We previously reported that African (Loxodonta africana) and Asian (Elephas maximus) female elephants in European zoos have shorter adult lifespans than protected conspecifics in range countries. This effect was the cause of greatest concern in Asian elephants, and risk factors within this species included being zoo-born, transferred between zoos, and possibly removed early from the mother. Here, we investigate these risk factors further; assess fecundity and sustainability in European zoos; and propose testable hypotheses as to the causes of these animals’ problems. Although imported wild-born Asian elephants live longer than zoo-born conspecifics, being imported when juvenile or adult appears no more protective than being imported in infancy, suggesting that the benefits of being wild- rather than zoo-born are conferred early in life. Zoo-born Asian neonates are significantly heavier than those born to working animals in range countries, with a possible tendency to be fatter. In zoos, African elephants have tended to be removed from their mothers at older ages than young Asians, and were also transferred between zoos significantly less often: factors that could possibly underlie this species’ lower calf losses and improving adult survivorship in Europe. Both species have low fecundity in European zoos compared to in situ populations, and are not self-sustaining, declining at approximately 10% per annum if reliant on captive-bred females under historically prevailing conditions. Data from other species suggest that stress and/or obesity are parsimonious explanations for the suite of problems seen. We recommend specific screens for testing these hypotheses, and for potentially identifying vulnerable individuals within the extant zoo populations.

Scientific studies of human-animal interactions (HAIs) and how these develop into human-animal relationships (HARs) now represent some of the most significant contributions to animal welfare science. However, due to the current definition of HAR, studies have only been able to measure HAIs and infer its impact on HARs and animal welfare. Here, we redefine HARs as a series of repeated HAIs between two individuals known to each other, the nature of which is influenced by their historical HAIs and where consideration to the content, quality and the pattern of the interactions is also vital. With a new definition, it is now feasible to empirically measure HARs, however, first, it is important to evaluate current methods utilised in animal industries to allow standardisation across HAR research in zoos. Here, we review the current methods that have been used to assess HAIs in animals and determine their overall suitability for measuring HARs and their use in a zoo environment. Literature searches were conducted using the search terms ‘human-animal’ AND ‘interaction’, ‘human-animal’ AND ‘relationship’, ‘human-animal’ AND ‘bond’. Subsequently, ‘zoo’, ‘companion’, ‘agriculture’, ‘laboratory’ and ‘wild’ were added to each combination yielding five potential methods to evaluate. These methods were assessed according to a panel of indicators including reliability, robustness, practical application and feasibility for use in a zoo environment. Results indicated that the methods utilising ‘latency’, ‘qualitative behaviour assessment’ and the ‘voluntary approach test’ were potentially viable to assess HARs in a zoo environment and could subsequently contribute to the assessment of welfare implications of these HARs for the animals involved. These methods now require empirical testing and comparisons within a zoo environment.

To be able to assess animal welfare the researcher must presuppose a number of background assumptions that cannot be tested by means of ordinary empirical data collection. In order to substantiate these assumptions two sorts of inferences have to be relied upon, which the authors designate by the terms ‘analogies’ and ‘homologies’. Analogies are evaluative, philosophical reflections by means of which it is made clear what provisions or states constitute the welfare of humans and other animals. By means of analogies it may, for example be argued that animal welfare consists of subjective experiences such as pain, boredom, pleasure and expectation. Also by means of analogies the relative ‘weight’ of these states can be decided. Homologies are part of theoretical science. They serve to clarify how the relevant experiences are linked to measurable anatomical, physiological and behavioural parameters.

An account is given of the steps which have to be taken to give a full answer to a question concerning the welfare of animals. In the account only farm animals are mentioned, but the same steps, of course, also have to be taken to answer questions concerning the welfare of other kinds of animals be they companion, laboratory, zoo or wild. Eight steps are described, and it is argued that both analogies and homologies are needed at very fundamental levels. Therefore, if animal welfare science is to provide relevant, rational and reliable answers to questions concerning animal welfare, it must be an interdisciplinary inquiry involving philosophical reflections and theoretical biology.

