Special Issue "Human Influences on the Behaviour and Welfare of Zoo Animals"

A special issue of Animals (ISSN 2076-2615). This special issue belongs to the section "Wildlife".

Deadline for manuscript submissions: 30 April 2019

Special Issue Editor

Guest Editor
Prof. Paul Hemsworth

Animal Welfare Science Centre, University of Melbourne, Parkville, Australia
Website | E-Mail
Interests: Animal welfare; animal behaviour; farm and companion animals; human-animal interactions

Special Issue Information

Dear Colleagues,

Since the 1980s there has been an ever-increasing body of evidence accumulating on the profound effects of human-animal interactions on the behaviour and stress physiology of animals in captivity, particularly farm animals. This extensive research in the livestock industries indicates that the history of human interactions with their farm animals leads to a stimulus-specific response in farm animals to humans. In addition to the animal’s experiences, characteristics of the animal, such as age, social environment and genetics, also affect their response to humans. Importantly, the animal’s perception of humans has implications for its welfare, as emotions in animals are generated by human interactions.

Surprisingly, less research has been conducted on the human-animal relationship in other animal use settings in which there is substantial human contact, such as zoos. There is developing literature on the effects of human interactions on zoo animals. The most robust evidence is that contact with visitors in the visitor viewing area may be perceived as negative, neutral or even positive, depending on the species, the visitor behaviour and characteristics of the animal enclosure that may affect how the animal perceives human visitors. There is limited evidence that the keeper-zoo animal relationship may be related to the behaviour, welfare and reproductive success of some zoo species, clearly with more research needed in this area. An emerging and contentious aspect of modern visitor-zoo animal interactions is the offering of what can be referred to as ‘close encounters’, these typically involve an additional paid experience where visitors can feed or touch animals under the supervisior of zoo officials. But the impact of these enocunters on both animal welfare and visitor experience has received little research attention to date.

The aim of this Special Issue is to present recent research and reviews on the implications of human-zoo animal interactions on zoo animal behaviour and welfare, with the aim of stimulating interest, understanding and exploration of this important subject.

Prof. Paul Hemsworth
Guest Editor

Manuscript Submission Information

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  • human-animal interactions
  • zoo animals
  • zoo keepers
  • zoo visitors
  • behaviour
  • welfare

Published Papers

This special issue is now open for submission, see below for planned papers.

Planned Papers

The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.

Title: Effects of Manipulating Visitor Proximity and the Intensity of Visitor Behaviours on Little Penguin (Eudyptula minor) Behaviour and Welfare
Authors: Samantha J. Chiew, Kym L. Butler, Sally L. Sherwen, Grahame J. Coleman, Vicky Melfi, Kerry V. Fanson, and Paul H. Hemsworth
Abstract: This experiment examined the effects of manipulating the viewing proximity of visitors and the intensity of visitor behaviours on fear behaviour of 15 zoo-housed little penguins (Eudyptula minor). A 2×2 factorial fully randomised design, with an added control where the exhibit was closed to visitors (‘Exhibit closed’), was used to examine two main factors at two levels: 1. Viewing proximity of visitors to enclosure: ‘Normal viewing proximity’ and ’Increased distance from enclosure’ (2m from enclosure) and 2. Intensity of visitor behaviours: ‘Unregulated visitor behaviour’ and ‘Regulated visitor behaviour’ (using signage and uniformed personnel). Each treatment was randomly imposed for 2-day periods with three replicates of each treatment (total of 30 study days). Penguin behaviour and visitor numbers and behaviour were recorded from CCTB video recordings and direct observations, respectively. Penguin faecal glucocorticoid metabolites (FGM) were also analysed as a measure of stress physiology. Data were analysed using the general analysis of variance for a fully randomised factorial design, with an added external control. Increasing visitor viewing distance from the enclosure reduced (P<0.05) all visitor behaviours except shouts/screams. When visitors were further away, the proportion of penguins huddling (p=0.0016), idle (p=0.041) and vigilant (p=0.044) decreased and the proportion of penguins within 1 m of the visitor viewing area (p=0.0028) and surface swimming (p=0.0017) increased. Also, when visitors were further away, the proportion of penguins preening in the water increased (p=0.019), while the proportion of penguins pecking (p=0.029), fleeing (p=0.046) and retreating (p=0.000061) decreased. The effects of regulating visitor behaviour were relatively limited. No interaction was found between the main effects (p>0.05) and no effect of treatment on the stress physiology of little penguins (p>0.05) was found. These results indicate that visitor viewing proximity affects fear behaviour of penguins but there was no sustained or prolonged change in stress physiology that was indicative of stress. Thus, close visitor contact can be fear-provoking for little penguins but these results in this enclosure demonstrate that a physical barrier to increase the distance between visitors and penguins, reduces fear responses in little penguins. However, it is not clear whether this reduction in fear responses is due to the increased separation of visitors from the penguins when visitors are further away and/or specific visitor behaviours associated with close proximity to the enclosure, such as leaning over the enclosure or tactile contact with the pool, that increased fear-responses in penguins. Further research is required to determine this.

