Effects of visitors and cage changes on the behaviors of mangabeys

Abstract

Three groups of golden-bellied mangabeys were studied to determine the effects of visitors and cage changes on their aggressive displays, grooming and sexual behavior, and play. Assessments of changes in behavior were made by comparing categorized observer comments. Animals moved to cages having more visitors increased their aggressive displays toward people, decreased their aggressive displays toward other species in neighboring cages, and increased their withingroup aggression. On the other hand, grooming, sexual behavior, and play increased after cage changes regardless of numbers of visitors. The view that it is the puttern of behavior changes in enrichment that is important in assessment of attempted enrichment was supported. Aggressive and affiliative behaviors are affected quite differently by different environmental stimuli in the zoo.

The visitor effect in petting zoo-housed animals: Aversive or enriching?

“…While visitors can hypothetically be a negative, neutral, or positive influence on zoo animals (Hosey, 2000), the most common behavioural changes reported are generally interpreted as negative in terms of animal welfare. These include decreased social behaviour (Chamove et al, 1988, Glatston et al, 1984, Mallapur et al, 2005, Wood, 1998, increased abnormal behaviour (Blaney and Wells, 2004, Chamove et al, 1988, Mallapur and Chellam, 2002, Mallapur et al, 2005, Skyner et al, 2004, Wells, 2005 and increased aggression (Blaney and Wells, 2004, Chamove et al,1 988, Glatston et al, 1984, Kuhar, 2008, Mitchell et al, 1991, Wells, 2005. More recently, physiological changes indicative of decreased welfare have been reported in relationship to visitor-related variables in spider monkeys (Ateles geoffroyii rufiventris; Davis et al, 2005) and black rhinoceros (Dicornis bicornis; Carlstead and Brown, 2005).…”

“…In addition to the presence or absence of visitors, the number of visitors appears to have a measureable effect on the behaviour of captive primate species (Birke, 2002, Chamove et al, 1988, Cooke and Schillaci, 2007, Fa, 1989, Glatston, 1984, Hosey and Druck, 1987, Kuhar, 2008, Mitchell et al, 1991, Skyner et al, 2004, Todd et al, 2006, Wells, 2005, Wood, 1998 and this variable is the most frequently reported in the literature. It is less clear whether there is a visitor density effect on other mammals commonly housed in zoos, due in part to the relatively few visitor effect studies carried out on non-primates.…”

The “Visitor Effect”

“…Hosey argued that if the latter was true then captive animals housed in accommodation that was both exposed to, and away from, visitors would not show significant differences in behaviour. The literature shows that this prediction is clearly not true (Glaston, et al 1984;Mitchell et al, 1991;Chamove et al, 1988). In other words, evidence seems to imply that it is the audience that causes changes in animal behaviour and not vice versa, although Hosey suggested that there is probably an element of both forces to some degree (with the visitor effect dominating).…”

“…Hosey & Druck (1987) observed higher levels of primate behaviour in the presence of large groups of visitors compared to smaller groups. Mitchell et al (1991) found that animals displayed increased aggression towards visitors, and decreased aggression towards other species in neighbouring cages, when visitor density was high. Mitchell et al (1991) moved Golden-bellied Mangabeys from a cage associated with high visitor attendance to one with lower visitor numbers, and found that aggression within the group decreased, but threats towards primates in neighbouring cages increased.…”

“…Mitchell et al (1991) found that animals displayed increased aggression towards visitors, and decreased aggression towards other species in neighbouring cages, when visitor density was high. Mitchell et al (1991) moved Golden-bellied Mangabeys from a cage associated with high visitor attendance to one with lower visitor numbers, and found that aggression within the group decreased, but threats towards primates in neighbouring cages increased. Fa (1986) found that the birth rate of macaque troops decreased as the number of visitors increased.…”