Foraging ecology and food patch studies are commonly used to elucidate the environmental perceptions of wild, free-ranging animals. Their application to captive animals, however, especially those in zoos, is still in its infancy. To illustrate some specific applications of zoo foraging ecology, we provide a study that evaluated: (i) whether patch use and giving-up densities (GUDs) can reveal areas of preference within an exhibit for zoo species; (ii) if food patches provide an effective form of behavioural enrichment; and (iii) if visitor interest and behaviour is affected by food patch presence. A combination of behavioural observations, and experimental food patches and giving-up densities were used to address these objectives in Parma wallabies (Macropus parma) and Patagonian cavies (Dolichotis patagonum) at Lincoln Park Zoo, Chicago, Illinois USA. GUDs revealed distinct areas of preference and aversion within the exhibit for cavies, but not so for the wallabies. For both species, presence of food patches increased foraging behaviours, decreased inactive behaviours, and increased within-exhibit movement, demonstrating that food patches serve as an effective behavioural enrichment technique. The use of food patches also revealed striking differences between individuals, particularly for the pair of cavies. There were encouraging trends toward increased visitor number and stay-time when food patches were present in each exhibit, but the effect was not statistically significant. These results suggest that utilising patch use, GUDs, and foraging theory in zoo populations may enhance animal welfare, and can inform improvements to exhibit design directly from the animal's perspective. We conclude with a broader discussion of zoo foraging ecology as an emerging field, with suggestions for future avenues of research.

Modern zoos are increasingly successful in maintaining and breeding exotic species. Many of the animals bred in captivity cannot be housed in their natal zoo nor in other recognized zoos in the region. These ‘surplus ‘ animals create a problem as zoos only have limited space at their disposal. The options open in this situation are to avoid the problem by preventing the animals from breeding (sterilization or contraception) or to dispose of the surplus animals (euthanasia; or transfer either to institutions not recognized by any national zoo federation or to a zoo outside the region, possibly using the services of an animal dealer). The pros and cons of all these options are evaluated in terms of practicality, welfare and ethics. In many cases, the judicious use of a combination of contraception and euthanasia would seem the most acceptable choice from an animal welfare point of view. Nevertheless, it is believed that considerably more research is needed into the methods and welfare aspects of contraception and sterilization.

The influence of an environmental enrichment feeding device (puzzle feeder), on activity and behaviour patterns of captive orang-utans, gorillas and chimpanzees was studied at London Zoo. General activity levels and behaviours directed towards the feeder increased for all species when the feeder was filled with food Chimpanzees used the feeder significantly more (18% of observation periods) than either gorillas (10%) or orang-utans (9.4%). There was considerable individual variation of puzzle use by individuals within each group and time of day also affected use. In some instances abnormal behaviours were reduced. These results are discussed in relation to the management of captive great apes and it is suggested that the use of puzzle feeders can improve the welfare of these animals.

Many captive Asian elephants (Elephas maximus) in Thailand participate in the tourism industry at attractions known as ‘elephant camps.’ There has been significant criticism of low welfare venues, where the elephants may experience injuries, poor nutrition, unnatural social environments and aversive handling. Despite increasing concern for animal welfare, the general public often have difficulty identifying the welfare issues affecting captive animals. The aim of this study was to investigate participants’ willingness to support an elephant attraction and their perceived emotional value from the experience, based on the affective state of the captive elephant and their level of contact with it. Participants (n = 590) from the United States were randomly assigned to one of four vignettes (using a 2 × 2 experimental design) that described an elephant attraction, varying the affective state of the elephant (feels excellent, feels terrible) and the level of contact they could have with the elephant (low, high). A mixed methods approach was used, where participants provided answers to Likert-type questions, followed by an open-ended response. Participants showed greater willingness to support the elephant attraction and greater perceived emotional value from the experience when the elephant felt excellent, as opposed to when the elephant felt terrible. There were no significant differences between low and high contact for the measures included in this study. Qualitative responses varied greatly, with participants making many assumptions about the elephant and the attraction, revealing potential misconceptions that they had regarding the welfare of captive elephants. This research may be used to encourage a shift in tourism preferences to venues that reflect positive elephant welfare.

Many captive giraffes perform oral stereotypies, in particular tongue-playing, licking of objects (including conspecifics) and vacuum chewing. Typically, the diet of these large ruminants in captivity consists mostly of food concentrates, which are consumed rapidly and do not provide stimulation for their long, prehensile tongues. In the wild, browsing requires extensive use of this organ but in captivity material upon which to browse is limited. Consequently, vacuum activities, such as mock leaf-feeding behaviour, and stereotypies may develop. Rumination is also a major component of a giraffe's behavioural repertoire. It is essential for proper digestion, but may also be connected with non-REM sleep. Inadequate opportunities for rumination may also contribute to the development of oral stereotypies. In this study of captive giraffes, we examined the effect of increasing dietary fibre on the time spent ruminating and feeding and the extent to which oral stereotypies were performed. Two giraffes of different age, sex and sub-species were studied at Paignton Zoo Environmental Park. Dietary fibre was increased by the addition of coarse meadow hay to their existing diet. Following the addition of hay, time spent feeding did not change significantly but there was a significant increase in the time spent ruminating and a significant reduction in time spent performing oral stereotypies by both giraffes, suggesting that oral stereotypies may be connected with rumination rather than feeding. Stereotypic behaviour is generally accepted to be an indicator of sub-optimal welfare. Thus, the reduction in this behaviour by the simple addition of coarse fibre to the diet can be interpreted as enhancing the welfare of these animals.

