Managing Aged Animals in Zoos to Promote Positive Welfare: A Review and Future Directions

Monitoring the world-oldest zoo-housed male giant panda (Ailuropoda melanoleuca): A case-study on pathway utilization

Habitat use monitoring is necessary for a comprehensive understanding of the biological and psychological requirements of animals under human care, facilitating improved exhibit designs and promoting animal welfare. Current studies focused on the space use of the exhibit while limited studies examined the pathway use of the zoo-housed animals. This study aimed to investigate the habitat use of An An, the world-oldest male giant panda (Ailuropoda melanoleuca) at Ocean Park Hong Kong using a pathway utilization monitoring method. The result showed uneven utilization of pathways favoring the upper area near his den over the lower area which required longer walking in the hilly exhibit. Moreover, the comparisons of walking directions showed a preference for gentle slopes during uphill movement and a favor for steep slopes during downhill movement. Our study also compared the walking distance between uphill and downhill movements and the results showed that An An walked longer distances heading upward than moving downward due to his choice of pathways. Our results are in line with the findings in the wild population, showing a preference for gentle slopes, especially in uphill movement. Our study demonstrated the value of the pathway monitoring technique. Due to its easy and time-effective use, this technique can be incorporated into the care teams' operation, providing valuable information on daily activity (e.g. accessing the walking ability of the aged animals by investigating the pathway use and walking distance) and habitat use. Consequently, the pathway monitoring technique can help improve exhibit designs promoting welfare.

Quality of Life Assessment: The Value of Longitudinal Data in Making the End-of-Life Care Decision for a Macaque (Macaca Silenus/Macaca Nemestrina)

Assessing quality of life in animals is an art as much as a science. Despite the use of questionnaires and keeper reports which consider several aspects of well-being, the process often remains subjective. Keepers have unique insights, and anecdotal observations can be enhanced with objective data. We combined the art and science of assessments in this study on a geriatric macaque (1.0 lion-tailed/pig-tailed (Macaca silenus/macaca nemestrina) hybrid), using historic data to inform management decisions. Following the unexpected death of his cage mate, his activity and engagement with keepers decreased, and new concerning behaviors presented. While the zoo worked to identify new social opportunities, we used these data to develop a plan to improve his quality of life (e.g., increase training sessions, enrichment, social interactions). After intense implementation, we saw a significant increase in activity level and engagement with keepers; the frequency of unexpected behaviors suggesting a lower quality of life, however, increased over time. Our data allowed us to objectively compare changes in behavior, enabling the zoo to make the most informed animal management decision possible. [Figure: see text].

Nutraceutical supplementation increases mobility in aged captive non-domesticated felids

BACKGROUND

Musculoskeletal diseases (MSDs) are an increasing issue as the lifespan of captive animals increases. Extracts of green-lipped mussels have been linked to alleviation of MSDs in domestic carnivores. Understanding their efficacy in non-domestic felids could provide another tool to improve the welfare of aged individuals in collections.

METHODS

A within-subject study design quantified steps per minute in each of 18 cats of 13 species before and after the addition of a nutraceutical containing green-lipped mussel extract (Antinol) to their diets. The age structure of four commonly kept subspecies of non-domestic cats was quantified to provide a demographic context to the need for managing aged individuals.

RESULTS

Each of the 18 cats exhibited a higher number of steps per minute after the addition of Antinol to their diet. At the group level, a paired t-test showed that the step rate was significantly increased after the addition of Antinol to the diet.

LIMITATIONS

While our results showed a strong significant increase in step rate following Antinol supplementation, further studies that incorporate a placebo, more individuals and more detailed metrics of mobility would provide a more detailed evidence base for practitioners.

CONCLUSION

Nutraceuticals may yield benefits to aged individual felids, including species kept widely in European collections. Their use warrants further, detailed research in collections.

