Juvenile Nerodia sipedon sipedon possess a striking dorsal pattern, whereas adults often have a more uniform dorsal coloration. Past researchers have hypothesized that this color shift occurs through a darkening of the ground color, but this hypothesis has never been tested quantitatively. Analysis of digital images of the dorsum and venter of N. s. sipedon individuals of all sizes from islands in Lake Michigan indicated that as snakes increase in length, the dorsal ground color darkens, but the coloration of dorsal blotches and ventral pattern does not change. Potential costs and benefits of a change in dorsal coloration while ventral pattern remains relatively constant are discussed in relation to variation in size.
How to translate text using browser tools
1 December 2003
Ontogenetic Changes in the Coloration of the Northern Watersnake, Nerodia sipedon sipedon
Kenneth D. Bowen
ACCESS THE FULL ARTICLE