Parrots (Psittaciformes) are widely kept in captivity, yet their welfare is under-researched in comparison to other captive species. This study aimed to determine key welfare issues affecting parrots through a modified Delphi approach. Twenty-eight welfare issues were first compiled via a preliminary literature review. Parrot welfare experts and sector professionals (n = 26) were then recruited to participate in an online survey to rank the identified welfare issues on a six-point scale according to severity, duration and prevalence of each issue. Participants could provide commentary on their ranking and propose additional welfare issues of concern. Items with a mean score of 4 or above progressed to a second survey, where participants (n = 14) indicated whether they agreed or disagreed with the current ranking of the welfare issue. Finally, two online workshops were held, where participants (n = 7) discussed the rankings from the second survey and sought to establish a consensus on the top ten welfare issues in each category and overall. Six of the seven final participants agreed with the final rankings, achieving a consensus rate of 86%. The top welfare issues overall were lack of owner knowledge and support; social isolation; housing; environmental opportunity to express behaviours; nutrition; development of normal behaviour; lack of a ‘life plan’ for birds; abnormal behaviours; lack of parrot-specific veterinary training; and insufficient application and enforcement of legislation. It is hoped that identification and recognition of these priority areas will be useful in directing future efforts in research, owner and veterinary education, and policy initiatives to improve parrot welfare.

The complexity experienced in early life can affect trait development of individuals, including sociability and fearfulness. The modern dairy calf’s rearing environment often lacks environmental and social complexity. This study examined the effects of early-life, non-maternal adult contact and access to a physically complex environment on the responses of dairy heifers to several stressors, including restraint, social isolation, and novelty at 18 months of age. From the age of 2–13 weeks, 60 dairy heifers (Bos taurus) were reared according to one of three treatments applied to 20 calves each: (1) Hand-reared at pasture in groups of ten, with three unrelated dry cows (+S); (2) Hand-reared at pasture in groups of ten (–S); or (3) Hand-reared in sheds in groups of 10–12 as a commercial control (CC). At 13 weeks, all treatment groups were mixed and managed at pasture as a single herd. At 18 months, the responses of 50 heifers to restraint in a crush, social isolation and a novel object were observed (+S = 16, –S = 17, CC = 17). Treatment did not influence responses to restraint or social isolation, but influenced some indicators of fearfulness during exposure to a novel object. Six +S heifers interacted with the novel object compared to 0 –S and one CC, and CC heifers spent around 50% more time in vigilance than +S or –S heifers. Dairy heifers provided with early-life social enrichment in the form of non-maternal adult contact may have reduced fear of novelty. The implications for lifelong ability to adapt to novel situations, such as entry into the milking herd, should be assessed.

Zoos and aquaria are paying increasing attention to environmental enrichment, which has proven an effective tool for the improvement of animal welfare. However, several ongoing issues have hampered progress in environmental enrichment research. Foremost among these is the taxonomic bias, which hinders our understanding of the value of enrichment for neglected groups, such as reptiles. In this study, we evaluated the status of environmental enrichment for reptiles in European zoos using a survey approach. A total of 121 zoos (32% response rate) completed our main survey, focusing on the use of different enrichment types for reptiles. We found significant differences in the use and/or type of enrichment between reptile groups. Tortoises (family Testudinidae) and monitor lizards (genus Varanus) were the most enriched taxa while venomous snakes were the least. The enrichment types most used across taxa were structural/habitat design and dietary. A second, more detailed, questionnaire followed, where participants were questioned about specific enrichment techniques. A total of 42 enrichment methods were reported, with two being represented across all taxa: increasing structural/thermal complexity and enrichment objects. Finally, we present information from participating zoos on enrichment goals, assessment methods, sources of information for enrichment ideas, and whether enrichment for reptiles is considered essential and/or implemented routinely. Results suggest that, although usage is widespread across European zoos, our understanding of enrichment for reptiles needs to be re-evaluated, since many of the techniques reported tread a fine line between basic husbandry and actual enrichment.