A SYSTEMATIC REVIEW OF RETROSPECTIVE MORBIDITY AND MORTALITY STUDIES ON CAPTIVE WILDLIFE SPECIES

Zoological institutions manage animals for conservation, education, entertainment, and research purposes. Zoological staff have a responsibility to safeguard the welfare of animals in their care. Retrospective morbidity and/or mortality studies (MMSs) can be useful tools to highlight common diseases in captive wildlife populations. There is currently no standardized methodology for conducting MMSs. Variation in the methodology of MMSs, particularly the categorization of diseases, can make comparisons between studies challenging and may limit the applicability of the results. A Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) compliant systematic review was performed, which identified 67 MMSs describing 146 species of captive wildlife. These MMSs are becoming more common and were predominantly performed on mammals (76/146). Prospective authors are encouraged to perform MMSs on amphibians, birds, reptiles, fish, and invertebrates. The studied animals were mostly managed at institutions in the United States of America (28/67, 41.2%) and Europe (14/67, 20.9%). Classifying individuals into age groups facilitates the identification of disease trends within age classes. Only 22/67 (32.8%) studies cited justification for their age classification; classifications should be based on a referenced source on the breeding biology of the studied species. There is variation in the body systems used by authors and into which system a disease is categorized, which makes study comparisons challenging. Diseases were predominantly categorized by etiology and body system (28/77, 36.4%). Because of its ubiquity, the use of the categorization system employed by the pathology module of the Zoological Information Management System is recommended as a useful standard. This system is imperfect, and amendments to it are suggested. The results and recommendations of this study were discussed with a panel of zoo and wildlife experts; guidelines have been formulated for prospective authors aiming to conduct MMSs in captive wildlife.

Quality-of-Life Assessments in Zoo Animals: Not Just for the Aged and Charismatic

Zoos should aim to provide all of their animals with a good quality of life (QoL) throughout all life stages. In parallel with the evolution of QoL assessment questionnaires and tools in human and domestic animal settings, in recent times, some individual zoos and zoo industry associations have incorporated such instruments into their animal management practices. This has been conducted predominantly to inform, monitor, and document end-of-life decision-making for large, charismatic mammals. There is scope to expand the use of these tools to improve their utility, validity, reliability, and value to an animal welfare program. Assessment of QoL is a complex task given that the notion being measured is abstract and self-determined, and the design and purpose of the tools to do this require careful consideration. This review explores the QoL concept as it applies to animals, the assessment indications and methodologies relevant to a zoo setting, and the importance of considering QoL at any life stage across species. An overview of current thinking and the applications and limitations of QoL evaluation of captive wild animals is offered to promote and aid facility practice reviews and to help direct future innovations that leverage concurrent and converging advances in zoo animal welfare science.

Survival improvements of marine mammals in zoological institutions mirror historical advances in human longevity

An intense public debate has fuelled governmental bans on marine mammals held in zoological institutions. The debate rests on the assumption that survival in zoological institutions has been and remains lower than in the wild, albeit the scientific evidence in support of this notion is equivocal. Here, we used statistical methods previously applied to assess historical improvements in human lifespan and data on 8864 individuals of four marine mammal species (harbour seal, Phoca vitulina; California sea lion, Zalophus californianus; polar bear, Ursus maritimus; common bottlenose dolphin, Tursiops truncatus) held in zoos from 1829 to 2020. We found that life expectancy increased up to 3.40 times, and first-year mortality declined up to 31%, during the last century in zoos. Moreover, the life expectancy of animals in zoos is currently 1.65-3.55 times longer than their wild counterparts. Like humans, these improvements have occurred concurrently with advances in management practices, crucial for population welfare. Science-based decisions will help effective legislative changes and ensure better implementation of animal care.

Promoting Good Nonhuman Primate Welfare outside Regular Working Hours

Promoting good primate welfare outside of daylight hours is an important task. The responsibility to provide a complex environment and environmental enrichment is an essential element of primate wellbeing programs that should be approached from a 24-h perspective and planned according to the species and individual needs, including giving animals the ability to interact with and control their environment during hours when animal care staff are not present. One must be aware, however, that their needs may differ at night-time from their care needs during the day when staff are present. Assessing welfare and providing enrichment during times when staff are not on hand can be achieved through the use of a variety of technologies, such as night-view cameras, animal-centred technologies, and data loggers. This paper will address the relevant topics concerning the care and welfare of primates during off-hours, and the use of related technologies to facilitate and assess wellbeing at these times.

