Why the "Visitor Effect" Is Complicated. Unraveling Individual Animal, Visitor Number, and Climatic Influences on Behavior, Space Use and Interactions With Keepers-A Case Study on Captive Hornbills

Keeper effect: Animals are more active in the presence of their caretakers

Zookeepers are the primary caretakers of animals, providing daily care through frequent and close interactions. From the animal's perspective, most of these daily interactions are likely to have positive outcomes. With consistent and reliable interactions, a human-animal relationship is expected to develop. Our aim of this study was to investigate if the presence of the primary keeper in the public viewing area of zoo exhibits impacts the behavior of animals. We observed the behavior of 15 individuals of six species in the presence and absence of their primary keeper. Overall, we observed animals being more active in their keeper's presence than when the keeper was not present. When we considered if the keeper was nearby around times of offered opportunities to animals (e.g., feeding, enrichment, and training), our results showed that animals were equally as active when the keeper was present before an opportunity and when no opportunity was offered. These equal activity levels imply that the keeper is a cue for a forthcoming event to the animals, which reflects anticipatory behavior. Overall, we demonstrate that keeper presence is an environmental context in which animals behave differently than in keeper absence.

A preliminary global investigation into potential impacts on successful captive breeding for two species of Rhyticeros hornbill

Asian hornbills have limited ex situ breeding success, yet these species are some of the most threatened of birds, in need of managed breeding programs. To optimize breeding and increase the sustainability of such populations, it is necessary to assess and improve their husbandry and welfare. Evidence to improve reproduction can be gathered through global husbandry surveys. A survey was sent out to all European Association of Zoos and Aquaria and Association of Zoos and Aquarium holders of the wreathed hornbill (Rhyticeros undulatus) and Papuan hornbill (R. plicatus) to determine predictors for ex situ breeding success. This research found that pairs that have spent more years together (p = .016) and that adding additional proteins to the diet (p = .006) are two significant predictors of breeding success for wreathed- and Papuan hornbill pairs. This paper found a general trend that successful hornbill pairs prefer nest boxes that are situated outside (p = .054). The behaviors of calling to each other and sitting in close proximity showed a general trend and were observed more frequently in successful pairs and, therefore, could be good indicators of bonded pairs. We recommend that ex situ institutions allow their hornbill pairs time to form strong bonds, and that pair compatibility is monitored regularly to ensure that such interactions are positive and not consistently negative. An increase in the percentage of dietary proteins, prior and during the breeding season appears to stimulate pairs to breed. If the management and husbandry alterations presented in this study are implemented, the sustainability of Rhyticeros hornbill populations may be enhanced.

Establishing New Isosexual Pairs in Adult Male Guinea Pigs (Cavia porcellus) to Facilitate Social Housing

Guinea pigs (Cavia porcellus) are a commonly used species in biomedical research. As social creatures, compatible guinea pigs should be housed together unless scientific objectives or veterinary care require otherwise. Extensive literature suggests that adult male guinea pigs are highly aggressive in the presence of females, but data are lacking regarding the compatibility of cohoused adult males in the absence of females. Most studies that use adult males do not report housing densities. We used serial wound scoring and observations of behavior to determine whether unfamiliar adult male guinea pigs will develop stable, prosocial isosexual pairs. Wound scoring was performed before and 24 h after pairing. Serial behavioral observations assessed affiliative and agonistic behaviors at 0.5, 2, 24, and 48 h after pairing. Wound scoring and behavioral observations continued weekly for 1 mo and monthly thereafter. Wound scores were significantly higher at 24 h after pairing as compared with baseline and all other time points. Wounding was rare after week 2, indicating reduced aggression. Furthermore, affiliative behaviors significantly increased over time while agonistic behaviors were rare. Together, these data suggest that unfamiliar adult male guinea pigs establish stable prosocial pairs after an acclimation period. As was done in the present study, providing ample space, separate shelters for each animal, and the absence of female guinea pigs will likely facilitate successful pairing. We recommend consideration of a social housing program for adult male guinea pigs to provide companionship and enrich their housing environment.

