The Timber Rattlesnake (Crotalus horridus) is endangered in Indiana due to habitat destruction and fragmentation as well as human persecution. If it becomes extinct in the Big Woods, rodent populations could grow. More importantly, its extinction would reduce diversity and serve as a warning that overall forest health is declining. The following piece was written by Zach Walker, an expert on reptiles and amphibians.
As winter warms to spring, reptiles and amphibians begin to emerge from hibernation. Spring peepers and chorus frogs fill the night with their song, salamanders begin to creep toward small breeding ponds and snakes begin to emerge from their dens. As the earth warms, timber rattlesnakes begin to stir.
The timber rattlesnake is typically brownish to yellow in color with a rust colored band running down its back from head to tail. Additionally, it has 18-25 cross bands, or chevrons, which run across the rusty band. These colors provide camouflage ideal for the forest floor, allowing the rattlesnake to lie hidden from both predator and prey. Typically, timber rattlesnakes remain motionless when approached in hopes that they will not be seen. When encountered, this timid creature usually attempts to flee from aggressors rather than strike.
After the timber rattlesnake emerges from its den, it remains in the immediate area basking for a few days before moving off (sometimes up to two miles away) to its summer range where it begins to search for food and shelter. They prefer areas near fallen logs and thick ground vegetation, which provide cover and a source of food. Timber rattlesnakes eat small rodents, ranging from mice to squirrels, but have been witnessed to consume turkey poults, grouse and other warm-blooded animals. A timber rattlesnake often forages beside a fallen tree where it has smelled its prey. It then waits, with its head resting on the log, for the perfect moment to strike. As its prey runs along the log, the snake strikes, then waits for the venom to do its work. After the prey dies, the snake tracks it by its smell and swallows it head first. Being cold blooded, rattlesnakes move to warm areas after eating for digestion and basking.
August brings the breeding season. During this time, male snakes travel up to two miles looking for receptive females. Once a male finds a mate, he keeps other males away for a few days until they mate. Remarkably, even though mating occurs in the late summer, females do not immediately fertilize their eggs. The following spring, the female fertilizes her eggs internally and incubates them within her body for the entire summer. During this pregnancy the female does not eat and loses considerable weight. In the early fall, she gives birth to 10-12 live neonates (baby snakes) and remains with the young for about a week.
At birth, timber rattlesnakes have venom and are typically slate gray in color, with black chevrons and a pinkish white belly. Born with one button on their rattle, they typically shed their skins (and gain another button) the second week after birth. After shedding, the 7 to 9 inch juvenile snakes need to find a den in which to hibernate. To do this, they track scent trails left by adult snakes to nearby dens, which become their winter home for years to come.
In the fall, adult timber rattlesnakes usually try to get another meal before moving back to their dens. They may share dens with many snakes – not just other rattlesnakes, but also garter snakes, black rat snakes, copperheads and/or black racers. As winter approaches, the snakes move back underground, waiting for the warmth of spring.
There are 35 species of snakes in Indiana. Four of them are venomous. Nine are endangered.
• Venomous and endangered
• Live up to 25 years
• Number of buttons on rattle is how many times skin has been shed; usually more than once per year
• Females give birth only once in 2 to 5 years
• Less than 15% of young survive past 3 years of life