Review of the Effects of Enclosure Complexity and Design on the Behaviour and Physiology of Zoo Animals

The complexity of the habitat refers to its physical geometry, which includes abiotic and biotic elements. Habitat complexity is important because it allows more species to coexist and, consequently, more interactions to be established among them. The complexity of the habitat links the physical structure of the enclosure to the biological interactions, which occur within its limits. Enclosure complexity should vary temporally, to be able to influence the animals in different ways, depending on the period of the day and season and throughout the year. In the present paper, we discuss how habitat complexity is important, and how it can positively influence the physical and mental states of zoo animals. We show how habitat complexity can ultimately affect educational projects. Finally, we discuss how we can add complexity to enclosures and, thus, make the lives of animals more interesting and functional.

Extracellular vesicle: A magic lamp to treat skin aging, refractory wound, and pigmented dermatosis?

Exposure of the skin to an external stimulus may lead to a series of irreversible dysfunctions, such as skin aging, refractory wounds, and pigmented dermatosis. Nowadays, many cutaneous treatments have failed to strike a balance between cosmetic needs and medical recovery. Extracellular vesicles (EVs) are one of the most promising therapeutic tools. EVs are cell-derived nanoparticles that can carry a variety of cargoes, such as nucleic acids, lipids, and proteins. They also have the ability to communicate with neighboring or distant cells. A growing body of evidence suggests that EVs play a significant role in skin repair. We summarize the current findings of EV therapy in skin aging, refractory wound, and pigmented dermatosis and also describe the novel engineering strategies for optimizing EV function and therapeutic outcomes.

Island Life: Use of Activity Budgets and Visibility to Evaluate a Multi-Species Within-Zoo Exhibit Move

Simple Summary

Modern zoos aim to provide the best facilities possible for their animals, staff and visitors. Here, we present findings from a study focusing on the behaviour and visibility of four species pre- and post-translocation to a new environment, Islands, within Chester Zoo, UK: the Sumatran orangutan (Pongo abelii), crested macaque (Macaca nigra), Malayan tapir (Tapirus indicus) and the Malayan sun bear (Helarctos malayanus). We used full activity budgets to demonstrate that the move to new, custom-built facilities influenced the behaviour of all four species. Following relocation, both non-human primate species were found to spend more time interacting socially with group members and abnormal behaviours remained low for all four species. Malayan tapirs and crested macaques chose to spend more time in areas out of public view post-move, whilst Malayan sun bears were more visible to visitors in their new environment. We demonstrate the value of giving animals choice and control over how they interact with their surroundings, the importance in investment in behavioural monitoring throughout translocation events and add to the knowledge-base of this understudied area.

Abstract

Modern zoos strive to construct habitats which both enable and encourage animals to engage in species-specific behaviour, without compromising their visibility to visitors. Here, we present the findings of a within-zoo move to a custom-built exhibit (Islands at Chester Zoo, UK) with respect to the behaviour of four mammal species; the Sumatran orangutan (Pongo abelii), crested macaque (Macaca nigra), Malayan tapir (Tapirus indicus) and the Malayan sun bear (Helarctos malayanus). We used full activity budgets along with Compositional Data Analysis (CoDA) to gain insight into how the move to a more naturalistic exhibit influenced behaviour. Engagement in abnormal behaviour remained low during the study period for all four species, suggesting no adverse responses to the change in environment. Following the move, both the non-human primate species spent more time engaged in positive social interactions with conspecifics, highlighting the importance of social support during enclosure moves. Time spent visible to the public was largely unaffected by the enclosure move for the Sumatran orangutan, whilst the movement to a new environment increased visibility for the Malayan sun bear and decreased visibility for the crested macaque and Malayan tapir. We demonstrate the value of monitoring behaviour throughout the translocation of zoo-housed species and outline the positive behavioral impacts of providing individuals with naturalistic, species-appropriate environments.