Assessing the impact of environmental enrichment on behavior in understudied armadillo species: A case study

The implementation of environmental enrichment (EE) can be effective in promoting zoo animal welfare by enhancing the performance of natural or species-typical behaviors. Research on the effects of EE is biased towards larger mammalian species, with less charismatic species being overlooked. Armadillos are one such overlooked example. A captive environment that results in inactivity, obesity, and associated poor health can negatively affect armadillo well-being. The aim of this study was to evaluate how the implementation of four physical object-based EEs could positively affect the behaviors of three armadillo species, housed in four similar exhibits. Behavioral data were collected both before (baseline) and during (treatment) EE periods, alongside of visitor number and environmental temperatures. The EE comprised of a plastic ball or a cardboard tube or a cardboard box, or a scatter-feed, and these were rotated each week of study until each exhibit had received them in turn. Despite the presence of different EE types, activity remained low throughout the study. However, results suggest that the plastic ball and cardboard box increased exploratory behaviors in the armadillos, but no overall increase in activity was noted during the scatter feed. Visitor presence had no effect on armadillo activity, and armadillos showed reduced activity with increasing environmental temperature. Overall, the use of physical object-based EE promoted beneficial natural behaviors in zoo-housed armadillos, but environmental conditions (i.e., temperature) also impacted armadillo activity, suggesting a complicated relationship between an enclosure's environmental variable and any behavioral husbandry measures.

Aquarium Visitors Catch Some Rays: Rays Are More Active in the Presence of More Visitors

Humans are a constant in the lives of captive animals, but the effects of human-animal interactions vary. Research on the welfare impacts of human-animal interactions focus predominantly on mammals, whereas fish have been overlooked. To address this lack of research, we assessed the impacts of aquarium visitors on the behaviors of ten members of four elasmobranch species: an Atlantic stingray (Dasyatis sabina), four southern stingrays (Hypanus americanus), two blue-spotted maskrays (Neotrygon kuhlii), and three fiddler rays (Trygonorrhina dumerilii). The rays engaged in a significantly higher proportion of active behaviors and a lower proportion of inactive behaviors when visitor density levels were high; however, there were no significant changes for negative or social behaviors. Individual analyses indicated that all three fiddler rays and one of the southern stingrays' active behaviors differed across visitor density levels, whereas there was no association between active behavior and visitor density levels for the other rays. Further research is needed to determine whether this pattern is an adaptive or maladaptive response to visitors, but this research provides much needed initial data on activity budgets within elasmobranch species.

Do not disturb: Visitors' effect on the behavior and welfare of female and male big cats in zoos

The effect of visitor presence on animal behavior needs to be evaluated to ensure the welfare and improve the husbandry of the individuals in zoos. This study aims to assess the effect of visitor presence on the behavior and welfare of pairs of Amur tiger, snow leopard, and Eurasian lynx at Parco Natura Viva, Italy. The study was made of two periods: the baseline, in which the zoo was closed, and the visitor presence period, in which the zoo was opened. Per period and per subject 12 30-min observations were done. Continuous focal animal sampling method was used to collect behavior duration of the big cats. The main results of the study highlighted that, when visitors were present, all felids except for the female lynx were significantly more inactive than in the baseline. Moreover, despite interindividual and inter-species variability in the significance level of findings, natural behaviors such as attentive behavior, exploration/marking, locomotion, and positive social interactions were performed more in the baseline than in the visitor presence period. Finally, when visitors were present, as the studied subjects experienced daily longer exposure to visitors, inactivity increased whereas individual species-typical behaviors (e.g., locomotion) and positive social interactions decreased. Thus, visitors seem to partially alter the behavioral time-budgets of the study big cats, increasing inactivity and decreasing the performance of species-specific behavior, at least in some individuals.

The Integrated Effect of Environmental Conditions and Human Presence on the Behaviour of a Pair of Zoo-Housed Asian Small-Clawed Otters

Zoos and aquaria have the ethical responsibility to provide animals under their care with conditions that promote good welfare. This study evaluated the combined influence of human presence and environmental factors on the behaviour of zoo-housed Asian small-clawed otters (Aonyx cinereus). Data collection was conducted on a pair hosted at Pistoia Zoo (Italy). Data were collected from July to September 2020 (over 14 days). We video-recorded the otters' behaviours, using the continuous focal animal sampling, obtaining 42 h of observation per subject. The otters displayed a wide array of species-specific behaviours. Compared to previous captive studies, the subjects engaged less in locomotion, food-related and affiliative behaviours, and more in vigilance. Human-animal interactions were limited, and mostly elicited neutral or positive responses, except for begging behaviours performed towards caregivers. Time of day and animal identity were the main significant predictors for behaviours. No effects of visitor presence or background noise were detected. Nonetheless, increasing enrichment use could stimulate food-related behaviours, and reduce vigilance and begging. This study confirms the importance of applying an integrated approach to analyse the complexity of otters' experiences, and provides insights to guide husbandry improvements.

