The visitor effect: an investigation into the impact of visitors on the behaviour and welfare of zoo animals

© 2015 Dr. Sally SherwenAchieving and maintaining high standards of animal welfare are critical to the success of a modern zoo. Research has shown that an animal’s welfare can be strongly affected by the zoo environment. A major part of this environment for zoo animals is the regular presence of unfamiliar human visitors watching, and sometimes actively seeking interaction. Despite considerable research in human-animal interactions in domestic animals, there has been only limited work in this area in the zoo setting. Consequently, many questions remain about the impact of visitors on zoo animal behaviour and welfare. Previous studies in this field have been restricted by methodological challenges including difficulty in conducting experiments in situ to determine cause and effect and limitations in the diversity of taxonomic groups studied. This research was designed to enhance our understanding of visitor effects in zoo animals to ultimately provide zoos with practical animal management and enclosure design strategies to safeguard animal welfare. This thesis is presented as a series of four studies conducted on different species housed at Zoos Victoria properties (Melbourne Zoo, Werribee Open Range Zoo and Healesville Sanctuary, all in Victoria, Australia). The first study is an investigation into the effects of visitor number on the behaviour and stress physiology of Kangaroo Island (KI) kangaroos and red kangaroos housed in two free range exhibits. Results showed that when visitor number increased, both KI kangaroos and red kangaroos increased the time spent engaged in visitor-directed vigilance and KI kangaroos also decreased the time spent resting. However, there was no effect of visitor number on the distance kangaroos positioned themselves from the visitor pathway or faecal glucocorticoid (GC) metabolite concentration in either species. These findings provide little evidence of adverse effects on animal welfare in these study groups. It is likely that the provision of retreat areas in these exhibits contributes to their ability to cope, however this is an area of interest for future research. The second study focused on three groups of meerkats housed at two zoos, with the aim of investigating the effect of experimentally reducing intensity of visitor behavior (including noise level). This was achieved by using signage and the presence of zoo personnel asking visitors to be quiet and not interact with the animals. This method effectively reduced visitor noise by around 32% at exhibits as well as effectively reducing the score of visitor behavior intensity. However, meerkats did not adjust their behaviour in response to this change in visitor conditions, suggesting that these groups of meerkats were coping well within the range of visitor conditions to which they were exposed. The aim of the third study was to investigate visitor effects in little penguins. Several studies have shown that human disturbance can have negative impacts on wild penguin populations, yet visitor effects on zoo penguin behaviour had not previously been investigated. Penguin behaviour was studied under two experimental conditions 1) no visitor contact, which was achieved by closing the exhibit and 2) exposure to visitors, with the exhibit open as usual. When exposed to visitors, penguins showed increased levels of aggression, huddling and avoidance including increased time spent behind enclosure features and increased distance from visitors. These behavioural results suggest that the presence of visitors may have been fear-provoking for the penguins, however further research is required to investigate what visitor characteristics are responsible for this effect. The final study aimed to investigate the effects of visual contact with visitors on black-capped capuchin behaviour and welfare. Several previous studies on visitor effects in primate species found that visitor presence increased aggression and abnormal behaviour in primates. To investigate this further, I manipulated visual contact using one-way vision screens and analysed capuchin behaviour and faecal GC metabolite concentrations. Results showed that aggression, avoidance and GC concentrations were reduced when the capuchins’ view of visitors was obscured. These findings highlight that physical changes to an animal’s enclosure may ameliorate negative impacts from visitors and as a result, improve animal welfare. The research in this thesis highlights that understanding the effects of human-animal interactions on zoo animals provides opportunities where necessary to improve zoo animal welfare, which will ultimately enhance the support of zoos and their role in species conservation