Snakes are creatures that most people either love or loathe. Northeast Iowa has its fair share of the slithery critters but for the last thirty years, one species has been in serious decline with numbers reduced by over 50%. Timber rattlesnakes are not listed as an endangered or threatened species in Northeast Iowa because there is not enough information available on their numbers or distribution although they have been protected across their Iowa range since 2002, but numbers are yet to show signs of recovery.
Timber rattlers prefer rocky slopes for their dens but development and construction work across their habitat is a major threat. As if that were not enough, cedars and other shrubs have begun to encroach on goat prairies as a result of fire suppression. This has discouraged both the snakes and the small mammals and insects on which they prey. The snakes are also poached for the exotic pet trade and pesticides and herbicides reduce the quantity of prey available to them.
People have a natural and often misplaced fear of snakes which leads to many unnecessary killings. Although the snakes are venomous and could in theory kill a human being, the species is not aggressive and generally goes out of its way to avoid encounters with people. The snake’s bite is in fact dry – no venom is injected – and would only be used in self-defence. If you leave the snake alone and don’t try to pick it up or otherwise interfere with it; you have nothing to fear.
Timber rattlesnakes are members of the pit viper family so named for the facial pits situated on either side of the snake’s head. The pits are heat sensitive and it is this that enables the snake to detect warm-blooded prey in the dark. The snake has two hollow fangs situated in the front of its mouth and these are connected to venom glands.
The snakes have very poor eyesight and are only able to detect movement at relatively close proximity. To compensate they have a very highly developed sense of smell. The animal’s tongue collects scent particles in the air which the brain interprets. Snakes do not have ears but can detect vibrations through the ground. This enables them to gauge the size of passing animals; their proximity and direction. The rattle in the snake’s tail is used as a warning signal which should be heeded should you come across one.
In the wintertime, timber rattlesnakes hibernate in underground dens in rocky areas. They share their den space with other rattlers and also with snakes of other species. When the weather warms up in mid-April, the snakes emerge from their dens and warm themselves up by basking in the sun.
Later in the spring, the snakes migrate in a seasonal cycle which takes them anything from 1.3 to 2.5 miles from the den. Males and females meet during this migration and breed, the snakes then returning to the den by autumn in time for their winter hibernation.
What to do if you encounter a timber rattlesnake
It’s possible that you might come across a timber rattlesnake if you’re out hiking in the northeast Iowa wilds. A snake will usually detect your approach by sensing the vibrations of your feet through the ground as you walk and will be long gone before you get too close. If you disturb a sleeping snake, it may deploy its first line of defence - its rattle. Back away slowly and calmly. Don’t make sudden movements as this may agitate the snake.
Don’t be tempted to get down really close to photograph the snake. This may be perceived as threatening and the snake may feel it has no option but to bite. If you are bitten, try to remain calm; regulate your breathing and keep still to prevent your heart rate rising which will increase your pulse and pump any venom injected around your system more quickly. It’s very unlikely that you will have received enough venom to prove fatal but you must seek medical assistance immediately.
*Image courtesy Flickr creative commons.