Eastern diamondbacks on the move near Stuart this September

Two eastern diamondback rattlesnakes (*Crotalus adamanteus*) have been logged around Stuart in the past two weeks, one north toward Jensen Beach on September 4 and one south near Port Salerno on August 30.¹ This is the largest venomous snake in North America, and the pine flatwoods and palmetto country along the Treasure Coast is the habitat it is built for.²

An adult runs three to six feet, thick-bodied, tan to gray, with a row of dark diamonds down the back, each one outlined in pale scales. A dark band crosses the eye toward the corner of the jaw, bordered above and below by light stripes. The rattle settles most questions: cottonmouths and banded water snakes have none, and the pygmy rattlesnake, which does, rarely reaches two feet.

In Florida this snake lives mainly on rabbits. It finds a rabbit run by scent, coils beside it, and waits, sometimes a week in the same coil. Heat-sensing pits between eye and nostril pick out a warm body in the dark, the strike reaches about two-thirds of its body length, and then it lets go and follows the scent trail to the dead animal. On an ordinary day it moves thirty feet or less.

Late summer into fall changes that. Mating season in Florida runs from August into the cooler months, and males give up the sit-and-wait routine to travel, tracking females by pheromone trail and wrestling other males in a ritualized contest the loser simply leaves. That travel carries them across roads and through yards, and it is when most of them die. Early September is the stretch of the year when a diamondback is most likely to be seen crossing open ground. Females mated now give birth six to seven months later, usually ten to fourteen live young, and a female breeds only every two or three years.

It does not dig. For shelter from cold and from fire it borrows gopher tortoise burrows, armadillo holes, stump holes and root channels, and rests in palmetto thickets between. Flatwoods naturally burn every one to four years; that fire keeps the palmetto low and the ground between the pines open, which is what the rabbits need and therefore what the snake needs. Left unburned much past that, the understory closes into gallberry and palmetto. Savannas Preserve State Park and Atlantic Ridge Preserve State Park, both managed for biodiversity, are the large tracts of that fire-kept flatwoods in this corridor.³

Florida holds roughly half of what remains of this snake's range, and the state's own status assessment records it as gone from some urbanized parts of the southeastern peninsula, naming the loss of gopher tortoise burrows among the causes.⁴ iNaturalist flags the species as threatened; it carries no federal listing.⁵ Anyone who meets one on a trail this month can give it the room it wants. It is a patient animal, and it was almost certainly there first.