A new study by an international team of researchers from South Africa and the United Kingdom has revealed that artificial nests can significantly improve the breeding success of endangered African penguins (Spheniscus demersus). The research, published in the British Ecological Society’s journal Ecological Solutions and Evidence, highlights the potential role of artificial nests in conserving this critically endangered species.
Population Decline of African Penguins
African penguins, endemic to Southern Africa, are critically endangered. Despite a brief recovery in the 1990s and early 2000s, their population has plummeted by 90% over the past 70 years. In 1956, there were approximately 93,000 breeding pairs, but by 2023, this number had dwindled to around 9,900 pairs. The study identifies food scarcity and human disturbances as the primary reasons for this drastic decline.
Use of Artificial Nests to Improve Breeding Success
To combat these threats, conservationists have introduced artificial nests across penguin colonies in South Africa and Namibia over the past three decades. The goal is to create safer and more suitable breeding habitats. African penguins typically breed in burrows dug into guano, a natural substance composed of bird, bat, and seal excrement, which protects their eggs and chicks from extreme heat, harsh winds, and rain.
However, penguins have shown a preference for artificial nests over natural burrows. The 12-year study found that breeding success was 16.5% higher in artificial nests compared to natural ones.
Study Design and Key Findings
The research, conducted in eight of the largest African penguin colonies in South Africa, monitored four different types of artificial nests alongside natural ones. These nests were assessed based on their ability to protect eggs and chicks from threats such as predators and environmental extremes. The study tracked the progress of eggs from laying to the successful fledging of chicks.
Different Artificial Nest Designs
The study tested various nest designs, including:
- Ceramic nests: These had slanted roofs and a 5 cm air gap between layers for heat regulation, and they showed the highest overall effectiveness.
- A-frame pine plywood nests: These wooden structures were also tested.
- Cement and fibreglass nests: These were designed to mimic natural burrows.
Interestingly, no single nest design proved superior across all colonies. The effectiveness of each design varied depending on the threats faced by penguins in specific colonies. For instance, colonies at Boulders Beach, which are vulnerable to mammal predators, had different needs compared to colonies like Bird Island, where sun exposure is a primary concern.
Examples of Nest Performance
- Robben Island: Wooden boxes deployed in 2001 increased fledging success compared to nests under vegetation. Fibreglass nests also performed well here.
- Bird Island and Dyer Island: Results for fibreglass nests were mixed compared to vegetation nests.
Challenges and Future Directions
The study noted that breeding success in natural nests might be slightly underestimated due to difficulties in monitoring them, particularly in remote or hard-to-reach areas. Additionally, it remains unclear whether the higher success rates in artificial nests are due to the “best” penguins choosing these nests or the nest designs themselves.
Professor Pichegru, the lead researcher, emphasized the importance of further research to understand why certain artificial nests work better in specific colonies. This knowledge could help improve future nest designs by addressing factors such as predator protection and heat regulation.
Conclusion: The Need for Comprehensive Conservation Efforts
While artificial nests have shown promise in boosting breeding success, the researchers stressed that they alone cannot save the African penguin population. Major threats such as food scarcity, oil spills, and underwater noise pollution remain significant challenges. The authors call for the establishment of biologically meaningful fishing exclusion zones around penguin colonies to ensure their long-term survival.
Multiple-Choice Questions (MCQs):
- What is the primary aim of introducing artificial nests for African penguins?
- a) To attract tourists
- b) To increase breeding success
- c) To monitor penguin movement
- d) To reduce penguin population
Answer: b) To increase breeding success
- By how much has the African penguin population decreased over the past 70 years?
- a) 50%
- b) 60%
- c) 70%
- d) 90%
Answer: d) 90%
- Which type of artificial nest showed the highest overall effectiveness in the study?
- a) A-frame pine plywood nests
- b) Fibreglass burrows
- c) Ceramic nests
- d) Wooden boxes
Answer: c) Ceramic nests
- What are the major threats to African penguins apart from the availability of artificial nests?
- a) Overpopulation and pollution
- b) Food scarcity, oil spills, and underwater noise pollution
- c) Lack of shelter and human interaction
- d) Invasive species and disease
Answer: b) Food scarcity, oil spills, and underwater noise pollution
- What is the next step researchers suggest to improve artificial nest designs for penguins?
- a) Decrease the size of the nests
- b) Understand what makes artificial nests attractive to penguins
- c) Use more natural materials
- d) Relocate penguin colonies
Answer: b) Understand what makes artificial nests attractive to penguins