Boa sigma
—
Mexican West Coast Boa Constrictor
This species used to be considered a subspecies of Boa constrictor, which is one of those rare species whose scientific name is the same as its standard English name. Then the ones in this area were considered part of a species that was split from Boa constrictor, called Boa imperator. And then this was further split in 2016, leaving Boa imperator in Central America and Boa sigma in Mexico (basically).
This was the snake species I most hoped to see on this trip. They aren't rare by any means, but they are iconic (though slightly less iconic after they were split out from Boa constrictor, which is now confined to South America). I hadn't come across any Boa in my various travels to Costa Rica, Belize, Peru, southern Florida, etc., and we had been looking for a few nights before coming across this docile fellow. I don't know why it decided to try to climb up into the sky. Perhaps it thought it was a lyre snake.
Online references:
- Boa sigma account on The Reptile Database
- Boa sigma account on iNaturalist
Printed references:
- Heimes, P. 2016. Snakes of Mexico
- Rorabaugh, J.C., Lemos-Espinal, J.A. 2016. A Field Guide to the Amphibians and Reptiles of Sonora, Mexico