A dynamic concept of animal welfare: The role of appetitive and adverse internal and external factors and the animal’s ability to adapt to them

Animal welfare is a multifaceted issue that can be approached from different viewpoints, depending on human interests, ethical assumptions, and culture. To properly assess, safeguard and promote animal welfare, concepts are needed to serve as guidelines in any context the animal is kept in. Several different welfare concepts have been developed during the last half decade. The Five Freedoms concept has provided the basis for developing animal welfare assessment to date, and the Five Domains concept has guided those responsible for safeguarding animal welfare, while the Quality of Life concept focuses on how the individual perceives its own welfare state. This study proposes a modified and extended version of an earlier animal welfare concept - the Dynamic Animal Welfare Concept (DAWCon). Based on the adaptability of the animal, and taking the importance of positive emotional states and the dynamic nature of animal welfare into account, an individual animal is likely in a positive welfare state when it is mentally and physically capable and possesses the ability and opportunity to react adequately to sporadic or lasting appetitive and adverse internal and external stimuli, events, and conditions. Adequate reactions are elements of an animal’s normal behavior. They allow the animal to cope with and adapt to the demands of the (prevailing) environmental circumstances, enabling it to reach a state that it perceives as positive, i.e., that evokes positive emotions. This paper describes the role of internal as well as external factors in influencing welfare, each of which exerts their effects in a sporadic or lasting manner. Behavior is highlighted as a crucial read-out parameter. As most animals under human care are selected for certain traits that may affect their behavioral repertoire it is crucial to have thorough ethograms, i.e., a catalogue of specific behaviors of the species/strain/breed under study. DAWCon highlights aspects that need to be addressed when assessing welfare and may stimulate future research questions.

Welfare Through Competence: A Framework for Animal-Centric Technology Design

Digital technologies offer new ways to ensure that animals can lead a good life in managed settings. As interactive enrichment and smart environments appear in zoos, farms, shelters, kennels and vet facilities, it is essential that the design of such technologies be guided by clear, scientifically-grounded understandings of what animals need and want, to be successful in improving their wellbeing. The field of Animal-Computer Interaction proposes that this can be achieved by centering animals as stakeholders in technology design, but there remains a need for robust methods to support interdisciplinary teams in placing animals' interests at the heart of design projects. Responding to this gap, we present the Welfare through Competence framework, which is grounded in contemporary animal welfare science, established technology design practices and applied expertise in animal-centered design. The framework brings together the “Five Domains of Animal Welfare” model and the “Coe Individual Competence” model, and provides a structured approach to defining animal-centric objectives and refining them through the course of a design project. In this paper, we demonstrate how design teams can use this framework to promote positive animal welfare in a range of managed settings. These much-needed methodological advances contribute a new theoretical foundation to debates around the possibility of animal-centered design, and offer a practical agenda for creating technologies that support a good life for animals.

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.

Management of Dental Disease in Aardvarks (Orycteropus afer) and Potential Use of Cone-Beam Computed Tomography

Oral disease involving teeth is a common cause of morbidity in aardvarks (Orycteropus afer) under managed care. Cases can be challenging due to the species’ unique skull and dental anatomy and limited veterinary literature. A retrospective evaluation was performed on dental examinations in nine aardvarks housed at a single zoological institution in the United States between 1995 and 2021. The prevalence of dental disease in this population was 88%, with most cases categorized as mild (4/8). Clinical signs were only seen in three cases. Facial swelling prior to surgery was the most common clinical sign (3/8). Dental pathology was more common in the mandibular teeth (27/38) compared to the maxillary teeth (11/38). Dental abnormalities found upon intraoral examination included the presence of dental points (7/8), crown elongation (3/8), purulent material within the oral cavity (4/8), loose teeth (2/8), periodontal pockets (2/8), and oronasal fistula (1/8). Three patients required dental extractions with a lateral buccostomy approach. Diagnostic imaging was performed in most cases (7/8), with two cases undergoing cone-beam computed tomography (CBCT) to characterize dental pathology that was difficult to fully evaluate with standard radiography. Tomographic findings are described in both cases. CBCT was found to be a helpful tool for diagnosing and characterizing dental disease in aardvarks.