In modern zoos, training should be an integral component of the animal care and management. The benefits of training include the opportunity for positive interactions with caretakers. This study was carried out with a group of vervet monkeys (Chlorocebus aethiops) housed at the Garda Zoological Park, Italy. Using focal animal sampling, we observed the behaviour performed by all group members from December 2007 to August 2008. The group took part in a training programme to be isolated in a familiar area before the subjects were included in a cognitive study. We collected behavioural data during a pre-training period to assess the social behaviour of the colony and during the training period to investigate the effects of the training programme on the behaviour of individuals. Additionally, a second phase of the study was conducted and training sessions with individual monkeys were video-recorded to determine the behaviour of animals during each training session and to thus confirm that they were suitable for participating in the procedure. Our results suggest that the training programme enriched the daily routine of these captive primates by increasing affiliative behaviours while decreasing agonistic behaviours. Furthermore, there was behavioural response variability among the individuals under the training procedure. However, all the individuals were trained to calmly enter a familiar area and be isolated from other members of the group. In conclusion, our findings highlight the importance of using positive reinforcement training to reduce the tension directly associated with potentially stressful procedures by allowing primates to participate voluntarily in these procedures. In addition, the training was found to be an enrichment tool for vervet monkeys.

Procedures that increase foraging and exploratory behaviours are generally accepted as effective at improving welfare and reducing stereotypies in captive animals. To determine the effect of food and toy enrichment on the behaviour and hormonal levels of maned wolves (Chrysocyon brachyurus), 11 wolves were submitted to a baseline-enrichment-baseline schedule with four enrichment conditions: food scattering, toy presentation, edible toy presentation, and a combination of food and toy conditions. Behaviour and glucocorticoid metabolite concentrations (GCM) were assessed throughout the experiment. Our hypotheses were that enrichment procedures would lead to an increase in activity in the short and long term, a decrease in pacing, and a reduction in GCM concentrations. We also hypothesised that the concentrations of GCM would show a correlation with behaviour. Enrichment conditions increased immediate locomotion but did not produce long-term changes of activity nor reduced pacing. The procedures had a clear effect on individual behaviour and induced, under food enrichment conditions, an increased interest in food. Enrichment did not lead to decreased GCM concentration in the group as a whole, but there was a tendency for male and female animals to differ in hormonal reactions to environmental change. A positive correlation between GCM concentrations and pacing behaviour and a negative correlation between GCM concentrations and social behaviour were found. Results suggest that food scattering as an enrichment procedure may be used with maned wolves to enhance welfare, whilst also revealing the importance of taking individual and gender differences into account when planning enrichment techniques.

Societal concern for animals under human care has influenced our approaches to advance animal welfare in a variety of contexts. The Animal Programs Department at the Columbus Zoo and Aquarium sought partnership with the Center for Human-Animal Interactions Research & Education (CHAIRE) at The Ohio State University to develop a holistic welfare approach for the animals within their department using a focal species, the cheetah (Acinonyx jubatus). A one-year project using the Five Domains Animal Welfare Model collected data over six 60-day periods to evaluate long-term cortisol production and behavioural observations of cheetahs under changing environmental factors. Species and individual histories were incorporated with behavioural observations and hair cortisol production, giving a holistic view of welfare. Cortisol and behavioural data were analysed using linear models to compare cheetahs at population and individual levels. Participation in a cheetah run activity, housing occupancy, and 60-day period were found to influence all behaviours within the population and stereotypic behaviour also differed within individual cheetahs. No differences in hair cortisol concentrations were found for the group, but further analysis revealed differences within individuals throughout the study. No correlation of stereotypic behaviour and cortisol levels were found. This study created a welfare assessment protocol that can be used within zoological institutes and was the first to measure cortisol concentrations in hair in cheetahs.

The measurement of salivary cortisol allows non-invasive assessment of welfare in captive animals. We utilised this technique to test the effect of zoo opening on six Asian elephants and two Indian rhinoceros at the Terra Natura Zoological Park, Alicante, Spain, during pre-opening, opening and post-opening periods. Salivary cortisol concentrations were found to be significantly higher during the opening period than during pre- and post-opening periods for both species. This method could prove a useful tool in monitoring the success of decisions taken to improve the welfare of captive animals.