Visitors and observers otter-ly influence the behavior and enclosure use of zoo-housed giant otters

The potential impact of human presence on captive animal behavior has recently been the focus of considerable research interest, especially following 2020 and 2021 periods of enforced closure as a result of COVID-19 opening restrictions. It is important to investigate whether human presence represents an enriching or stressful stimulus to a range of zoo-housed species. In 2020, during an easing of lockdown restrictions, investigations of the "visitor effect" and "observer effect" were carried out, using the giant otter (Pteronura brasiliensis) as a model species. To investigate the impact of both visitor and observer presence, otter behavior and space use was recorded for a pair of on-show and a pair of off-show otters. Observations were conducted using either a human observer, or cameras, allowing the researchers to investigate otter behavior when no one was present at the exhibits. The Electivity Index was used to assess the otters' use of four enclosure zones. Overall, otter behavior was significantly impacted by observer presence, though the impact of an observer differed between individual otters. Visitors had a minimal effect on otter enclosure use, whereas observers had a greater impact, whereby otters used their pools less frequently and houses more frequently when observers were present. However, this change in zone use differed between individuals, with more dominant otters tending to make use of indoor zones more often when observers were present. Zoos should consider the potential impact of human presence on their animals and use both behavior and space use when conducting their investigations.

The Impact of Visitors on Non-Primate Species in Zoos: A Quantitative Review

Visitors are a prominent feature in the lives of zoo animals, and their presence can cause a range of impacts on zoo animals (typically classed as positive, negative or neutral impacts), commonly referred to as the ‘visitor effect’. This paper quantitatively collates the literature on the visitor effect in non-primate species, investigates the types of measures used to assess impacts of visitors on animals and considers whether impacts vary across non-primate species in zoos. In total, there were 105 papers which had investigated the impact of zoo visitors on 252 non-primate species/species groups. There has been a steady increase in visitor effect research in zoos since 2012 and this body of work incorporates species from avian (28% study species), reptilian (9%), amphibian (2%), fish (4%) and invertebrate taxa (1%). However, there is still a bias towards mammalian species (56%). The response to visitors varied across taxa. Amphibians responded negatively to visitors more frequently than would be expected by chance (p < 0.05), birds responded neutrally more frequently than would be expected by chance (p < 0.05) and fish responded neutrally and ‘unknown’ more frequently than would be expected by chance (p < 0.05). This review highlighted a number of animal-based metrics which have been used to assess the impacts of visitors on animals, with measures used varying across taxa. Moving forwards, it is recommended that moving forwards researchers incorporate a suite of measures, incorporating those which are meaningful in terms of being representative of individual animal experiences and animal welfare, collected in a manner which should capture those metrics accurately.

Do zoo-housed primates retreat from crowds? A simple study of five primate species

An animal's welfare state is directly influenced by the mental state, which is shaped by experiences within the environment throughout the animal's life. For zoo-housed animals, visitors to the zoo are a large part of that environment and a fluctuating influence within it. This study examines the impact of zoo visitors on the space use of five species of zoo-housed primates (Eastern black-and-white colobus monkeys, Colobus guereza, n = 5, Allen's swamp monkeys, Allenopithecus nigroviridis, n = 2, DeBrazza's monkeys, Cercopithecus neglectus, n = 3, Bolivian gray titi monkeys, Callicebus donacophilus, n = 3, and crowned lemurs, Eulemur coronatus, n = 3). Specifically, we considered whether primates' distance from visitor areas changed as crowd sizes increased. Data were collected using the ZooMonitor app. Observers recorded spatial coordinates for each animal over periods ranging from 12 to 32 months. Data were analyzed using two types of regression models (linear and logistic) to examine the influence of visitors on the location of the primates. Both analyses revealed a statistically significant but small decrease in primate distance from visitor viewing glass as the number of visitors increased. Behavioral indicators of welfare were also unaffected by the presence of visitors. These results suggest that, with additional validation, distance from visitors may be one promising, simple way to evaluate the influence of visitors on primate welfare.

Dither: A unifying model of the effects of visitor numbers on zoo animal behavior

Interest in the impact of human presence on the behavior and well-being of zoo and aquarium animals is increasing. Previous work has conceptualized the presence of zoo visitors as having one of three impacts on the behavior of animals in zoos: positive, negative, or neutral. Research suggests the same species may exhibit all three responses under different conditions, calling into question whether the positive/negative/neutral framework is the most useful way of considering visitor impact on animal behavior. Here we present a model of visitor effects that unifies these three predictions. Our model suggests that zoo-goers may provide a "dither effect" for some animals living in zoos. We posit animals may show nonlinear behavioral responses over a range of visitor densities, effectively exhibiting changes in both comfortable and anxiety-like behaviors under different levels of human presence. We tested this model during two COVID-19 related closures at the San Francisco Zoo, studying seven species for evidence of nonlinear relationships between visitor numbers and animal behavior. Our results support the dither effect acting in several species observed.

