A study of animal welfare in 11 species across 16 Zoos using M-AWAG and its correlations with environmental variables

In 2023, there were 114 registered zoos in Korea, more than half of which are small indoor zoos. The welfare conditions of these indoor zoos have become a social issue. The amendment to the Zoo and Aquarium Act in 2023 introduced a licensing system based on the UK's zoo licensing framework, requiring zoos to meet specific criteria in order to obtain an operating license. This study conducts welfare assessments of zoo animals, allowing for the evaluation of the welfare status of each species and the welfare levels associated with the zoo environment. This study assessed animal welfare and microenvironmental conditions in South Korean zoos using a pilot inspector system integrating the Modified Animal Welfare Assessment Grid (M-AWAG) with environmental evaluations. Sixteen zoos were selected from 109 registered facilities, categorized into four groups based on accreditation status and size. Eleven commonly housed species were evaluated to maximize species diversity. Three trained inspectors-a wildlife veterinarian, a zookeeper, and an animal welfare researcher-conducted welfare assessments across four categories: physical, psychological, environmental, and procedural. Environmental variables measured included temperature, humidity, sound levels, illuminance, and odor concentration. The inter-rater reliability among inspectors was 0.942 with high objectivity. Results showed environmental (scores ranging from 4.58 to 6.95), psychological (3.38-4.42), and procedural (3.54-4.78) welfare scores were consistently poorer than physical scores (1.63-2.51) across all species, indicating significant areas for improvement. Analysis of environmental variables showed that illuminance, temperature, and humidity varied significantly among zoo groups Higher sound levels were associated with higher food and drink intake scores (r = 0.28, p < 0.001). High illuminance was negatively correlated with food and drink intake scores (r = -0.24, p = 0.007). Relative humidity was negatively correlated with food and drink intake (r = -0.17, p = 0.046) and activity level (r = -0.18, p = 0.042). The results of this study, conducted as the first pilot project of its kind in Korea, demonstrate that microenvironmental factors can influence animal welfare and highlight the importance of individualized welfare assessments tailored to the ecological and behavioral needs of each species. The standardized welfare assessment protocol developed in this study can provide an empirical basis for evaluating and improving the welfare of animals of various species in domestic zoos, and easily measurable environmental-based assessments-such as temperature, humidity, light, and sound-provide essential data for improving actual animal welfare.