The First Standardized Scoring System to Assess the Welfare of Free-Ranging Indo-Pacific Humpback Dolphins (Sousa chinensis)

The assessment of wild animal welfare has recently gained interest and represents a novel, complementary approach to monitoring free-ranging populations for conservation purposes. However, few attempts have been made to develop standardized welfare assessment tools for free-ranging animals. In the present study, a preliminary scoring system for the welfare assessment of Indo-Pacific humpback dolphins (IPHDs) was created using the Five Domains Model. During a series of online meetings, the panel established the scoring unit, the contribution of each parameter to the four physical/functional domains, the inferred mental states and impact intensity associated with each of these parameters, and the method of aggregating parameter scores within and among domains. The resulting framework includes a total of 53 parameter scores. A total of 20 welfare-status and 33 welfare-alerting parameters were identified; these are aggregated into two overall welfare grades for enhancement (positive experiences) and compromise (negative experiences). The panel attributed confidence scores to the intensity impact reflected by each parameter and associated mental states. As expected, these scores reflect higher confidence in welfare-status than welfare-alerting parameters; welfare compromise was also attributed higher confidence than welfare enhancement and Domain 1 (Nutrition) globally received higher confidence scores than other domains. As with any expert elicitation study, subjective biases likely exist; these can be reduced through further research on the suggested parameters. The framework uses current knowledge and has been developed to enable continual improvement as further evidence becomes available on various parameters. This study represents an important step in the development of a welfare assessment tool (WAT) for IPHDs. Next steps include defining measurement methods and thresholds for scoring parameter intensities, followed by reliability testing. This WAT can then be used to systematically monitor populations of IPHDs in a way that will better inform conservation measures and ensure their effectiveness.