The decision to perform euthanasia in geriatric zoo mammals is usually a highly complex procedure involving ethical, medical, emotional and sometimes political factors. However, subsequent necropsies show that the pathological changes of organs and/or the musculoskeletal system are often already advanced. Therefore, we hypothesise that euthanasia is often delayed to the detriment of the animal's welfare. The purpose of this study was to facilitate and establish an initial, objective, decision-making framework for the euthanasia of geriatric zoo mammals. A scoring-system to assess the physical condition and quality of life in ageing zoo mammals is presented, based on retrospective and prospective investigation of 70 geriatric zoo mammals in five European zoos. Medical records and necropsy reports were studied in retrospective cases. Symptoms were monitored and recorded in prospective cases. Radiographic investigations under general anesthesia or at necropsy were performed additionally. A significant association between symptoms and pathological findings revealed that 36.9% (n = 24/65) of examined animals (n = 41/65) had pathological alterations to the musculoskeletal system and 26.2% (n = 17/65) suffered from neoplasia. Based on the individual reports, 28 veterinarians from different fields of veterinary medicine concluded that these animals had mild to severe pain, discomfort and a significantly reduced quality of life, thus strongly reducing welfare. The proposed scoring system includes all of these factors and offers a simple and reliable tool to support decision-making for euthanasia in geriatric zoo mammals.

The outbreak of coronavirus disease (COVID-19) represents a major public health challenge and a serious threat to sustainable social development. A consideration of animal welfare is clearly justified, given the potential contribution of animals to the spread of the disease. The present study, therefore, sought to investigate the concern the Chinese people have for animal welfare (PCAW) and how their ‘ethical ideology’ (idealism and relativism) determines PCAW after COVID-19, through comparison with the same study, carried out in China in 2015. Our results demonstrated a significant improvement in Chinese PCAW after COVID-19. The adverse impact of COVID-19 may have resulted in a lowered idealism score and this decreased score served to neutralise significant correlations between idealism and PCAW, compared to the 2015 results. The global pandemic did not increase people's relativism score and a significant correlation was found between relativism and PCAW. Gender, age, educational level, public perception of animals after COVID-19, zoo and aquarium visiting were all shown to be predictor variables for PCAW. This study is one of the first to investigate Chinese PCAW after COVID-19 and can therefore provide knowledge that will potentially increase Chinese PCAW.

The ability to monitor the welfare of animal collections in zoological institutions is critical to the mission of these facilities. Historically, zoos have utilised negative indicators of welfare, such as stereotypic behaviour to examine and monitor collection animals. However, absence of stereotypic behaviour or negative indicators of welfare does not indicate that an animal is thriving. The goal of the current study was to continue efforts to validate behavioural diversity as an indicator of welfare using cheetah (Acinonyx jubatus) as a model species. Behavioural and faecal glucocorticoid metabolite data were collected on 18 cheetah at the San Diego Zoo Safari Park over a period of three months to explore the relationship between behavioural diversity and adrenal hormones related to the stress response. Results suggest that behavioural diversity can be utilised as an indicator of animal welfare to monitor animal collections within zoological facilities. However, additional research with other species should be conducted to better understand behavioural diversity as a positive indicator of animal welfare. We hope this manuscript will increase discussion surrounding behavioural diversity as well as increase efforts to validate it as an indicator of welfare.

This study explored the effect of auditory stimulation on the behaviour and welfare of four zoo-housed, female Asian elephants (Elephas maximus). All animals were exposed, in an ABA design, to two conditions of auditory stimulation: a ‘control’ (no auditory stimulation), and an ‘experimental’ condition, during which the animals were presented with a commercially-available CD of classical music. Each condition lasted for five days, with an interim period of two days between each condition (Study 1). The elephants’ behaviour was recorded every minute for four hours a day for the full five days of each condition using instantaneous scan-sampling. The procedure was repeated four months later (Study 2), for a shorter period of time (one day per condition, again using an ABA design) to assess whether the results are generalisable. Analysis of both studies revealed that the elephants spent significantly less of their time stereotyping during the experimental conditions than the control. None of the other behaviours recorded were influenced significantly by auditory stimulation. Overall, the findings from this study suggest that auditory stimulation, in the form of classical music, may be a useful method of reducing stereotypic behaviour in zoo-housed Asian elephants, although more long-term work with a larger number of animals is needed before firm conclusions can be drawn.