Environmental and Social Influences on the Behaviour of Free-Living Mandarin Ducks in Richmond Park

Simple Summary

Collecting information on how wild animals behave in the free-living environment can be useful for improving how such species are managed when under human care (e.g., in the zoo). Mandarin Ducks are an example of a species with a large captive population where research into the behaviour of wild birds can help with explaining and evaluating how this species is coping in captivity. This research collected data on free-living Mandarins in a large public park and compared such data to published research on captive Mandarins to evaluate any differences in time budgets. The overall aim of this research was to provide information on what behaviours are commonest amongst free-living Mandarin Ducks to help others with the assessment of behavioural normality of captive birds.

Abstract

Many species of birds are housed in zoos globally and are some of the most popular of animals kept under human care. Careful observations of how species live and behave in their natural habitats can provide us with important knowledge about their needs, adaptations, and internal states, allowing identification of those behaviours that are most important to the individual’s physical health and wellbeing. For this study, Mandarin Ducks (Aix galericulata) were chosen as a study species because, like many species of waterfowl, they are widely kept in both private institutions and zoos, yet little research has been conducted on their core needs in captivity. A free-living population of naturalised Mandarin Ducks living in Richmond Park was used for this research. Data on state behaviours (resting, swimming, foraging, perching, preening, and vigilance) were collected five days a week (08:00–18:00) from the 26 March to 26 May 2021. Secondly, temporal, seasonal, environmental, and animal-centric factors (e.g., Sex) were recorded to assess any impact on the Mandarin’s time-activity budget. Lastly, a comparison between free-living anmd captive activity was conducted (via the literature) to evaluate whether captive behaviours differ to how they are expressed in the wild. Results showed that free-living Mandarins predominantly rested (19.88% ± 28.97), swam (19.57% ± 19.43) and foraged (19.47% ± 25.82), with variations in activity related to factors such as vegetation cover and pond size. Results also showed differences between the time-budgets of free-living and captive Mandarins, suggesting that captive birds may not always have the opportunity to express species-typical behaviours. This research indicated that study of natural behaviours performed in the wild may help to evaluate “normal” behaviour patterns of zoo-housed individuals and provide evidence for environmental and husbandry alterations that can promote good welfare. However, any potential impact on the activity patterns of free-living species due to human interactions should be considered when assessing deviations between the behaviour of wild and captive individuals.

Space, time, and context drive anticipatory behavior: Considerations for understanding the behavior of animals in human care

Animal-based measures reflecting the welfare state of individuals are critical for ensuring the well-being of animals under human care. Anticipatory behavior is one potential animal-based measure that has gained traction in recent years, as it is theorized to relate to animals' reward sensitivity. It is of particular interest as an assessment for animals living under human care, as the predictability of the captive environment lends itself to the development of this class of behaviors. Animals are likely to exhibit anticipation in locations related to the anticipated event, often in temporally predictable time frames, and before specific contexts they experience in their day-to-day management. In this sense and under certain circumstances, anticipatory behaviors are likely to drive observed behavioral or space use patterns of animals under human care. Drawing conclusions from such data without identifying anticipation may result in misleading conclusions. Here we discuss how space, time, and context are related to patterns of anticipatory behaviors in animals under human care, how unidentified anticipation may alter conclusions regarding animal behavior or welfare under certain circumstances.

Members of the Pod: Do Marine Mammal Trainers Perceive a Bond with the Animals They Care For?

Animals under human care interact with their caretakers, potentially resulting in human–animal bonds (HABs), which can enhance wellbeing for both. Previous research has suggested that keepers perceive bonds with their animals, but investigation of a different zoo role working with one species has not yet been completed. Here, we investigate the animal trainers’ perception of HABs with captive bottlenose dolphins (Tursiops truncatus). A modified Lexington Attachment to Pets Scale (LAPS) was used to measure the strength of perceived HABs between trainers and both dolphins and companion animals in their care. LAPS questionnaires were completed by 128 trainers from 35 different collections worldwide. Most respondents perceived themselves to have a bond with a dolphin, although LAPS scores for attachment to dolphins (DA) were significantly lower than for companion animals (CA). Female LAPS scores were significantly higher than males for both DA and CA. Multiple regression demonstrated that the facility and trainer gender were significant predictors of CA. LAPS scores for trainers were comparable to those for zoo animals, which reflects a strong attachment to the dolphins they work with. However, this attachment was not as strong as for their companion animals, and was influenced by the collection they worked for.