Acupuncture and Traditional Chinese Veterinary Medicine in Zoological and Exotic Animal Medicine: A Review and Introduction of Methods

Acupuncture has been used extensively in domestic animal medicine to treat a variety of medical conditions and diseases as an adjunct or primary therapy. Exotic animals are becoming increasingly common as pets. Owners are expecting therapies for these non-domestic animals to be similar to those available to their other domestic pets. Additionally, zoological and aquatic facilities provide medical care for the entire lives of the animals that are housed in their facilities. Many conditions similar to those observed in domestic animals can develop in zoological species and can benefit from treatment with acupuncture. Through operant conditioning or routine medical examinations, the use of acupuncture as an adjunct therapy is becoming more common. The following paper presents a summary of the types of non-domestic animals treated, for which conditions, and how these methods are commonly used.

Using Keeper Questionnaires to Capture Zoo-Housed Tiger (Panthera tigris) Personality: Considerations for Animal Management

Individual personalities affect animal experiences of zoo environments, impact on an animal’s coping ability and have potential implications for welfare. Keeper assessments have been identified as a quick and reliable way of capturing data on personality in a range of species and have practical application in improving animal welfare on an individual level. Despite widespread recognition of the importance of animal personality within a zoo environment, there is a paucity of research into tiger personality and the potential impact of this on tiger experiences within zoos. This research investigated the personality of 34 tigers (19 Amur and 15 Sumatran) across 14 facilities in the UK using keeper ratings and identified changes keepers made in animal husbandry to support tiger welfare. Reliability across keepers (n = 49) was established for nine adjectives and a principal component analysis identified three personality components: ‘anxious’, ‘quiet’ and ‘sociable’. When subspecies were combined, there was no relationship between tiger scores on the personality components and age or sex of tigers (p > 0.05). Subspecies of tiger was not related to scores on the ‘quiet’ or ‘sociable’ components (p > 0.05). Sumatran tigers scored more highly than Amur tigers on the ‘anxious’ component (mean ± SD, Sumatran: 3.0 ± 1.7, Amur: 1.8 ± 0.6, p < 0.05). Analysis within subspecies found that male Amur tigers were more sociable than females (mean ± SD, males: 5.5 ± 0.707; females: 4.15 ± 0.55). Amur tiger age was also negatively correlated with scores on the sociable personality component (R = −0.742, p < 0.05). No significant differences were seen in Sumatran tigers. Keepers reported a number of changes to husbandry routines based on their perceptions of their tigers’ personality/needs. However, there was no significant relationship between these changes and tiger personality scores (p > 0.05). Despite significant evolutionary differences between Amur and Sumatran tigers, there are no subspecies specific guidelines for zoo tigers. This research has highlighted the potential for these two subspecies to display personality differences and we advocate further research into this area. Specifically, we highlight a need to validate the relationship between tiger personality, management protocols and behavioural and physiological metrics of welfare. This will enable a fuller understanding of the impact of personality on zoo tiger experiences and will enable identification of evidence-based best practice guidelines.

Social Behaviour in Zoo Bachelor Groups: A Case Study of Related South American Fur Seals

Simple Summary

Appropriate management of social groups is one of the greatest challenges that face zoos and aquaria worldwide. All-male social groups provide an opportunity for facilities to house surplus males in groups which optimise their welfare whilst they are being retained for future use in breeding programmes. Here, we investigated social behaviour in a relatively poorly studied species, the South American fur seal (SAFS). Four individuals housed in a related group were studied over a 6-month period. The results showed that their social relationships changed over time, although the individuals always engaged in more positive than negative interactions. We recommend establishing baseline social behaviour profiles of individuals to enable long-term monitoring of SAFS social groups, as has been recommended in other species. This will enable enhanced understanding of South American fur seals and will contribute to the development of evidence-based social management guidelines for this species.

