Garter Snakes Are Reptiles With a Smile

Garter snakes are some of the best-known snakes.

But why are they called garter snakes?

Well, they look a lot like an old-fashioned piece of clothing by the same name. Before stretchy socks were created in the 1930s, people wore garters to keep socks from sliding down. These garters often had striped or checkered patterns.

So one story goes that when biologists were naming the snakes, they thought they looked like sock garters. Some people believe the name comes from a twist on the word “garden,” since garter snakes are often found in or near gardens.

THEY’VE GOT THE LOOK

Garter snakes belong to the genus Thamnophis (Greek for “bush snake”). They are found from southern Canada to Costa Rica and live in all of the lower 48 states. Most of the 37 species in this genus are named garter snakes, but there are two skinny ones called ribbon snakes and two in Mexico called mountain meadow snakes.

Most garter snakes have dark bodies (brown, black or gray) with light stripes from head to tail. They can also have a checkered pattern or a combination of the two. One even has side-to-side stripes in a ladder pattern. Typically, one bold stripe goes down the spine with two other stripes, one on each side of the body, but the checkered patterns vary a lot — from very pronounced to absent (which goes for the stripes too).

Stripe and checker colors also vary a lot, from green, blue and white to yellow, red and orange. Unlike venomous snakes, garters have a rounded head (not triangular), plus large, round eyes; they also seem to have a permanent smile. Many have dark vertical chin stripes under the mouth, and they often have a bicolored tongue — red or orange with a black tip.

WHAT’S FOR DINNER?

Garter snakes are considered nonvenomous and harmless to humans. However, some produce a minor venom or toxin in their saliva that can paralyze earthworms and other small prey. They also eat slugs, snails, small amphibians, insects, and small rodents and birds on occasion. A few species live mostly in water and hunt for fish.

Many are habitat specialists and have small ranges. The most abundant species, however, is the common garter snake, which is found in much of the U.S. As there are 12 subspecies of common garter snake, they can look totally different depending on where you see them.

Most garter snakes prefer woodlands or grassy areas. But some are highly aquatic, and a few are desert dwellers. They are diurnal, meaning they’re active during the day.

BIG WINTER SLEEPOVER

Being “cold-blooded” makes it hard for snakes to move quickly or find prey when temperatures drop. Many species hibernate over the winter, and common garter snakes den together underground to share body warmth. Winter dens may have thousands or even tens of thousands of snakes! In fact, common garter snakes form the biggest gathering of snakes in the world.

Large numbers also come together during mating season, which can take place right before or after hibernation. The rest of the time, garter snakes are typically solitary, but scientists recently discovered that garter snakes also like to hang out with close “friends.” Social groups typically include three or four snakes but may number almost 50.

Females give birth to live young (the eggs develop inside her). She may have anywhere from five to 80 young, depending on the species. Neither she nor the male provide any parental care. The young are born ready to fend for themselves. With most species, the young are about 5 to 9 inches long and will reach anywhere from 2 to 4 feet when adults.

DO YOUR PART

While most species have stable numbers, at least seven have declining populations. One that is considered threatened is the giant garter snake (the largest species), which reaches up to 65 inches in length. That’s almost 5½ feet! Found in California’s Central Valley, it was named the official snake of the state this past April.

The other threatened species is the narrowhead garter snake, which lives only in Arizona, New Mexico and northern Mexico. Two subspecies of otherwise stable garter snake species are also endangered or threatened.

Habitat loss is a major problem for at-risk garter snakes. Getting run over by vehicles is another. Do your part to help these “smiling,” beneficial reptiles by educating others about the great job garter snakes do controlling yard and garden pests.

3 Fast Facts

1. Garter snakes can live more than 10 years in the wild.

2. The Narcisse Snake Dens in Manitoba, Canada, provide winter shelter for about 75,000 red-sided garter snakes. Visitors to this wildlife management area are allowed to pick them up if they want to!

3. Don’t confuse North American Garter Snakes with African Garter Snakes! African species are unrelated and are venomous, belonging to a family more closely related to cobras and mambas.

Bats and birds are their specialties, but wildlife biologists Selena Birgit Kiser and Mark Kiser love all species of critters. Both have worked for the State of Florida and previously worked for Bat Conservation International on such programs as the Great Florida Birding and Wildlife Trail and the North American Bat House Research Project.