Citizen Science, taxonomy and grass snakes: iNaturalist helps to clarify variation of coloration and pattern in Natrix natrix subspecies

Coloration and pattern of Natrix natrix natrix documented by photos from iNaturalist. A Individual with plain dark grey body; Biosphärenreservat Schorfheide-Chorin, Germany; photo: cloudya. B Individual with spotted grey body; Bernau near Berlin, Germany; photo: koha1. C Individual with black body; Lillerød, Denmark; photo: petersc. D Nearly melanistic individual; Solängen, Mölndal, Sweden; photo: Janne Asp. E Individual with marbled grey body; Garstedt, Germany; photo: vasquez. F Individual with marbled dark grey body; Ebeltoft, Denmark; photo: Oskar Liset Pryds Hansen.