Members of the cat family are highly motivated to hunt, but in captivity are unable to do so for a variety of reasons. This inability to hunt may reduce their welfare. In this study we used a moving bait to stimulate and release hunting motivation in two captive cheetahs (Acinonyx jubatus). Essentially our enrichment device consisted of a dead rabbit, hung from a pulley, just above the ground, moving down a 34 metre length of wire by the force of gravity. We observed the cheetahs for 140 minutes per day over three sequential food presentation periods: Baseline (10 consecutive days), Device (10 consecutive days) and Post-device (5 consecutive days). The moving bait significantly increased the frequency of sprinting (hunting) and time spent performing observations. It significantly decreased time spent in affiliation and feeding. These effects were also observed at times other than when the moving bait was presented. Thus, a moving bait allows captive cheetahs to perform ‘natural-looking’ hunting in captivity.

For captive primates, environmental enrichment may improve psychological well-being, as indicated by changes in the frequency of species-typical and abnormal behaviours. The effects of enrichment on physical well-being have also been examined, but little attention has been devoted to the relationship between enrichment and animal health. We therefore studied the health records of 98 rhesus macaques (Macaca mulatta) to measure the effects that enrichment and social housing manipulations had on the number of veterinary treatments and days of therapy required by the monkeys. Subjects were housed singly, in pairs and in groups. Half of the subjects in each housing condition were enriched and the others were controls. Control and enriched subjects did not differ in the number of treatments they required, but enriched subjects received longer therapies than did controls. Neither treatments nor days of therapy were frequent or randomly distributed across housing conditions; pair-housed subjects required the least treatment and therapy, whereas singly-housed subjects were treated slightly more frequently for diarrhoea-related problems, and group-housed subjects for trauma-related problems. Subject age, however, was a potential confounding factor. Because subjects were part of a specific pathogen-free breeding programme, they spent only certain ages in each housing condition. Results suggest that inanimate enrichment neither diminishes nor improves the health of young macaques, but that enriched monkeys may require longer periods of therapy than do controls. Pair housing may be an effective housing strategy from both veterinary and behavioural points of view, necessitating relatively few treatments, but providing some social enrichment opportunities.

Behavioural management in zoos is often practiced within the confines of environmental enrichment, a well-known method which attempts to increase the welfare of captive animals. For the successful conservation and reintroduction of threatened or endangered species, however, it is also important to manage behaviour in such a way as to maintain behavioural diversity. The development of natural behaviour management (NBM) programs is advocated in this paper. These programs will act to maintain behavioural diversity in captivity and will encourage behaviour to be displayed in appropriate contexts through exposure of captive animals to naturalistic stimuli. The importance of developing appropriate antipredator and predation behaviours will be discussed in order to demonstrate how NBM strategies differ from, and can even conflict with, environmental enrichment strategies undertaken for welfare reasons.

The captive environment is often barren, predictable and under-stimulating so that the behavioural needs of animals in captivity may be thwarted. The welfare of animals may be compromised, which can result in the expression of abnormal behaviours. Stereotypic behaviours, such as the circling or pacing behaviour observed in captive pinnipeds, may become apparent. A simple, cheap and effective method of adding complexity to a captive environment is the use of environmental enrichment techniques. A number of enrichment devices were used in this study, focusing primarily on occupying more time in feeding/foraging behaviours of common seals, Phoca vitulina. The performance of stereotypic circling behaviour was significantly reduced during the enrichment period, suggesting it had improved the welfare of all the animals in this study.

Common marmosets, Callithrix jacchus, are widely used by research laboratories and are commonly provided with food in bowls. These centralised, unchallenging sources of food result in high foraging success for low foraging effort. Foraging devices, which require more skill and effort for foraging success, may broaden the behavioural profiles of marmosets by including more elements of their natural ethogram, reflecting improved welfare. The behaviour of eight female common marmosets was examined as a function of four different food distributions: food centrally located in a stationary bowl; food in a bowl that changed location each day; food centrally located in a stationary bowl, in addition to hidden food in a clustered food source (cluster feeder) or hidden food in dispersed food sources (dispersed feeders). Both the cluster and dispersed feeder distributions increased foraging, and there was a trend for reduced scratching and grooming in the presence of the feeders compared with the bowl-only treatments. The cluster feeder increased the amount of time a marmoset spent in a large room annexed to the home rooms more than the dispersed feeders, and this effect was sustained throughout the day after the feeders had been removed. Both feeders increased activity and movements within all areas of the annexed room compared with the bowl-only treatments; therefore, both feeder types improved the welfare of the captive marmosets more than the provision of food bowls.