The presence of human visitors has been shown to affect the behaviour of several different mammalian species in a number of different zoos, but the behavioural changes observed are not always consistent with a simple ‘stressful influence’ explanation. Data for non-primate species are too sparse to draw meaningful conclusions; but for primates, the evidence reviewed in this paper allows several hypotheses to be tested. Neither a social facilitation nor an audience attraction hypothesis can be generally supported by the available studies. However, these studies are consistent with a general stressful influence hypothesis, although the extent of this influence is itself affected by other variables, notably species and housing differences. There is some evidence that chronic exposure to human audiences may lessen this stressful influence in some species; and in certain circumstances (notably where some members of the public throw food) the effect of the audience is almost an enriching one.

The objective of this study was to determine if housing conditions, specifically pen size and soil enrichment, had an effect on faecal glucocorticoid concentrations in the endangered pygmy rabbit (Brachylagus idahoensis). The success of the captive breeding programme has been limited, so one hypothesis is that chronic stress due to sub-optimal housing conditions may be responsible for poor fecundity. Faecal glucocorticoid concentrations were assessed in 50 females housed among several pen types at two breeding facilities. The highest glucocorticoid concentrations were found in females housed in 0.37 m2 crates as compared to enclosures ranging from 0.96 to 75 m2 in size. Results also indicated that enrichment of enclosures with soil had a significant influence on adrenal activity, based on a reduction in glucocorticoid excretion for females moved from non-soil pens to those with soil. Last, a significant facility effect on glucocorticoid concentrations was observed, suggesting that factors other than housing influenced adrenal activity in these rabbits. In conclusion, based on measurements of faecal glucocorticoids, pygmy rabbits are best managed in enclosures that contain soil for digging burrows. Pen size had little effect on stress hormones, except for crates where limited space and/or absence of soil was associated with higher glucocorticoid concentrations. These results underline the importance of monitoring glucocorticoid concentrations in captive breeding programmes to identify optimal husbandry and management practices.

The present study examined the extent to which the introduction of three female Asian elephants (aged 3, 11, and 27 years) into a group of 1.4 (1 male, 4 female) elephants at Münster zoo, Germany, affects the behaviour and urinary Cortisol levels of the animals involved. At Münster, only the females were monitored — the bull was mainly kept separate. Behavioural observations were carried out before transfer and during the six-month period following transfer, and urine samples were collected regularly from each elephant during the whole observation period. All elephants showed behavioural changes to the process of introduction. The transferred animals increased their social behaviour after arrival in the foreign zoo. Two of them showed an increase in stereotypies and one a reduction in stereotypies. The elephants at Münster reacted with decreased frequencies of stereotypies and increased frequencies of social behaviour and manipulation/exploration behaviour. Six months after transfer, three of the four elephants at Münster and one of the three transferred elephants showed nearly the same behavioural activity pattern as before transfer. One female still showed elevated stereotypic behaviour. From the four elephants in which Cortisol measurements could be reliably performed (two of the transferred elephants and two elephants at Münster), only one individual at Münster responded to the process of introduction with a short-term elevation in urinary Cortisol levels. One elephant showed a negative correlation between locomotion and Cortisol levels and one a positive correlation between stereotypies and Cortisol levels. Taken together, the results suggest that transfer and introduction caused some stress responses in the elephants, but that stress was neither prolonged nor severe. Serious welfare problems may have been prevented through individual behavioural coping mechanisms and former experience with stressful situations.

Good animal welfare is crucial for the success of circuses and zoos. Epidemiological studies of animal welfare that investigate associations between animal-based measures (ABMs) and resource- and management-based measures are needed. However, due to the relatively low numbers of animals within each species kept at individual facilities, such investigations can be difficult to carry out. In this paper, we report the analysis of a multi-facility epidemiological study using data from all regulatory inspections of circus and zoo animals in Sweden for 2010 to 2014. Information from 42 inspections of 38 circuses, and 318 inspections of 179 zoos was analysed. For ABMs assessed during routine inspections of circuses (n = 14) and zoos (n = 61), 9.1 and 14.3% did not comply with requirements for general care of hooves/claws and coat, 10.0 and 8.6% for body condition, and 0 and 1.7% for animal cleanliness, respectively. In addition, the zoo checklist assessed whether animals were kept in appropriate groups, finding non-compliance in 17.0% of inspections. The most frequent non-compliant resource- and management-based measures at routine inspections of circuses were for space (41.7%) and exercise requirements (38.5%). For zoos, 29.4% did not comply with space followed by 28.8% for enrichment requirements. In multivariable logistic regression analyses, zoos that had inadequate or unsafe housing and space design, inadequate bedding, or failed to meet nutritional requirements, were more likely to be non-compliant with at least one ABM. The checklists should be improved to better assess welfare status by including more ABMs; benchmarking of risks and trends over time is also recommended.