The endangered African penguin could be under further threat by tourists, prompting a call from scientists to limit visits to affected colonies.
A University of Pretoria-led (UP) study has revealed that close interaction of tourists with African penguin chicks could cause them stress.
This could result in immunosuppression, leaving them susceptible to disease, while their reproductivity could be reduced, warn the scientists.
The endangered African penguin is found in SA and Namibia, and has become a popular attraction in the Western Cape.
Its population sizes have decreased dramatically over the past four decades and the birds face extinction.
The study was recently published in the journal Conservation Physiology and involved the work of Dr Juan Scheun, a research fellow at UP’s Mammal Research Institute; its director Prof Andre Ganswindt; and scientists from Exeter University in the UK, the University of the Western Cape (UWC) and Nelson Mandela University (NMU).
“The team conducted a study of the stress-related hormone levels of chicks at three sites within two breeding colonies on Robben Island and in Stony Point. Both had varying levels of exposure to tourism,” said Dr Scheun.
The Stony Point African penguin colony is next to a residential area in Betty’s Bay, in the Western Cape.
The site was first colonised by the birds in 1982 and became one of the largest breeding colonies in SA.
The African penguin colony at Robben Island in Table Bay was recolonised in 1983 after a 180-year absence of the species at the study site.
“In total, 320,000 tourists travel to the island annually to visit several historical landmarks,” Dr Scheun said.
“Faecal samples from penguin chicks were collected to analyse stress-related hormone levels to understand the adrenocortical functions of penguins, especially when their environment appeared to be threatened by humans and their activities.”
They found that unpredictable human presence was likely to be responsible for the increase in stress-related hormone levels in chicks.
Other factors, such as food shortages, may also be contributing to these elevated levels.
The presence of overzealous tourists, particularly at the breeding colonies, could be causing stress among the chicks.
“Tourist groups sometimes get too close to the penguins and feed them; they also get close to take photographs,” said Ganswindt.
The management of tourism sites should attempt to minimise all forms of activity around important breeding colonies that are not already exposed to regular tourism.
— Dr Juan Scheun, a research fellow at UP's Mammal Research Institute
Scheun added that African penguin chicks are unable to avoid the strain brought on by the presence of humans.
“Chicks can’t swim yet (like their parents can), nor can they move with speed across the terrestrial landscape to escape a stressor. In a sense, they have to ride it out.”
To protect the wellbeing of these chicks, Scheun and Ganswindt are calling for a limitation on the number of tourists who visit these colonies.
“The management of tourism sites should attempt to minimise all forms of activity around important breeding colonies that are not already exposed to regular tourism.
“There should also be legislation in place to help with this. If you have a fragile African penguin population, you might want to consider restricting the number of visitors for the benefit of these birds.”
The scientists, however, also recognise that tourism is important for wildlife conservation, which is why they are suggesting access to colonies be guided and that tour guides be informed of what they can and cannot do to lessen the impact on the colonies.
This includes not taking visitors too close to the penguins.
“Although the results of this study are crucial for developing enhanced conservation and management protocols, additional research on the long-term effect of human activities on African penguin physiology is required,” Scheun said.
Ganswindt said while a more comprehensive study will be necessary to gauge the impact on the African penguin population level, these shorter examinations already show that human presence is usually not well perceived by wildlife.
“For ongoing conservation purposes it would be helpful to monitor the long-term effects of the stress responses of various ages in this species, as stress physiology may change during development.
“For example, an adult penguin might perceive human disturbance differently when exposed to a stressor than a sub-adult or a chick.”
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