Zoo Closure Does Not Affect Behavior and Activity Patterns of Palawan Binturong (Arctictis binturong whitei)

Exploring the interaction between humans and animals has become increasingly important in the evaluation of well-being for species housed in zoos and aquaria. The COVID-19 pandemic saw the global closure of zoos and aquaria to visitors. Chester Zoo, U.K., was no exception, with the charity shutting its doors for the longest period in its 90-year history. Whilst access to site was strictly limited to essential animal care staff, recent investment in networked infrared CCTV camera systems allowed some species to be monitored remotely during this extraordinary period of zoo closure. Here, we used this equipment to investigate whether zoo closure influenced activity patterns and behavior of two adult Palawan binturong, Arctictis binturong whitei. The cameras facilitated behavioral monitoring over 24 h enabling the collection of a full activity budget, which revealed a natural crepuscular activity pattern. Overall, visitor presence was found to have a neutral effect on this species, with no significant difference observed in time spent engaging in den use, vigilance or travel behaviors during zoo open and zoo closed conditions. A neutral visitor effect was found when evaluating behavior over a 24 h period and during hours which the zoo would normally be open to visitors (10:00–16:30). This research presents new information on this elusive and understudied species in captivity, and promotes investment in monitoring equipment which enables more comprehensive behavioral sampling than traditional visitor-effect methods.

Comparing Space Use and Fecal Glucocorticoid Concentrations during and after the COVID-19 Closure to Investigate Visitor Effects in Multiple Species

We used the COVID-19 pandemic closure at the Saint Louis Zoo to examine visitor effects on space use and glucocorticoid levels in banteng, grizzly bears, polar bears, and western lowland gorillas. The study was divided into four six-week phases: closure in spring 2020, reopening in summer 2020, fall 2020, and spring 2021 as a seasonal comparison. Space use data were collected using video, and fecal samples were assayed for glucocorticoids. Generalized linear models were used to examine differences in zone occupancy and glucocorticoids between phases. The banteng spent more time near visitors, and glucocorticoids were only temporarily elevated in two of five animals when visitors returned. The grizzly bears spent more time in their habitat than in the den, and the polar bear spent more time near viewing areas after visitors returned. Glucocorticoids did not differ significantly between the closure and reopening for any bears. The gorillas spent less time close to visitors immediately after reopening but this effect waned by fall; glucocorticoid data were not available. Overall, based on space use and glucocorticoid levels, we suggest visitor effects on the gorillas are neutral, on the grizzly bears are neutral or positive, and are positive on the banteng and polar bear.

Behaviour of Zoo-Housed Red Pandas (Ailurus fulgens): A Case-Study Testing the Behavioural Variety Index

The red panda is listed as “endangered” in the IUCN Red List of Threatened Species, due to the rapid population decline. Improving our knowledge on the red panda biology and ethology is necessary to enhance its husbandry and breeding in zoos. Behavioural variety, intended as the presence of a wide array of species-specific behaviour, has been considered a positive welfare index in zoo-housed animals. The aim of this study was to describe the behaviour of two pairs of zoo-housed red pandas, one of them with an offspring, and to investigate the behavioural variability using the Behavioural Variety Index (BVI). Behavioural data from two zoo-living male–female pairs were collected. A continuous focal animal sampling method was used to collect individual and social behaviours of the two pairs. Forty-eight 30 min sessions per subject were carried out. For the BVI, a list of species-specific behaviours previously reported in the red panda was prepared and compared with the behavioural repertoire of the subjects of the study. First, species-specific behaviours were recorded, and no abnormal behaviour was reported. The percentages of time spent on different activities (e.g., routine behaviours, exploratory/territorial behaviours, consumption behaviours, locomotive behaviours, social behaviours, maternal behaviours) were similar to time budgets reported in the red panda, with routine behaviours (resting, comfort and vigilance) being the most performed in both pairs. Moreover, the BVI suggested that each red panda performed on average 73% of the behaviours described in previous literature on this species. In conclusion, studying the behavioural variety of red pandas in zoos can be a useful tool for assessing their welfare as well as improving our knowledge on the behavioural repertoire of a species that is difficult to observe in the wild.

Bird Welfare in Zoos and Aquariums: General Insights across Industries

Animal welfare is a priority across accredited zoological institutions; however, historically, research has been prioritized for mammals. Bird-focused studies accounted for less than 10% of welfare research in zoos and aquariums over the last ten years. Due to the lack of scientific publications on bird welfare, zoo scientists and animal practitioners can look to other industries such as agriculture, laboratories, and companion animal research for insight. This qualitative review highlights findings across industries to inform animal care staff and scientists on the welfare needs of birds within zoos and aquariums. Specifically, the review includes an overview of research on different topics and a summary of key findings across nine resources that affect bird welfare. We also highlight areas where additional research is necessary. Future welfare research in zoos and aquariums should prioritize studies that consider a diversity of bird species across topics and work to identify animal-based measures with empirical evidence. Moving forward, research from other industries can help develop innovative research on bird welfare within zoos and aquariums.

