The Rat Snake

Example of Natural Selection by Bede Adam

Introduction to the Rat Snake

The common rat snake is medium-sized, averaging 42 to 72 inches (106.7 to 183 cm) in length.

Rat snakes comprise of a number of different species, all having similar diets to one another and being excellent climbers. They kill by crushing their prey leading to suffocation. All the species have the same reaction to danger or threats, remaining motionless when startled and avoiding confrontation whenever possible.
The rat snake may bite, but only if threatened. They are a non-venomous type of snake.
Rat snakes are well known to be rodent eaters, however the adult diet may also consist of mice, chipmunks and moles. As infant snakes, they tend to eat small lizards, baby mice and the occasional frog.

Evolution of the Rat snake

Rat snakes come in a wide variety of colours; from yellow striped to black, orange and to greenish colours. This is because rat snakes are found all over the Eastern and Midwestern parts of the United States, and have to survive in all types of climates and terrain.
These types of snakes can be common in urban areas, but they can also be found in forested areas, mountain or coastal niches. As a result of this, the rat snakes have had to adapt to their environmental needs in an attempt to avoid detection from their predators.

Examples of the rat snake

The effect of evolution on the rat snake

Rat snakes have evolved to have different coloured scales across the range of the species, depending on the envirnonment in which they live. (add examples) This camouflage helps them to avoid threats from their predators and assists them to hunt more effectively.

A few subspecies of the rat snake tend to be more aggressive. An example of this is the Texas rat snake and the black rat snake. They tend to be very snappy, while the yellow rat snake is more passive.
When threatened, the rat snake will coil up its body and vibrate their tails on dead leaves which will stimulate a rattle. if continued to be provoked, the rat snake will strike.
Another defensive mechanism is that the rat snakes produce a putrid-smelling musk which is then released on their predator. They spread this musk around with their tail.

Texas Rat Snake 2011
Mating Rat Snakes