Abstract:
Despite the importance of ecotourism in species conservation, little is known about the industry’s effects on wildlife. In
South Africa, some African penguin (Spheniscus demersus) colonies have become tourist attractions. The species is globally
endangered, with population sizes decreasing over the past 40 years. As African penguin chicks are altricial and unable to move
away from anthropogenic stressors, it is important to evaluate the effect of tourist activities on baseline glucocorticoid levels as
a measure of potential disturbance. Chicks at three study sites within two breeding colonies (Robben Island, Stony Point), with
varying levels of exposure to tourism (low/moderate/high) were monitored. Urofaecal samples were collected to determine
urofaecal glucocorticoid metabolite (ufGCM) concentrations as an indication of baseline stress physiology. Morphometric
measurements were taken to compare body condition between sites. Penguin chicks experiencing low, infrequent human
presence had significantly higher mean (± standard deviation) ufGCM levels [1.34 ± 1.70 μg/g dry weight (DW)] compared
to chicks experiencing both medium (0.50 ± 0.40 μg/g DW, P = 0.001) and high levels of human presence (0.57 ± 0.47 μg/g
DW, P = 0.003). There was no difference in chick body condition across sites. These results suggest that exposure to frequent
human activity may induce habituation/desensitization in African penguin chicks. Acute, infrequent human presence was
likely an important driver for comparatively higher ufGCM levels in chicks, though several other environmental stressors may
also play an important role in driving adrenocortical activity. Nevertheless, as unhabituated chicks experiencing infrequent
anthropogenic presence showed significantly higher ufGCM levels, managers and legislation should attempt to minimize all
forms of activity around important breeding colonies that are not already exposed to regular tourism. Although the results of
this study are crucial for developing enhanced conservation and management protocols, additional research on the long-term
effect of anthropogenic activities on African penguin physiology is required.
