We often think of this time of year—call it “Indian summer” if you will—as the time when plants and animals are winding down as colder weather is approaching. Bird breeding has wound down, and maple and certain other trees are already starting to change colors. 

There are a few animals, however, that produce young during this time of year. A few of these animals are of the slithery type.

In late August to early September, baby timber rattlesnakes (neonates) make their first appearance in the region, but the reproductive process actually started a year ago, during mid-summer, when mating took place. Females began the formation of eggs last summer, and those females that mated stored sperm through the winter for use this past spring when they emerged from hibernation. The eggs were ovulated with the stored sperm. 

The whole process, from mating to birth, averages around 13 months. Female rattlesnakes only become gravid every two to three years.

Gravid females have spent the summer at rocky, open gestation sites basking in the sun to warm up their bodies and aid embryo development. When born, the little rattlesnakes appear as miniature, foot-long versions of an adult; however, they are battleship gray in color and do not show a black or yellow phase yet. They shed shortly after birth and develop a single rattle segment, or button.

After two weeks or so, the babies disperse and will eventually follow scent tracks made by their mother to make their way to their hibernaculum to spend the winter with other rattlesnakes, and perhaps other species of snakes that share the den. Timber rattlesnakes start making their way to their dens next month.

Neonate rattlesnakes are born with functioning hollow fangs as well as venom; they are capable of biting animals or people. Like adult rattlesnakes, they will avoid confrontation when possible, but do not try to pick up a neonate rattlesnake if you see one. Neonates will spend three to four weeks after birth before they enter the den. They will not eat during this brief time, but will emerge next spring and start foraging on their own as young-of-year timber rattlesnakes.