Community science data highlight the vast colour pattern variations in the Japanese natricine snake (Rhabdophis tigrinus).

This article focuses on the use of community science (citizen science) data to refine and expand the understanding of colour pattern variation in the Japanese natricine snake, *Rhabdophis tigrinus*, across the Japanese Archipelago. Previously, *R. tigrinus* was classified into six discrete colour morphs based on limited regional observations, but analysis of 508 community-sourced images revealed 123 distinct colour pattern combinations, indicating a continuous spectrum rather than discrete morphs. The study also found that these colour patterns are distributed broadly beyond previously defined regional boundaries and that blotch size correlates positively with habitat temperature, challenging prior assumptions about thermal adaptation. The findings demonstrate the value of community science in overcoming sampling biases and provide new insights into the ecological and geographical variation of *R. tigrinus* colouration.