Have you ever wondered how a snake slithers up a tree, captures prey far larger than the size of its jaw, or sheds all of its skin? Not many people give these reptiles a second thought. But Dr. Harvey Lillywhite, herpetologist and Professor of Biology at the University of Florida, gives them a great deal of thought. In How Snakes Work: Structure, Function and Behavior of the World’s Snakes, he covers all of the intricacies that make up snakes across the globe—from the more-or-less harmless creatures we find slithering in our backyards to the dangerously venomous reptiles we hope to never encounter in the desert. The snake slideshow below, with facts from the book and snakes photographed by Dr. Lillywhite, demonstrates how much can be learned about these fascinating reptiles including their exceptional anatomy, senses, and movements.
How have snakes evolved?
Over time, different species of snakes have evolved with very particular adaptations that aid in their survival. This image of a Western Hognose Snake highlights the species’ snout—which helps these snakes burrow into the ground.
How do snakes eat?
One of the most gripping features of a snake is its ability to capture and swallow prey without the aid of any appendages. The extreme mobility of a snake’s jaw allows this reptile to swallow food far larger than the size of its head.
How does snakes' venom work?
Venomous snakes deliver their venom via fangs. This venom can affect prey in a variety of ways, depending on the molecular composition of the venom. Many venoms damage the cell membranes of the victim’s cells, which helps this toxic substance spread quicker throughout the victim’s body. Some venoms can even bind to the proteins involved in neurotransmission of signals between cells, which in turn paralyzes the prey and inhibits its ability to run away.
How do snakes digest food?
Snakes have a lower rate of metabolism than do mammals, and they require less food. Snakes are also intermittent feeders, and some captive snakes have been documented to fast for more than one whole year between meals. Because snakes only eat periodically, they do not waste energy on maintaining their digestive organs’ function at all times. Snakes have developed the means to up-regulate digestive enzyme production and intestine activity only when food has been consumed. Between feedings, some snakes allow their digestive tract to atrophy.
How do snakes slither?
The side to side movement that we non-snake experts have come to call slithering is referred to in scientific terms at “horizontal undulatory progression.” Put simply, snakes alternate muscle contractions in a wavelike pattern in order to propel themselves over water or through a variety of terrestrial landscapes. These organized contractions exemplify the development of precise neuron signaling within the bodies of snakes.
How do snakes stay warm?
Snakes are ectotherms, which means that their bodies depend on heat exchanges with their surrounding environment. Heat passes from the environment to the snake’s body through the snake’s scales. Factors such as the coloration and arrangement of these scales, and the position and posture of the body, will influence the rate at which this heat is ultimately transferred to the snake’s body.
How do snakes breathe?
Snakes are no exception when it comes to species that require a steady intake of oxygen to survive. Snakes breathe in air through nostrils or nasal openings. A snake’s tongue is not involved in this intake of oxygen, and is used instead primarily for sensory functions.
How do snakes always keep their eyes open?
Have you ever noticed that snakes’ eyes never appear to close? This is because snakes do not possess eyelids. As such, their cornea requires a special coating called a spectacle or brille. This covering is actually a clear extension of the snake’s skin.
How do snakes hear approaching predators?
Despite the fact that snakes can make sound—whether that be hissing noises or the rattling of a tail—hearing in snakes is limited. Snakes do not possess any external ears, and instead they rely on conduction of sound or ground vibrations through tissues of the head and body. Snakes can hear sound over a limited range of frequencies compared to humans, but detection of airborne or ground-borne vibrations is an important means by which they stay alert and aware of their surroundings.
How do snakes reproduce?
Though most snakes appear to look the same to an un-trained eye, snakes can be differentiated between male and female. This is an important distinction to make when it comes to snake reproduction. Like other reptiles, fertilization in snakes is a process that occurs internally within females during copulation with a male partner. Mating and fertilization, however, do not have to occur at the same time, as females can store male sperm—often times from multiple different mates—for several months or years. This adaptation allows females to lay eggs at the most optimum time and with sperm from the most optimum mate, thus increasing the chances of her offspring’s survival.
How do I learn more about snakes?
These slides only provide a glimpse of the astounding features that make up snakes. To learn more, pick up your copy of “How Snakes Work: Structure, Function and Behavior of the World’s Snakes.”
Image credit: All of the images used in this slideshow were photographed by Dr. Harvey Lillywhite.
Feature Image Credit: Dr. Harvey Lillywhite.