Abstract

Appropriate management of social groups is one of the greatest challenges that face zoos and aquaria worldwide. To facilitate breeding programmes, particularly in polygynous species, there is a need to house surplus males in bachelor groups, yet for pinnipeds, the social impact of this management strategy is unknown. The aim of this research was to enhance understanding of sociality in South American fur seals (SAFSs), with a particular focus on social dynamics in a related bachelor group, and consider implications for evidence-based management of this species in zoos. The subjects were four related male seals housed at Bristol Zoo Gardens. Social interaction and nearest neighbour data were collected between February and July 2019. Individuals engaged in both positive and negative social interactions. Positive interactions were more frequent than negative interactions, and no excessive negative interactions were observed. Temporal dynamics were observed in social relationships, and negative interactions did not increase with the onset of the breeding season. Reciprocity in dyadic relationships was variable across the study months, and nearest neighbours were not necessarily reflective of social partners. This research highlights the importance of longitudinal monitoring of social relationships and establishment of baseline social behaviour profiles to support evidence-based species management. We advocate that this research is extended, to further develop our understanding of SAFS social needs within zoo environments, to understand the differences between single-sex and mixed-sex groups and to identify the degree to which the extensive research conducted in other polygynous species (e.g., gorillas) is applicable in the social management of South American fur seals moving forwards.

SURVEY OF GERIATRIC ELEPHANT MEDICAL CARE, NUTRITION, HUSBANDRY, AND WELFARE

Improvements in husbandry, veterinary care, and nutrition have led to increased longevity of animals in human care, including elephants. The goal of this study was to collect and synthesize information pertaining to geriatric elephant medicine, management, husbandry, and nutrition. An electronic survey was created and distributed to American Association of Zoo Veterinarians members through an online link. A total of 61 responses were received from veterinarians, nutritionists, and elephant managers with data encompassing 314 elephants, of which 142 were geriatric (over 40 years old) and 51 were on their final set of molars. Following the initial survey, willing respondents were contacted for follow-up interviews. Osteoarthritis, foot disease, and colic were the most commonly reported diseases, and flunixin meglumine and phenylbutazone were the analgesics most often used. Respondents described diseases treated, husbandry changes specific for older animals, welfare assessments and quality of life monitoring, nutritional modifications for dental attrition, a variety of integrative medicine modalities, and unique cases. It is the hope that the information identified in this study can be used to improve treatment, management practices, and overall welfare for geriatric elephants.

Understanding Temporal Social Dynamics in Zoo Animal Management: An Elephant Case Study

Zoo animal management procedures which lead to changes to social groups can cause disruption in social hierarchies and the temporary breakdown of social relationships. Animals have different roles in social networks. Understanding individual positions in social networks is important for effective management and ensuring positive welfare for all animals. Using elephants as a case study, the aim of this research was to investigate temporal social dynamics in zoo animals. Behavioural data were collected between January 2016 and February 2017 from 10 African and 22 Asian elephants housed at seven zoos and safari parks in the UK and Ireland. Social interactions were defined as positive physical, positive non-physical, negative physical or negative non-physical. Social network analysis explored social relationships including the fluidity of networks over time and dyadic reciprocity. Social interaction networks were found to be fluid but did not follow a seasonal pattern. Positive interaction networks tended to include the entire social group whereas negative interactions were restricted to specific individuals. Unbalanced ties were observed within dyads, suggesting potential inequalities in relationships. This could impact on individual experiences and welfare. This research highlights subtle temporal dynamics in zoo elephants with the potential for species-level differences. Similar temporal dynamics may also be present in other socially housed zoo species. This research thus provides evidence for the importance of understanding the social networks of zoo animals over longer periods of time. Understanding social networks enables pro-active and evidence-based management approaches. Further research should seek to identify the minimum sampling efforts for social networks in a range of species, to enable the implementation of regular monitoring of social networks and thus improve the welfare of social species under human care.

