Zoo visitor effect on mammal behaviour: Does noise matter?

Abstract

a b s t r a c tThe zoo visitor effect is the change in animal behaviour and physiology in response to the presence of a viewing public. It is thought to result from, amongst other things, visitor generated sound (i.e., noise), but this hypothesis has never been explicitly tested. We tested this hypothesis through observations on the behaviour and enclosure use of 12 mammal species held in 12 separate enclosures at the Belo Horizonte Zoo when exposed to different sound pressure levels (i.e., noise) from the visiting public. Noise pollution levels were significantly higher with the public present and increased with increasing audience size. Species that are more popular suffered greater noise pollution from the zoo visitors. No overall effects on behaviour were found in relation to noise levels, however, analysis of behaviour at the individual level found some significant differences. Notably, half of the individuals increased their vigilance behaviour with increasing sound levels and approximately onethird of individuals increased their movements. These results show that zoo visitors have a negative welfare impact on individual zoo-housed mammals, especially groups of noisy visitors where levels were recorded outside of the recommended limits for human wellbeing (>70 dB(A)). Thus, zoos need to address this issue, probably, through a combination of visitor education campaigns and acoustic modification to enclosures.

Evaluating mood changes in response to anthropogenic noise with a response-slowing task in three species of zoo-housed primates

“…In the zoo environment anthropogenic noise is common, as sound levels may increase due to visitors, construction, habitat design, and special events. Past studies have evaluated how various sources of noise in the zoo environment influence behavioral and physiological indicators of welfare in a variety of species (e.g., Birke, 2002;Chosy, Wilson, & Santymire, 2014;Davey, 2007;Kight & Swaddle, 2011;Orban, Soltis, Perkins, & Mellen, 2017;Quadros, Goulart, Passos, Vecci, & Young, 2014).…”

A note on the effect of concerts on the behaviour of Domestic dogs Canis lupus familiaris at Taronga Zoo, Sydney

“…This effect was not found when similar numbers of visitors watched the animals quietly. Larsen et al (2014) (Quadros et al, 2014). Sherwen et al (2014) showed no change in Slender-tailed meerkat Suricata suricatta behaviour when visitor noise was reduced.…”

“…() showed that Koalas Phascolarctos cinereus increased their vigilance behaviour in response to visitor noise. A study of 12 mammal species [Brown howler monkey Alouatta guariba , Golden‐headed lion tamarin Leontopithecus chrysomelas , Chimpanzee Pan troglodytes , Gorilla Gorilla gorilla , Yellow breasted capuchin Cebus ( Sapajus ) xanthosternos , Jaguar Panthera onca , Ocelot Leopardus pardalis , Bush dog Speothos venaticus , African elephant Loxodonta africana , Giraffe Giraffa camelopardalis , Waterbuck Kobus ellipsiprymnus , Red deer Cervus elaphus ] in 12 enclosures at Belo Horizonte Zoo in Brazil found mixed results where some animals increased their vigilance in response to greater visitor pressure, although in this case noise was not independent of visitor numbers (Quadros et al ., ). Sherwen et al .…”

Zoo foraging ecology: Preference and welfare assessment of two okapi (Okapia johnstoni) at the Brookfield Zoo.

“…Unlike the female, however, the majority of food patches with the highest GUDs were located either along the visitor area or toward the back of the exhibit. Previous studies suggest that visitor proximity may negatively impact zoo animal behavior and welfare (see Davey, 2007 for a review ;Quadros, Goulart, Passos, Vecci, & Young, 2014;Suárez, Recuerda, & Arias-de-Reyna, 2017); it is therefore possible that the male okapi was more sensitive and possibly threatened by the proximity of human visitors compared to the female. This idea could be tested further by adding additional visual barriers or canopy cover along the exhibit barrier between the visitors and the okapi.…”