Do Birds of a Feather Always Flock Together? Assessing Differences in Group and Individual Zoo Enclosure Usage by Comparing Commonly Available Methods

Data on zoo enclosure usage provide meaningful evaluation of husbandry and welfare but for social species, group-level data may not capture individual occupancy preferences. Determining zone occupancy using group data may give an inaccurate assessment of enclosure suitability for each individual. We compared three formulae (traditional and modified Spread of Participation Index and Electivity Index) to determine how estimations of space usage compare between individuals and their group overall. Two flamingo flocks at two zoos were sampled with enclosures separated into discrete zones. Counts of where each bird in the flock was located at each minute of sampling were compared against the number of minutes that randomly selected individual flamingos spent in each zone. Overall, there was little difference in preferred zone occupancy when flock data were compared to individual data. Group data suggested that flamingos were more consistent in their enclosure usage, with individual data showing wider overall usage of enclosures. Individual Electivity Index (EI) values suggested zone underuse whereas group EI suggested zone overuse. As a proxy for welfare measurement, we recommend both group-level and individual monitoring of space use to provide a complete picture of how individuals within a social group occupy their space and choose where to be.

Investigating the Behavior and Personality Structure of the Aldabra Tortoise during Human Interactions and Training Events

Simple Summary

There are many studies that suggest that a range of animal species have personalities, and that animals can benefit from interactions with their human caregivers. However, many of these previous studies have focused only on mammals, with fewer studies focusing on reptiles. Research was undertaken at the Faunistic Park Le Cornelle, Italy, to investigate the effects of approach tests and food interaction events on 5 male and 5 female Aldabra tortoises’ (Aldrabrachelys gigantea) behavior. There were differences in behavior between tortoises, and in response to different types of events. The tortoises also responded differently to their own keepers, vets, or unfamiliar people. The personality of the tortoises were also quantified using principal component analysis. Overall, the study revealed that individuals acted significantly differently to one another, and that while females initially appeared to display a greater number of shy behaviors, this was not consistent across the group. PCA revealed two personality dimensions in the tortoises, boldness and avoidance. Overall, the study revealed that the tortoises possessed personalities that were independent of sex or scenario. The study also revealed that many tortoises chose to interact with their keepers during training and approach tests: this suggests that human-tortoise interactions may have some enrichment value. Future research could quantify tortoise personality in other scenarios, such as in social interactions with other tortoises.

Abstract

Human–animal interaction (HAI) can be valuable for captive animals, and many zoo-housed species benefit from interactions with their keepers. There is also an increasing body of evidence that some animal species possess personalities that are temporally consistent. However, the majority of zoo research, particularly on personality and HAI, traditionally has focused on mammals, and there are comparatively fewer studies on reptiles. Research was undertaken at the Faunistic Park Le Cornelle, Italy, to investigate the effects of approach tests and food interaction events on 5 male and 5 female Aldabra tortoise (Aldrabrachelys gigantea) behavior. During human–tortoise interactions, continuous focal sampling of behavior took place. The behavioral differences between individual tortoises, interaction type (approach or training) and person involved in the interaction (keeper, vet, or observer) were analysed using general linear mixed-effects models. The personality components of the tortoises were also quantified using principal component analysis. Overall, the study revealed that individuals acted significantly differently to one another, and that while females initially appeared to display a greater number of shy behaviors, this was not consistent across the group. PCA revealed two personality dimensions in the tortoises: boldness and avoidance. Overall, the study revealed that the tortoises possessed personalities that were independent of sex or scenario. The study also revealed that many tortoises chose to interact with their keepers during training and approach tests: this suggests that human–tortoise interactions may have some enrichment value. Future research could quantify tortoise personality in other scenarios such as in social interactions with other tortoises.

