Differing animal welfare conceptions and what they mean for the future of zoos and aquariums, insights from an animal welfare audit

Animal welfare is a growing public concern that has the potential to undermine the social license of zoos and aquariums. The lack of consensus on how animal welfare is defined across such a diverse sector combined with and a widespread belief that commercial priorities such as entertaining visitors conflicts with animal welfare, hinders efforts to effectively address this fundamental issue for the sector. Data derived from an audit of habitats across a major North American wildlife attraction revealed that holistic animal welfare assessments undertaken by animal carers embracing three principal constructs of animal welfare, correlated strongly with visitor perceptions of animal happiness. Visitor assessments of animal happiness also correlated with animal carer assessments of social, behavioural and locomotor opportunities and inversely with the prevalence of stereotypic behaviours, supporting the proposition that folk conceptions of animal welfare are more accurate than may have previously been considered to be the case. However, the holistic animal welfare assessment inversely correlated with assessments of a habitat's capacity to safeguard welfare as determined by the facility's veterinary staff, supporting the proposition that tensions exist between physical and psychological components of captive animal welfare provisioning. This further underlines the importance of clarity on how animal welfare is conceived when developing institutional animal welfare strategies. Finally, the data also showed that both holistic animal welfare assessments and visitor perceptions of animal happiness strongly correlated with the level of enjoyment experienced by visitors, challenging the belief that animal welfare competes with the commercial priorities of zoos and aquariums. The audit supports the case that maintaining high animal welfare is a commercial imperative as well as a moral obligation for zoos and aquariums and underlines the necessity to utilize conceptions of animal welfare that acknowledge the centrality of the affective states of animals in maintaining those standards.

In pursuit of peak animal welfare; the need to prioritize the meaningful over the measurable

Despite the diversity of animal welfare definitions, most recognise the centrality of the feelings of animals which are currently impossible to measure directly. As a result, animal welfare assessment is heavily reliant upon the indirect measurement of factors that either affect what animals feel, or are effected by how they feel. Physiological and health orientated measures have emerged as popular metrics for assessing welfare because they are quantifiable, can effect and be affected by how animals feel and have merits regardless of their relationship to the feelings of animals. However, their popularity in animal welfare assessment has led to them having a disproportionate influence on animal management to the detriment of animal welfare in numerous instances. Here, the case is made that a tension exists between management that prioritizes aspects of care reflecting popular animal welfare metrics such as those relating to physical health, and management that emphasizes psychological wellbeing. By re-examining the relative merits of physical and psychological priorities in animal management, an alternate animal welfare paradigm emerges less tied to traditional welfare metrics. This paradigm theorizes about the possibility for an optimal animal welfare state to exist where managed animal populations provided essential psychological outlets but protected from key physical stressors routinely experienced in the wild, might experience higher levels of welfare than wild populations would routinely experience. The proposition that optimal animal welfare could theoretically be achieved in well managed and well designed captive environments challenges a widely held ethical perspective that captivity is inherently bad for animal welfare.

What do population-level welfare indices suggest about the well-being of zoo elephants?

To assess zoo elephants' welfare using objective population-level indices, we sought data from zoos and other protected populations (potential "benchmarks") on variables affected by poor well-being. Such data were available on fecundity, potential fertility, stillbirths, infant mortality, adult survivorship, and stereotypic behavior. Most of these can also be affected by factors unrelated to well-being; therefore, for each, we analyzed the potential role of these other factors. Population-level comparisons generally indicate poor reproduction, and poor infant and adult survivorship in zoos compared with benchmark populations (with some differences between zoo regions and over time). Stereotypic behavior also occurs in c. 60% of zoo elephants; as the population-level welfare index least open to alternative interpretations, this represents the strongest evidence that well-being is/has been widely compromised. Poor well-being is a parsimonious explanation for the diverse range of population-level effects seen, but to test this hypothesis properly, data are now needed on, for example, potential confounds that can affect these indices (to partition out effects of factors unrelated to well-being), and causes of the observed temporal effects, and differences between species and zoo regions. Regardless of whether such additional data implicate poor well-being, our findings suggest that elephant management has generally been sub-optimal. We also discuss the selection and utilization of benchmark data, as a useful future approach for evaluating such issues.

A reassessment of the effect of body mass upon flight speed and predation risk in birds

A number of theoretical studies have predicted that avian predation risk is mass dependent. Models of bird flight predict that increased mass will reduce flight velocity, making birds more vulnerable to predation. Empirical studies supporting this have demonstrated a significant relationship between mass and routine flight velocity (when birds are not alarmed). Studies investigating the effects of mass upon flight velocity when birds are alarmed, however, tend to show that the mass/velocity relationship is less marked. We found a real difference in the relationship between mass and flight velocity in zebra finches, Taeniopyga guttata, when comparing flights of alarmed and unalarmed birds. Despite the strong mass/routine velocity relationship already shown for zebra finches, mass tended to be a poor predictor of the flight velocity of alarmed birds within the natural weight range of the species. This difference appeared to be partly due to alarmed birds increasing their velocity more when heavy than when light, in comparison to their respective predicted routine flight velocities for their weights. As a result, mass/velocity regression slopes tended to be more shallow for alarmed birds. Consequently, increases in body mass within the natural weight range of a bird, may have less effect on the flight velocities of alarmed birds than they do on routine flight velocities. We therefore recommend caution in the use of weight as a predictor of predation risk in birds without examining its effects upon the flight velocity of alarmed birds. We suggest some explanations for the differences in the mass/velocity relationship between the flights of alarmed and unalarmed birds. Copyright 1998 The Association for the Study of Animal Behaviour.