Title: Japanese Macaque Rank is a Predictor of Aggression Toward Zoo Visitors
Authors: Jocelyn M. Woods, Stephen R. Ross, Katherine A. Cronin
Abstract: The effect that visitors have on the behavior and welfare of animals is a widely-studied topic in zoo animal welfare. Typically, these studies focus on how the presence or activity levels of visitors affect the behavior of primates. However, for many species, and particularly primates, social rank can also have a large impact on behavior. Here, we considered the influence of both environmental factors such as crowd size and activity levels and individual differences, specifically individual rank, on the occurrence of visitor-directed aggression by zoo-housed Japanese macaques (Macaca fuscata, N=12). We hypothesized that individual rank would predict the frequency of visitor-directed aggression with lower-ranking individuals more often redirecting aggression to visitors as safe targets. We conducted 52 weeks of observations (488.8 hours) on macaques living in a large, outdoor habitat and calculated rank weekly using the Elo-rating method, which provides a continuously-updated ranking score that is impacted by the sequence in which interactions occur. GLMM Full-null model comparisons indicated rank as a significant predictor of visitor-directed aggression (X2 = 29.4, p < 0.001), with lower-ranked individuals displaying more frequent aggression towards visitors. Additionally, visitor-directed aggression differed by crowd activity levels (p = 0.02), but not crowd size (p = 0.68). These results support our prediction that rank is associated with differences in visitor-directed aggression, and we interpret this pattern as lower-ranking macaques redirecting aggression toward zoo visitors. This work emphasizes how environmental factors and individual differences can combine to influence primate response to human presence.

Title: Effects of Hand-Rearing on the Behaviour and Welfare of Zoo Chimpanzees (Pan troglodytes)
Authors: Caterina Spiezio1, Stefano Vaglio1,2,3,*, Camille Vandelle 4 and Barbara Regaiolli 1
1 Research & Conservation Department, Parco Natura Viva - Garda Zoological Park, Bussolengo (VR), Italy.
2 Department of Biology, Chemistry and Forensic Science, University of Wolverhampton, Wolverhampton, UK.
3 Department of Anthropology & Behaviour, Ecology and Evolution Research (BEER) Centre, Durham University, Durham, UK.
4 Facultè de Medicinè Vètèrinaire, Université de Liège, Liège, Belgium.
* Corresponding Author: [email protected]  Tel.: +44 (0) 1902 323328 
Abstract: Early-life experiences may considerably impact the behaviour of adult primates and influence how they interact with their environment. In particular, hand-rearing practices might lead to stereotypic behaviours as well as to social-sexual incompetence in non-human primates. This study aimed to compare the behaviour of hand-reared and parent-reared zoo chimpanzees (Pan troglodytes), particularly focusing on welfare implications. We studied 11 chimpanzees, six parent-reared and five hand-reared, living in a social group at Parco Natura Viva, Italy. We used continuous focal animal sampling to collect behavioural data on chimpanzee individual and social behaviours. All study subjects performed individual and social species-specific behaviours. However, hand-reared chimpanzees also showed abnormal behaviours. Parent-reared chimpanzees performed both locomotion and social resting more frequently than hand-reared individuals. Our findings suggest that early-life experience could affect the behavioural development of chimpanzees, leading to the performance of abnormal behaviours. However, managing hand-reared chimpanzees in adequate social housing and enriched environments might mitigate the effects of unnatural early-life experiences, promoting species-specific behaviours and reducing the behavioural gap between hand-reared and parent-reared individuals.

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