Racers – Ontogenetic Shifters
Back when I was lucky enough to teach the Herpetology lab at the University of Georgia, I made it a point to find a juvenile racer to put on the lab practical final. Very, very few students ever got the right answer for the confusing little snake. When you talk about racers, most people envision a long, thin, and BLACK snake. This is not always the case. Racers span across most of the United States from the Atlantic Ocean to the Pacific Ocean and can be black, tan, blue, olive, green, buttermilk, and even grayish. They come in many colors as adults but it is their juvenile coloration and the drastic change they undergo that is striking to me.
Racers start life with a bold pattern that they slowly lose over the next two years of growth. Even with the striking differences in adult coloration, the baby racers across this species range all look very similar. Check out the photos below of an Eastern Yellow-bellied Racer as a juvenile, sub-adult, and then adult as an example. Each subspecies of racer undergo a similar change. Ontogenetic color changes are not unique to racers and other species of snakes also go through a similar changes. I will try to highlight a few of these in the near future.
Do you have photos of juvenile racers? If so and you would like to share them, please email them to firstname.lastname@example.org and I will share them with the Center for Snake Conservation community.
Center for Snake Conservation