The Different Physical and Behavioural Characteristics of Zoo Mammals That Influence Their Response to Visitors

SIMPLE SUMMARY: Studies of the zoo visitor effect (changes in animal behaviour in response to the presence of the public) have had varying results: most studies have found that visitors have a negative animal welfare impact, but some studies have found no effect, or even, a positive effect on animal welfare. The problem is that most studies only consider one species at a time and meta-analyses suffer from the great variation in animal husbandry, enclosures and the public’s behaviour. Therefore, we examined 17 different mammal species responses to zoo visitors over the period of one year. The species were chosen to show a variation in physical characteristics (e.g., body weight) and habits (e.g., diurnal or nocturnal); this allows us to determine which characteristics are important in determining the variation of the response of mammals to zoo visitors. The results showed no effect of body weight, but activity cycle was very important, with diurnal animals being more affected. These results allow us to predict which mammal species will be most negatively affected by zoo visitor presence. ABSTRACT: The factors underlying the ‘zoo visit effect’ (changes in animal behaviour/physiology in response to visitor presence) are still poorly understood, despite it being widely investigated. The present study examined the effect of zoo visitors on the behaviour of 17 different species of mammals at the Belo Horizonte Zoo, Minas Gerais, Brazil. The behaviour of the animals was recorded using scan (focal in one case) sampling with instantaneous recording of behaviour, during 12 continuous months. Data were analysed using a comparative method examining five different factors: diet, body weight, stratum occupied, activity cycle, and habitat, as well as three different visitor categories: small and quiet audience, medium size audience and medium noise, and large size and loud audience. Significant changes in the behaviour for each factor, especially increases in locomotor and resting behaviour, were observed in response to different visitor categories. The factors that most explained responses to visitor categories were habitat and activity cycle. Species from closed habitats compared to open habitats were significantly more impacted (more behaviour affected), probably, because they are, evolutionarily, less accustomed to visual contact with people. Diurnal species showed more behavioural changes than nocturnal ones, possibly, because they were being observed during their normal activity cycle. These results may help zoos identify which mammal species are most susceptible to the zoo visitor effect, and consequently, be more pro-active in the use of mitigating strategies.