ABSTRACT Understanding the health of wild animals is crucial for conservation. Body condition scoring (BCS) is a useful tool to access information on the nutritional state and health of individual animals. This study developed and validated a photograph‐based BCS method for Indo‐Pacific humpback dolphins ( Sousa chinensis ), a vulnerable coastal species facing multiple anthropogenic threats. Photographs from boat‐based surveys in the Pearl River Delta, Beibu Gulf, and Leizhou Bay were used to create a two‐point BCS scale based on the prominence of epaxial musculature in mid‐section photographs. Reliability, including intrarater, interrater, test‐retest reliability, and internal consistency was tested through different photograph ratings by an experienced panel to ensure the method's robustness, and construct validity was assessed through the comparison of body ratios obtained from unmanned aerial vehicle footage with the BCS scores attributed based on photographs. While the presented BCS scale can be further extended as more extreme cases (i.e., fatter or thinner individuals) are encountered, the different tests allowed for validating its reliability and biological meaning. This photographic BCS provides a valuable, noninvasive tool for monitoring the health and nutritional status of Indo‐Pacific humpback dolphin populations and informing conservation management strategies.
Serres et al. (Thu,) studied this question.