THE STRIPED COLOUR PATTERN AND STRIPED/NON‐STRIPED POLYMORPHISM IN SNAKES (REPTILIA: OPHIDIA)

The occurrence of striped colour patterns and of striped/non‐striped polymorphism systems among snakes is reviewed from literature data augmented by some personal observations. Among 1367 species, 190 were striped or had striped morphs. Of 11 families, the striped pattern was common mainly among Colubridae, presumably in relation to the active escape behaviour strategy, prevalent in this family. The striped species tended to cluster in a small number of genera. The 40 striped/non‐striped polymorphism systems found, fall into five categories, according to the coloration patterns of the alternative morphs: (I) blotched (cryptic); (2) barred (or ringed); (3) plain; (4) melanistic; (5) albinistic. Most polymorphisms are presumably maintained by eco‐behavioural trade‐offs, depending on the category and on the habitat: The striped morph is presumed more effective in active escape and sometimes also in camouflage; the alternative morph may be more effective in camouflage, in active escape or in thermoregulation. Hence morph frequency depends on the habitat. Striped‐albinistic polymorphism in Elaphe climacophora presumably depends on human protection of the albino morph.