Selection of parameters to assess the welfare of free-ranging Indo-Pacific humpback dolphins using expert opinion survey

Animal welfare assessments have recently been suggested to be useful for free-ranging animals. Nevertheless, few standardized welfare assessment frameworks have been built for wildlife, including cetaceans. Coastal cetaceans like Indo-Pacific humpback dolphins (Sousa chinensis, IPHDs) that form resident populations impacted by a wide range of human activities are subject to reliable photo-identification efforts and thus represent perfect candidates for welfare monitoring. Parameters that may inform us on some aspects of the welfare of free-ranging IPHDs were selected through literature review. A panel survey including three consecutive rounds was then conducted to collect the opinion of selected experts on these parameters. The survey allowed the validation of a list containing 31 parameters that provide information on the welfare of IPHDs. The opinion of experts also allowed to set the modalities of the data collection required to measure/observe these parameters. After establishing a consistent scoring method and testing it on existing data, this standardized framework will allow for obtaining a wide picture of the living conditions of IPHDs. Variations across time periods, among dolphin populations and locations, or following major environmental changes (e.g., conservation measures or human disturbances) could then be analysed. Added to traditional conservation approaches, standardized welfare monitoring will greatly participate in the conservation of these animals.