Ecology

Snakes

Lizzy Ryan
Strawberry Hill Nature Preserve

(9/2020) Snakes. Those slithery serpents whom many cringe at the sight. Others, like myself, jump at the opportunity to see one. This article is for those out there that are not a fan of snakes. Hopefully, after reading this, you will have a newfound appreciation for these important creatures.

Here are some slithering facts about snakes:

"There are more than 3,000 species of snakes on the planet and they’re found everywhere except in Antarctica, Iceland, Ireland, Greenland, and New Zealand. About 600 species are venomous, and only about 200—seven percent—are able to kill or significantly wound a human (National Geographic)."

Snake have an awesome way of eating. If they are nonvenomous, they constrict their prey, meaning they strike and then squeeze their prey until it can no longer breathe. Then, they swallow it whole. Snakes can open their mouths three times the size of their head! That is equivalent to us swallowing a watermelon in one bite! Contrary to popular belief, they cannot unhinge their jaws to do this. They actually have really stretchy ligaments in their mouths. In fact, their bottom jaw is in two pieces, connected together in the middle by another stretchy ligament. Their teeth are curved backward. This allows them to "walk" their prey into their mouths and down their throats.

Snakes also have a great sense of smell. When they flick their tongue in and out of their mouths, they are smelling. They have a special organ called the Jacobson’s organ (also known as the vomeronasal organ) that allows them to take in scents with their tongue. This organ is located just above the roof of the snakes’ mouth in the nasal cavity. Snakes have "heat pits" which allows them to sense heat of warm-blooded creatures. These heat pits are located along their jaw.

Snakes do not have external ears. They "hear" by sensing vibrations in the earth.

You may often find snake skins in your sheds or log piles. Snakes shed their skin as they grow and to get rid of any parasites. It does not hurt them to shed, and in fact, when I’ve watched our snakes shed, they look relieved. They will rub on any rough object they find to help them get the old skin off.

Snakes comes in a variety of sizes. The largest snake in the world is the reticulated python growing to a whopping 30 feet. The smallest snake is the thread snake growing to about 3.9 inches.

Many think that all snakes lay eggs when in fact only 70% of snakes lay eggs. The rest bear live young. Snakes do not do any parenting. They lay the eggs/give birth and then leave the young to care for themselves.

I get lots of questions asking how to tell the difference between a venomous and a nonvenomous snake. One way is by the shape of their head. If they have a round/oval shaped head (much like the shape of your thumbnail) it is most likely a nonvenomous snake. If it has a triangular shaped head, it is most likely a venomous snake. Another way to tell is by the shape of their eyes. Nonvenomous snakes will have round pupils and venomous snake will have slitted pupils (like a cat).

There are 21 species of snakes in found in Pennsylvania and 27 in Maryland. There are two types of venomous snakes found in the area. They are the Northern Copperhead and Timber Rattlesnake. Both are pit vipers. They are called pit vipers because they have a heat seeking pit between each eye and nostril.

Copperheads are found in forests and fields in rock or log piles. Like their name suggests, copperheads are copper in color. The juveniles look just like the adults except they have a bright yellow tail.

The timber rattlesnake is often found in upland forests in rock outcroppings or log piles. They have two color phases- a light and a dark. They have a chevron like pattern on their bodies. The juveniles of the timber rattlesnake also look just like the adults.

Snakes are very important to our environment. Without snakes, there would be a severely high number of rodents around. The snakes that live in this area eat small rodents like mice, rats, rabbits, voles, moles, chipmunks and squirrels. They will also feed on eggs, birds, frogs and if the snakes are small enough, worms and insects.

One type of snake that is very common to this area is the black rat snake. Black rat snakes are known to be the longest snake in North America. They can reach over 7 feet long. They like to spend their time in trees. Black rat snakes lay between 5-30 eggs in early summer. Every summer we found many rat snakes at our house, usually in our straw bales or our shed. I have even found them a time or two in our chicken coop going after the eggs!

Another common snake is the garter snake. These are a smaller species of snake. They will feed primarily on worms, insects, and small amphibians. Garter snakes are also ovoviviparous, meaning they bear live young. Garter snakes are found in fields and forests.

If you encounter a snake in the wild, it’s best to leave it alone. You obviously would not want to get up close enough to it to see its eye and head shape to tell if it’s venomous. If you don’t bother the snake, they won’t bother you. Let them go about their daily business. After all, they are helping you out by eating the rodents!

At Strawberry Hill, we currently have 3 snakes that we use as Animal Ambassadors. We have Regina, a ball python, Cornelius, a corn snake, and Leche, a Pueblan milk snake. They each have their own personalities. Regina for instance, loves to look out the window and spend time outside in the sunshine.