The availability and complexity of escape routes are key aspects in modulating aggression. The effect of increased vertical space on the occurrence and severity of aggression was studied in a large group of chimpanzees (Pan troglodytes). Fifty wooden poles were added to the outdoor enclosure at Chester Zoological Gardens, England, UK. Connected with ropes and nets to form a complex vertical structure, they substantially increased the potential for escape routes during aggression. This study is an investigation into whether the use of the new vertical structure reduced the severity of aggression. Aggressive interactions among 29 chimpanzees (five adult males, 15 adult females, and nine immatures) were recorded whenever observed. We found that the proportion of total aggression involving the use of the vertical structure was much lower than expected based on the time individuals spent on the structure. We also found that no severe aggression was initiated when individuals were on the vertical structure. Most importantly, the proportion of severe aggression was lower when recipients of aggression moved onto the vertical structure than when they stayed on the ground. Furthermore, incidents of serious injuries were reduced after the vertical structure was added. The vertical structure appeared to function as a deterrent of aggression and an important escape route during aggressive interactions, which reduced the severity of aggression. Our results suggest that complex vertical structures are highly beneficial for semi-arboreal species with the potential for severe aggression and should be strongly considered by zoos housing such species.

This paper reports a study of the behaviour of captive orang utans (Pongo pygmaeus) at Chester Zoo, UK. The study addressed two questions: what is the effect of the presence of fresh browse on the animals’ behaviour; and what is the effect of the presence of visitors? The first part of the study analysed the animals’ time budgets. The results indicated that the provision of fresh browse led to a decrease in the time spent sitting inactive by both adults and infants; it also led to an increase in the time spent by adults foraging for small food items in the woodchip floor-covering beneath the branches of browse. The time-budget data also showed differences in the animals’ behaviour between periods when large groups of visitors arrived and other periods on the same days when visitors were fewer. Specifically, adults used available paper sacks to cover their heads more during periods of high visitor density, and infants held onto adults more. The second part of the study comprised an experiment in which visitor behaviour was manipulated. Visitor groups of similar sizes were asked to behave either quietly or noisily (making vocal noise), in order to determine whether the observed effects of visitors were attributable to group size or to the fact that larger groups tend to be noisier. The experiment indicated that the animals responded particularly to noise: when confronted with noisy groups, all animals looked more at the visitors, and infants approached and held onto adults more. The findings suggest that zoo managers may need to take visitor behaviour into account in order to promote orang utan welfare.

In nature, mice live in burrows with nest chambers where they breed and may hide from predators. In the laboratory, a shelter or refuge is an easily applicable form of enrichment which may enhance the welfare of laboratory mice by giving them more control over their environment. Six nest boxes made of different materials were evaluated in a preference test with male and female mice of two strains (C57BL/6J and BALB/c). In general, mice showed a preference for cages with a nest box made of grid metal as compared to clear or white perspex nest boxes, or no nest box. They also showed a preference for a cage with a nest box of perforated metal as compared to nest boxes made of grey PVC or sheet metal, or no nest box. When offered a nest box with one open side or a nest box with two open sides, most mice preferred the nest box with one open side and were observed to lie in it with their heads directed towards the opening.

The results of this study show that nest boxes may be used for enrichment purposes in caged mice, although it is not yet entirely clear what are the main features influencing the animals’ preferences. When providing nest boxes as shelters, the structure and design of this type of enrichment should be taken into account, because these may have an effect on the social structure of groups of mice.