What Is so Positive about Positive Animal Welfare?-A Critical Review of the Literature

Simple Summary

Positive animal welfare (PAW) is thought to have come about as a response to there being too much of a focus on avoiding negatives in animal welfare science. However, despite its development over the last 10 years, it is not clear what it adds to the study of animal welfare. To clarify this, we conduct a review of the literature on PAW. We aim to identify the characteristic features of PAW and to show how PAW connects to the wider literature on animal welfare. We find that the PAW literature is characterised by four features: (1) positive emotions which highlights the capacity of animals to experience positive emotions; (2) positive affective engagement which seeks to create a link between positive emotions and behaviours animals are motivated to engage in; (3) quality of life which acts to give PAW a role in defining an appropriate balance of positives over negatives and; (4) happiness which brings a full life perspective to PAW. While the first two are already well situated in animal welfare studies the two last points open research agendas about aggregation of different aspects of PAW and how earlier experiences affect animals’ ability to have well-rounded lives.

Abstract

It is claimed that positive animal welfare (PAW) developed over the last decade in reaction to animal welfare focusing too much on avoiding negatives. However, it remains unclear what PAW adds to the animal welfare literature and to what extent its ideas are new. Through a critical review of the PAW literature, we aim to separate different aspects of PAW and situate it in relation to the traditional animal welfare literature. We find that the core PAW literature is small (n = 10 papers) but links to wider areas of current research interest. The PAW literature is defined by four features: (1) positive emotions which is arguably the most widely acknowledged; (2) positive affective engagement which serves to functionally link positive emotions to goal-directed behavior; (3) quality of life which serves to situate PAW within the context of finding the right balance of positives over negatives; (4) happiness which brings a full life perspective to PAW. While the two first points are already part of welfare research going back decades, the two latter points could be linked to more recent research agendas concerning aggregation and how specific events may affect the ability of animals to make the best of their lives.

Social Interactions in Zoo-Housed Elephants: Factors Affecting Social Relationships

Elephants have complex social systems that are predominantly driven by ecological factors in situ. Within zoos, elephants are held in relatively static social groups and the factors observed driving social relationships in the wild are largely absent. Little research has investigated the effect of social group factors in zoos on elephant social interactions. The aim of this research was to establish whether there is a relationship between social group factors and social behaviour, in order to identify factors that make elephant herds more or less likely to be compatible. Results will facilitate recommendations for optimum social groupings for zoo elephants. Behavioural data quantifying social interactions were collected between January 2016 and February 2017 at seven UK and Irish zoos and safari parks from 10 African and 22 Asian elephants. Social interactions were split into four categories: positive physical, positive non-physical, negative physical and negative non-physical. Social interactions were related to age (positive physical higher and negative non-physical lower in calves than adults), personality (elephants with higher sociability scores engaged in more positive interactions and less negative interactions), presence of calves in the herd (herds with calves had more positive non-physical), relatedness to other elephants in the herd (positive non-physical were higher when relatives were in the group and negative non-physical were higher between unrelated elephants) and species (Asian elephants engaged in more positive non-physical than African elephants). A greater understanding of factors that may contribute to the success of zoo-elephant social groups is important for individual and herd welfare as it will enable evidence-based decisions which have minimal impact on social structures to be executed. This knowledge will enable proactive management approaches to be undertaken and will thus be paramount in ensuring optimal welfare for elephant herds moving forwards.

A Review of Welfare Assessment Methods in Reptiles, and Preliminary Application of the Welfare Quality® Protocol to the Pygmy Blue-Tongue Skink, Tiliqua adelaidensis, Using Animal-Based Measures

Reptiles are held at wildlife parks and zoos for display and conservation breeding programs and are increasingly being kept as pets. Reliable indicators of welfare for reptiles need to be identified. Current guidelines for the captive management of reptiles utilize resource-based, rather than animal-based indicators; the latter being a more direct reflection of affective state. In this paper we review the literature on welfare assessment methods in reptiles with a focus on animal-based measures. We conclude that, whilst a number of physiological and behavioral indicators of welfare have been applied in reptiles, there is need for further validation of these methods across the diversity of species within the Class. Methods of positive welfare state assessment are comparatively understudied and need elucidation. Finally, we examine some widely-used welfare assessment tools in mammals and explore the application of the Welfare Quality^® Protocol to the endangered pygmy blue-tongue skink, Tiliqua adelaidensis. We propose that this framework can form the basis for the development of taxon-specific tools with consideration of species-specific biology.