchers say that breeding success in natural nests may have been slightly underestimated in the study due to the logistical challenges of monitoring them.
Natural nests monitored for breeding success are often chosen in accessible areas to reduce disturbance and so can be more exposed to weather and predators.
Study co-author Dr. Richard Sherley, from the University of Exeter, said: “We also weren’t always able to follow the fate of individual birds or breeding pairs closely over multiple years in this study.
“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.”
Prof Pichegru says that future research in this area could make artificial nest designs even more effective.
She added: “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?”
