CAPE TOWN - A study by a team of scientists led by the University of Pretoria (UP) has revealed that the close interaction of tourists with African penguin chicks could cause stress among the birds.
The stress could result in immunosuppression, leaving them susceptible to disease, while their reproduction ability could be reduced.
The endangered African penguin is found in South Africa 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 the threat of extinction.
The study – titled “Urofaecal glucocorticoid metabolite (ufGCM) concentrations in African penguin (Spheniscus demersus) chick populations experiencing different levels of human disturbance” – was recently published in the journal Conservation Physiology. It involved the work of Dr Juan Scheun, a research fellow at the Mammal Research Institute at UP; Professor Andre Ganswindt, Director of the institute; and scientists from Exeter University in the UK, the University of the Western Cape and Nelson Mandela University.
“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,” Scheun said. “Both had varying levels of exposure to tourism.”
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 African penguin in 1982 and became one of the largest breeding colonies in South Africa. 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,” 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 responsible for the increase in stress-related hormone levels in chicks. Other factors, like food shortages, may also be contributing to these elevated levels.
The presence of overzealous tourists at the penguin breeding colonies, in particular, 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,” Scheun and Ganswindt said.
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 well-being of these chicks, the experts are calling for a limitation on the number of tourists who visit these penguin 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,” they said.
The scientists, however, also recognise that tourism is important for wildlife conservation, which is why they are suggesting that access to colonies be guided, and that tour guides be informed of what they can and cannot do in order to lessen the impact on the bird colony. This includes not taking visitors too close to the penguins.