Exploring the Effect of the COVID-19 Zoo Closure Period on Flamingo Behaviour and Enclosure Use at Two Institutions

Visitors can influence the behaviour of zoo animals through their auditory and visual presence, with mixed findings of negative, neutral, and positive effects on welfare. This study opportunistically utilised the UK-wide COVID-19 period of zoo closure to investigate the activity and enclosure usage of Greater (Phoenicopterus roseus) and Chilean (P. chilensis) Flamingos housed at two zoos. Flamingo behaviour at both sites was observed during the last week of a three-month closure period and the immediate reopening of the zoos. Photographic data were collected at three timepoints during each observation day. Negative binomial GLMMs compared the behaviour observed during zoo closure to the behaviour observed during zoo reopening, whilst accounting for climatic variables and time of day. Spearman’s correlation identified relationships between behaviour with the number of visitors and weather. Greater Flamingos were not influenced by the reintroduction of visitors to the zoo setting. Chilean Flamingos showed an increase in inactivity and decrease in movement and feeding when the zoo reopened. These possible behavioural responses are better explained by the influence of temperature on the behaviour of Chilean Flamingos and by the correlation between temperature and visitor number, rather than a direct consequence of visitor presence. This research details the multifactorial nature of any potential anthropogenic effects on zoo animal behaviour and highlights the importance of considering environmental variables alongside the measurement of visitor presence or absence.

Should Zoo Food Be Chopped for Captive Turacos?

It is common practice for keepers in zoological collections to provide animals in their care with food that is chopped into small pieces. Anecdotally, it has been suggested that chopped food reduces wastage and reduces aggression from group-housed animals. However, there is limited empirical evidence to support these suggestions. To investigate the effects of food condition (chopped or whole food), a study was undertaken on White-cheeked Turacos (Tauraco leucotis) and Fischer’s Turacos (Tauraco fischeri) at two zoological collections in the United Kingdom. This study investigated the effect of food condition on turaco behaviour, the amount of food eaten, and also the amount of time that keepers required to prepare the diet. There was no significant impact on the amount of food eaten as a result of providing whole food. For Fischer’s Turacos, the whole-food condition significantly increased the prevalence of feeding and foraging behaviour, whilst significantly reducing preening. For White-cheeked Turacos, only feeding and foraging was affected by food condition: no other behaviours were significantly affected by chopped or whole food. Keepers on average saved 151 s per meal when preparing whole-food diets. Overall, this study suggests that changing food presentation from chopped to whole has a limited impact on food intake and behaviour. Providing whole-food items may also save valuable keeper time. Future studies should investigate the impact of feeding whole-food items to a wider range of zoo-housed species.

Investigating the Effect of Enrichment on the Behavior of Zoo-Housed Southern Ground Hornbills

Enrichment is essential for the welfare of many zoo-housed animals, yet the value of enrichment is not well understood for all taxa. As an intelligent, long-lived species, the southern ground hornbill (Bucorvus leadbeateri) is a good model for enrichment research. A pair of southern ground hornbills, housed at Beale Wildlife Park and Gardens, were observed during study periods in 2014, 2018, and 2019. Three types of enrichment were provided for the birds; these enrichment types were developed based on information on the habits of the species as found in natural history papers. The enrichment types consisted of a pile of twigs, small animal carcasses, and plastic mirrors. Overall, the carcass feeds and the mirrors resulted in the greatest changes in behavior, with hornbills engaging in long periods of food manipulation with carcasses. For the mirror condition, hornbills spent time stalking around and pecking at mirrors, similar to the ‘window smashing’ behavior seen in wild hornbills. Overall, the research suggests that not only can enrichment modify the behavior of southern ground hornbills, but non-nutritional enrichment may be equally valuable to the animals. Natural history papers may have some value in inspiring novel enrichment items for zoo-housed animals.

Conducting Behavioural Research in the Zoo: A Guide to Ten Important Methods, Concepts and Theories

Behavioural research in zoos is commonplace and is used in the diagnosis and treatment of potential husbandry and management challenges. Robust methods that allow valid data collection and analysis constitute an evidence-based approach to animal care. Understanding behaviour is essential to improving animal management, and behavioural research is therefore popular, with a wide choice of behavioural methodologies and theories available. This review outlines ten methodological approaches, concepts or theories essential to zoo science that are based around behavioural observation. This list is not exhaustive but aims to define and describe key areas of consideration when planning and implementing a zoo-based behavioural project. We discuss the application of well-established methods (the construction of ethograms, use of time–activity patterns and measurement of space/enclosure use) as well as evaluating newer or less-widely applied analytical techniques, such as behavioural diversity indices, social networks analysis and Qualitative Behavioural Assessment. We also consider the importance of fundamental research methods, the application of pure science to understand and interpret zoo animal behaviour (with a review of a Tinbergian approach) and consideration of meta-analyses. The integration of observational techniques into experiments that aim to identify the cause and effect of behavioural performance is then explored, and we examine the assimilation of behavioural methods used in studies of environmental enrichment. By systematically studying animal behaviour, we can attempt to understand the welfare of individual animals in captivity, and here we present an example of our reviewed approaches to this area of zoo science. Combining multiple methodologies can lead to a greater understanding of behaviour and welfare, creating robust research, progressing husbandry and advancing conservation strategies. Collaborations between zoological collections and academic researchers (e.g., in Higher Education Institutions) can further refine and enhance the validity of research and husbandry practice alike.

