Eric Centenero Alcala
Mexican Lance-Headed Rattlesnake
Federal and State Protections
Countries of Occurrence
States or Providence
This small-to-medium-sized rattlesnake species can be found on the plateau of Central Mexico. at elevations of 4,500 to 8,500 ft. They occur in a variety of habitats from grasslands to pine-oak forests and rocky lava outcrops. This rather colorful rattlesnake species can be more tan, brown, gray, or white as a background to their distinctive "lancehead" spots. The Mexican lancehead rattlesnake's diet consists almost entirely of mammals. Males have a larger head than females and will eat larger prey as a result. The scientific name of this species "polystictus" refers to its pattern: "poly" = many, "sticto" = spotted.
Fun fact: The venom composition and feeding behavior between adult and juvenile Mexican lancehead rattlesnakes is different and changes with maturity! Adults of this species will frequently bite-and-release their rodent prey, and their venom is less toxic on average and causes more hemorrhaging. Juvenile Mexican lancehead rattlesnakes will often bite-and-hold their prey, and their venom is slightly more toxic, consisting of more neurotoxic characteristics.