Human interaction as environmental enrichment for chimpanzees (Pan troglodytes) and other primates is widely promoted and believed to be of value, but has been subject to little objective evaluation. This study assessed the effects of positive human interaction (eg relaxed treat feeding, playing, and other forms of social interaction compatible with personnel safety) on the behaviour of adult chimpanzees. Subjects were housed indoors in groups of two or three individuals. The level of interaction during routine care and management (ie in the process of cleaning, feeding, and monitoring) represented the baseline condition. The test condition involved a familiar caretaker spending an additional 10 mins per day, 5 days a week, with each chimpanzee. This study was designed to assess carry-over effects of interaction on behaviour outside the context of care staff presence. Therefore, in all phases of the study, data (97 h of focal animal sampling) were collected only when caretakers were absent from the building. During the increased human interaction phase, the chimpanzees groomed each other more and showed lower levels of the following behaviours: regurgitation/reingestion, other oral abnormal behaviours, inactivity, and reactivity to the displays of neighbouring groups. A trend towards reduced agonistic display was also detected. Attempted interactions with the observer shifted significantly from predominantly aggressive to predominantly affiliative in nature. These results suggest that simple, unstructured affiliation between humans and chimpanzees should be a valued component of behavioural management.

The effect of environmental enrichment on the welfare of stabled horses was estimated on the basis of positive and negative behavioural indicators. Six stabled horses were exposed for seven days to each of two conditions in early spring: i) a window at the back of the loose box was opened, but no horses were within the view of the subject horses (OW) and ii) the window in the loose box was opened and two horses that had been in the same stable as the subject horses were turned out to the paddock next to the stable and were within view of the subject horses (OWH). The window in the loose box had been closed prior to the start of the study for protection against the cold during winter months (CW condition) but horses could see outside the loose box through the grille door. The behaviour of the subject horses was recorded by video camera from 1300 to 1530h, firstly, in the CW condition for the three days prior to treatment as the control condition, and then for the last three days of each week in the OW and OWH conditions. The behaviour was focal- and instantaneous-sampled at 30-s intervals. Significant differences between the effects of the loose box conditions on the mean percentage of time spent in standing behaviour, looking behaviour, and bedding investigation behaviour (which may be an indicator of frustration) were observed but no significant difference in the mean percentage of time spent in standing-sleep behaviour (which may be an indicator of behavioural satisfaction) was observed. When the window was opened, bedding investigation and standing behaviour decreased and, when the conspecifics were within view, bedding investigation behaviour decreased and looking behaviour increased. The results suggested that the OW and OWH treatments suppressed the frustration of stabled horses which did not perform any abnormal behaviour, but may not increase the behavioural satisfaction of stabled horses.

The aim of this article is to report on the expert opinion regarding the provision of environmental enrichment for pigs. A questionnaire was sent to 53 pig welfare scientists who were asked to specify which enrichment materials they considered sufficient to ensure pig welfare; 68% responded. 89% stated that providing a chain was not sufficient, while 84% stated that the provision of straw could be sufficient. ‘Sustained animal-material interactions’, ‘rootability’, ‘manipulability’ and ‘chewability’ were the main material properties referred to as being required for enriching pig pens. Areas of further research suggested by the respondents encompassed both fundamental and applied research, including preference tests and demand studies, deprivation studies and quantitative studies to determine cut-off points. A case is made for modelling the available knowledge to help close the gap between what is known in science and what is decided in society regarding animal welfare and environmental enrichment for pigs.

This study examined the effects of enriching the environment on the behaviour and productivity of pigs, in an attempt to assess changes in welfare. A total of 102 pigs were housed in either barren or enriched housing from birth to slaughter. The barren environments were defined as intensive housing and the enriched environments incorporated extra space, an area which contained peat and straw in a rack. Enriching the environment reduced both the amount of time pigs spent inactive and the time involved in harmful social and aggressive behaviour. Tail biting was absent from the enriched environment but four pigs were removed from barren pens with severe tail damage. Pigs housed in enriched environments spent longer durations in exploratory behaviour than those in barren housing, and young pigs in enriched environments performed locomotory behaviour more frequently than their counterparts in barren environments. Overall growth rates were similar in both treatments. These results indicate that welfare is improved by enrichment with substrates and suggest that barren pens should be modified to provide these facilities.

