The Fieldston Science Bulletin

By: Meredith Metz

In early spring, as the sun chases away persisting frosts, birds, insects, and reptiles come back from their shelters. Snakes are among these animals, so be on the lookout for increasing activity. The best way to gain appreciation for them is to understand their behavior and how their bodies function. Ultimately, snakes are an underappreciated gem of the natural world. 

In temperate climates, reptiles and other cold-blooded animals have developed different ways to cope with winter weather. Snakes at this latitude start brumating, meaning they slow their breath and metabolism when the temperature drops consistently below 60 degrees Fahrenheit. Once the weather gets warm enough, they become more active and start eating again. Most snakes use constriction to incapacitate their food, but others use venom produced by salivary glands to paralyze or damage cardiovascular operations. Almost all snake species swallow their food whole, with few exceptions, but contrary to popular belief, they are not able to dislocate their jaws. Instead, their mandibles, the sides of the lower jaw, connect with ligaments that allow the jaw to expand laterally. All of these traits work together to allow snakes to swallow large prey.

To hunt, snakes use a variety of senses. Their primary sense is smell, felt primarily through the Jacobson’s organ. The forked tongue brings samples of the air to this organ, which is in the roof of the mouth, in order to recognize familiar molecules. The tongue’s divergence lets the snake identify the direction of the smell. This helps the snake locate prey, mates, and predators, especially while in darkness. Many snakes have heat pits that let them detect infrared radiation. When the pit’s membrane senses this radiation, it sends an electrical signal to the brain, which then processes it as an image. When there is enough light, snakes can also see in color. However, their eyes can only detect blue and green wavelengths, which is called dichromatic vision. Additionally, snakes hear less than we do because they do not have ear holes. Instead, vibrations travel from their jaw to their inner ear. 

In addition to having unique senses, snakes also possess distinctive anatomy. Their true body is a lot longer than most think. It actually ranges from 1-31% of their total length, with arboreal snakes having the longest and terrestrial ones possessing the shortest. Their body is outfitted with elongated organs protected by about 400 ribs. Another source of defense is scales, which not only act as shields but also as camouflage. They are dry, waxy, and made of keratin. They shed the outermost layer when needed to remove parasites or to grow. 

There’s a lot more to snakes than meets the eye. Their unique structures, senses, and behavior paved the way for other developments, ultimately creating an almost alien creature. 

Sources:

http://wildlifepreservation.ca/blog/how-snakes-overwinter/

https://daily.jstor.org/how-snakes-swallow/

https://naturemuseum.org/cas/blog/scale-it-back

https://www.britannica.com/animal/snake

Featured Image Source: Indianapolis Zoo