Timber rattlesnakes interact with many different kinds of animals and perform several important roles within their environment. Primarily, timber rattlesnakes are predatory animals, which means they prey upon other small animals and carry out specific mechanisms for capturing and acquiring their victims.  Being heterotrophic and unable to produce their own food, they are not at the bottom of the food web.  Instead, they feed on animals that consume other animals or they feed on animals that consume other types of organisms, such as plants.  They usually prefer to feed on small, warm-blooded mammals, which makes them great contributors to the control of rodent populations within the environment. Though timber rattlesnakes are not at the bottom of the food chain, they are also not at the top.  In fact, C. horridus is preyed upon and consumed by many other animals, such as coyotes, foxes, raccoons, opossums, cats (domesticated and feral), eagles, hawks, owls, turkeys, and even other snakes.  These snakes however, are much larger, like the king snake.  Unfortunately, timber rattlesnakes are also hunted and killed by humans for various reasons.  By acting as both a predator and prey, timber rattlesnakes play a major ecological role within their environment to help maintain the "balance of nature".

        During the winter months, when snakes of all types retreat back to their annual dens, timber rattlesnakes will often share a den with many other snakes. Some of these snakes are of the exact same species (meaning timber rattlesnakes), but a fair amount are also individuals of a different species.  Bull snakes, black snakes, garter snakes, copperheads, milk snakes and prairie ring-neck snakes, are just a few of the many other species that share a den with C. horridus.  Typically, there is very little interaction among the various species of snakes within the den unless they are related.  For this reason, timber rattlesnakes form a mutualistic type of relationship with these other snake species, in which they can both live and survive in the same area without causing harm to the other.
Copperhead snake                                        Bull snake                                                            Red milk snake




            Like all animals, C. horridus is a heterotroph, meaning it cannot produce its own food.  It must rely on other organisms to acquire the nutrients and energy its body needs in order to function.  C. horridus is a carnivorous predator that preys mainly upon small, warm-blooded mammals, such as chipmunks, voles, shrews, mice, ground squirrels, rabbits, weasels and rats.  They have been known to consume birds, bird eggs, insects, amphibians, and other reptiles, such as snakes, lizards and frogs, but this diet is far less common.  In order to capture its prey, C. horridus relies heavily on their sense of smell, taste and vibration.  This includes the use of many important sensory organs and structures, as well as one of their most notable attributes: their venomous fangs.              
            Since C. horridus is a pit viper, one of its most useful sensory organs is a pair of facial pits located on each side of the head.  Each pit, found midway between the eyes and the nostrils, contains several nerve endings that can sense body heat of warm blooded animals from several feet away. These heat-sensitive openings are important in allowing the rattlesnake to detect when a prey item is close enough to strike and what type of prey source is present.  After detecting a possible food source, timber rattlesnakes will lunge at their prey as soon as it comes enough.  Then, C. horridus will sink its large fangs into the body of the animal, paralyzing it almost instantly.  The fangs are long, hollow teeth located in the upper jaw and will fold back into the mouth when not in use.   The venom issued from these fangs form in glands behind the teeth in the upper jaw.  When the rattlesnake strikes, the muscles surrounding the poison glands contract, squeezing the venom out and into the victim.  Once bitten, the rattlesnake will let go, allowing the prey to withdraw and run away if it can.  Unfortunately, it only takes a matter of minutes for the venom to kick in, but the rattlesnake won't consume the animal until it is officially dead. Next, the rattlesnake will rapidly track down its prey by using a flickering motion of its tongue to detect the prey's scent.  By flicking the tongue in and out of the oral cavity, it can absorb molecules and chemicals in the air and associate them with animals present in the area, especially its prey. Besides having two nostrils for smell, timber rattlesnakes also possess a special sensory organ called Jacobson's organ that also aids in the detection of prey sources.  It is located on the roof of the mouth and works in sync with the tongue by filtering and identifying the molecules the tongue picks up from the air and ground.  Now the rattlesnake can finally consume its prey.  Unlike many other animals, which typically grind and chew their food with teeth as a a way of pre-digesting their food, C. horridus simply swallows its entire prey whole.  It doesn't leave a single crumb on its plate!  The rattlesnake will then retreat to a sunny basking site in order to raise its body temperature for proper digestion.  The optimal temperature for digestion is generally around 80-85 degrees Fahrenheit for maximum efficient digestion.         

        The first stage of digestion occurs when the body of the animal passes through the esophagus of the rattlesnake. The venom secreted by the fangs helps break down the food along with other digestive enzymes secreted by other organs of the digestive tract.  The esophagus of C. horridus is extremely long, almost half the length of its entire body, and creates peristaltic movements that propels the food down into the stomach where gastric juices are released to aid in breakdown.  The partially digested animal then enters the small intestine, which is a small narrow coil where nutrients are absorbed into the blood.  Reptiles, such as C. horridus, contain closed circulatory systems, meaning that the blood is confined in vessels that travel throughout the body, distributing nutrients and minerals as it flows.  One advantage that C. horridus has over other reptiles is that it contains more internal folds within its digestive tract.  This key feature creates a larger surface area for absorption, thus greater nutrient acquisition.  After passing through the large intestine, the content moves into the cloacae chamber, which is a structure that only reptiles usually have.  This cloaca is not only important for the excretion of wastes, but also for water retention which prevents the rattlesnake from becoming dehydrated.  One digestive cycle usually takes about four days to complete, however, the rate of digestion may vary depending on body temperature.     

Another dietary tactic that C. horridus uses to capture its prey is by laying motionless on the ground near a log or by resting its head on a log and waiting for an animal to approach.  Once the animal enters the log, vibrations through the log alert the snake that a possible meal is present.  The vibrations travel from the log into the center of the lower jaw and through the connecting skull bones of the rattlesnake.  These vibrations not only alert the rattlesnake of possible prey, but they also reveal information about the size of the animal.  The rattlesnake will then position itself appropriately in order to strike.  For this reason, timber rattlesnakes are often thought of as ambush predators: they conceal themselves extremely well and then attack once a prey source approaches.  It appears to be a very a successful method of predation.  C. horridus is diurnal during the spring and fall, meaning it is more active during the day than the night, but is nocturnal during the summer when the heat is overbearing.   The typical routine of C. horridus includes basking in the sun during the day to promote digestion and then foraging at night when food is abundant.

Back To Home Page

To learn some more Interesting Facts about this organism, click here