The provisioning of foraging opportunities to primates has been shown to be an effective means of enriching the laboratory environment. In this study artificial turf was used as the substrate for a particulate food given to the subjects as an environmental enrichment technique. Eight rhesus monkeys exhibited a significant reduction in behavioural pathology when allowed to extend the amount of time they spent in consummatory activities. An increasing trend in time spent foraging with a concomitant decline in aberrant behaviour over a period of six months was particularly noteworthy. No significant difference in preference for particulate monkey chow or more flavourful particulate food treats was expressed by the primates.

Rats are a well-understood and widely used laboratory species that should be provided with environmentally enriched caging in line with modern animal welfare guidelines. This paper reviews which sources of enrichment are effective and should be prioritised, and how methods for providing enrichment might be selected using rats’ preferences as a guide. Rats demonstrate high demand for social contact and prefer larger cages, and cages with shelters, nesting material and foraging devices. Rats also discriminate between different methods of providing a given type of enrichment. It is clear that rats should be provided with enrichments such as social contact and shelter, and, in fact, that these should probably be considered basic husbandry requirements rather than optional improvements. It is still difficult, however, for animal caretakers to access proven, standardised methods for providing appropriately enriched caging, and the level of enrichment routinely provided to most rats in the laboratory appears to be low. Further research is required to assess the impact of enrichment upon research variables and to develop commercially viable enrichment products for rats in the laboratory.

Fast-growing broiler chickens use pen-space heterogeneously and have low activity levels, related in part to leg problems. The aim of this study was to test the effects of the addition of string and sand trays to rearing pens on the use of space, levels of activity and leg problems. Broiler chickens were reared in 12 pens (40 birds per pen). Drinkers and feeders only were present in the six control pens (C group), whereas the six other pens were enriched (E group) with two sand trays and string. Behaviour was recorded by scan and focal sampling on days 2-3, 13-14, 23-24 and 34-35. Bodyweight, the occurrence of tarsal deformities and the composition of tibiotarsi were measured on day 37. Chickens from the E group spent more time and stood more often in the area enriched with sand than did the g group birds. ghickens in the E group foraged in the sand throughout the rearing period, and their foraging activities were greater than those of the C group birds. They had little interest in the strings. Locomotor activity during standing bouts was enhanced in the E group on days 2-3 only. Bodyweight at day 37, the occurrence of tarsal deformities and the composition of tibiotarsi were not significantly different between groups. These results indicate that sand could attract chickens into areas that are usually rarely used, which may reduce problems resulting from their heterogeneous distribution. However, the results also indicate the difficulty of stimulating locomotion.

To examine the effect of hay on behaviour of caged rabbits, Oryctolagus cuniculus, a study was carried out on 86 rabbits, kept in wire cages with no access to hay in one period and with access to hay in a second period. As the study was part of a larger experiment analysing the rabbits’ behaviour in two different cage systems, the rabbits were equally distributed across two systems: a system with conventional barren wire cages, and an enriched system with boxes and raised height at the back of the wire cages. The rabbits’ behaviour was recorded using direct scan sampling during the day and continuous registration based on video recording at night. When hay was available, the rabbits in both cage systems performed significantly less bar gnawing and excessive grooming. This applied especially to the rabbits kept in the conventional cage system which also showed a distinct decrease in their frequency of changing between different behaviours. This suggests that rabbits kept in cages where hay is available are less stressed than those kept in cages where it is not. Enrichment with hay should, therefore, be considered in attempts to improve the welfare of caged rabbits.

Chickens were reared in pairs in wooden boxes from 1 to 10 days of age. One chick from each pair was marked to facilitate identification and its position in one or other of the symmetrical halves of the home box was noted at each of 32 visual scans carried out every day. Cumulative sightings in each half were calculated across the first 5 days to establish the least preferred half. Three ‘enrichment’ objects were then placed in the least preferred half of each box on day 6. The chicks ‘positions were again recorded at each of 32 scans on 5 consecutive days. The enrichment objects were avoided on day 6 but such neophobia waned within 24h and a weak, non-significant trend for enrichment to increase usage of the least preferred half became apparent. The strong side preferences shown by the chicks before the introduction of enrichment stimuli, and their transitory neophobia, sound important cautionary notes for the design and assessment of husbandry and environmental enrichment procedures.