Bold Frogs or Shy Toads? How Did the COVID-19 Closure of Zoological Organisations Affect Amphibian Activity?

Simple Summary

The visitor effect describes how zoo animals respond to the presence of visitors to their enclosures in a positive, negative or neutral manner. The period of enforced closure of zoos due to the COVID-19 pandemic in March 2020 (and subsequent reopening later that year) allowed for the effect of visitor presence to be evaluated on several species of amphibian. Results have shown that amphibian visibility (i.e., likelihood to be on show in their enclosure) is potentially influenced by the presence of people, and therefore, enclosure layout, collection planning and amphibian husbandry should consider how to minimize any negative influences of the viewing public.

Abstract

Amphibians are an understudied group in the zoo-focussed literature. Whilst commonly housed in specialist exhibits and of real conservation value due to the global extinction crisis, amphibian welfare is not often investigated empirically in zoo settings. The limited research that is available suggests that enclosure design (structure, planting and naturalistic theming) has a positive impact on the time that amphibians will be on show to visitors. However, the categorisation of any “visitor effect” (i.e., influences of visitor presence on amphibian activity and time on display) is hard to find. The COVID-19 pandemic forced the closure of zoological organisations in the UK for several months from March 2020, with gradual re-openings from the summer into autumn and winter. This event provided a unique opportunity to study the effect of the lack of visitors, the presence of essential zoo staff only, the wider return of organisational staff, and then the return of visitors over a prolonged period. This project at WWT Slimbridge Wetlands Centre assessed the number of individuals of six species of amphibian—common toad (Bufo bufo), common frog (Rana temporaria), smooth newt (Lissotriton vulgaris), pool frog (Pelophylax lessonae), golden mantella (Mantella aurantiaca) and golden poison dart frog (Phyllobates terribilis)—visible to observers under different conditions. All amphibians were housed in a purpose-built indoor exhibit of individual enclosures and were recorded when visible (as a proportion of the total population of the enclosure) during closure, the return of extra centre staff and visitor periods. The results showed species-specific differences in visibility, with some species of amphibian being more likely to be on view when the presence of people at their enclosure was less likely or in smaller numbers. Such differences are likely related to the specific camouflage or anti-predation tactics in these focal species. Further study to quantify amphibian sensitivity to, and perception of, environmental change caused by public presence (e.g., light levels and sound) would be useful welfare-themed research extensions. Our results can help inform husbandry, collection planning and amphibian enclosure design to reduce any noticeable visitor effects, and provide a useful benchmark for further, more complex, welfare assessment measures.

Visitor presence and a changing soundscape, alongside environmental parameters, can predict enclosure usage in captive flamingos

The sound environment of a zoo animal is a complex milieu of animal and human-generated sounds; coming from the species itself, other species, visitors, keepers and other zoo-users. Research determining how different components of the sound environment affect animal behaviour is surprisingly lacking but could have real-world impacts for animal welfare and zoo enclosure design. The current study investigated the effects of the sound environment on two flocks of flamingos housed in open-air enclosures at British zoos. Measures of how each flock used its enclosure (as a response variable) and environmental variables (Inband Power and Peak Frequency were recorded as characteristics of the sound environment, as well as temperature, humidity and cloud cover, and finally visitor presence-all as potential predictor variables) were made over a 2-month period. Assessment of space use by zoo animals is often used as a measure of the appropriateness of an exhibit and to understand welfare. Given that flamingo activity is influenced by weather and that the sound environment of the zoo is likely to be influenced by the number and the presence of visitors, it was assumed that these predictor variables would influence where the flamingos were located at different times of the day. As expected, there was a complicated relationship between enclosure use and Inband Power (average spectral density, a measure of sound energy) in both flocks; visitors generated salient sound but other visitor characteristics such as their physical presence may have impacted the movement of the birds around their enclosures. Results show a complex picture where environmental conditions influence flamingo enclosure usage as well as visitor presence and sounds around/in the enclosure. Findings are not consistent between the two flocks, with one flock demonstrating distinct temporal change to enclosure zone occupancy and the other responsive to humidity and cloud cover variation. We believe enclosure use can provide a valuable indication of how birds react to their soundscape; however, our findings suggest more work is needed to unpick the components of captive sound environments, and their relative effects on how animals use their space.