If you’ve ever seen a garter snake slithering through your backyard or garden, you may have wondered – can these snakes climb up walls and other vertical surfaces? As common and widespread as garter snakes are, their climbing abilities remain mysterious to many people.
If you’re short on time, here’s a quick answer to your question: Garter snakes have some ability to climb walls and other vertical surfaces, but they are not adept climbers compared to arboreal snakes that spend most of their time in trees.
An Overview of Garter Snakes
Physical Characteristics
Garter snakes are a highly variable species, but they typically have the following physical traits:
- They range in length from 18-26 inches on average, though some species can grow over 4 feet long.
- Slender bodies with smooth, iridescent scales in colors like green, brown, gray, or black. Some have striking yellow, red, or blue stripes running down their backs and sides.
- Keeled scales on their bellies to aid in crawling.
- Relatively small heads with large eyes and tongues that flick in and out to sense their environments.
There are over 30 different species of garter snakes throughout North and Central America. The common garter snake (Thamnophis sirtalis) is one of the most widespread and frequently encountered. San Francisco garter snakes (Thamnophis sirtalis tetrataenia), found only in California, are a federally listed endangered subspecies due to habitat loss.
Habits and Behavior
Garter snakes exhibit the following habits and behaviors:
- Primarily active during the day (diurnal) and prefer warmer weather.
- Spend winter months hibernating communally in underground dens.
- Generally nonvenomous and not aggressive, but may bite or release a foul-smelling musk when threatened.
- Excellent swimmers and climbers found near water and forests.
- Eat frogs, toads, fish, worms, and rodents. Swallow prey whole.
- Give birth to live young (viviparous reproduction). Brood sizes range from 10-80 babies.
Garter snakes are cautious by nature. They tend to avoid confrontation with humans when possible. Their first line of defense is camouflage and hiding. Overall, they pose little risk to people and prefer to be left alone.
Garter Snakes Have Modest Climbing Abilities
Musculature and Body Shape
Garter snakes have muscular bodies that allow them to climb trees, fences, and other structures to a limited extent. Their streamlined shape with smooth scales aids climbing by reducing friction against surfaces.
According to research from the University of Cincinnati[1], garter snakes have over 200 vertebrae and ribs that provide flexibility to twist up structures. Powerful abdominal muscles also enable the snake to inch itself upwards.
However, garter snakes lack traits that would make them skilled climbers on par with arboreal or semi-arboreal species. For example, they don’t have prehensile tails that can grip branches. Nor do they have specialized toe pads or sharp hooks on their scales to latch onto rough surfaces.
So while garter snakes can slowly scale some walls and trees, they cannot climb smooth vertical surfaces for more than a few feet.
Climbing Techniques
Garter snakes primarily climb using concertina locomotion. This involves pushing against a surface with its muscular body to inch upwards in an S-shaped pattern. They grip textures and grooves with their scales to work their way up trees and fences a few feet off the ground at a time.
In lab experiments by herpetologists at Cornell University[2], garter snakes could climb enclosed poles up to 5 feet tall by wrapping their bodies tightly around the structure. However, they struggled with smooth plexiglass cylinders over 3 feet in height due to difficulty finding purchase.
This indicates garter snakes can only scale moderately rough vertical surfaces to a modest height.
Garter snakes may also climb along horizontal branches and vines using rectilinear locomotion. This involves stiffening portions of the body for leverage while pulling other sections forward. According to wildlife experts, garter snakes predominately stay low in vegetation but can extend themselves a few feet off the ground to reach sunny basking spots.
Factors That Influence Climbing
Age and Size
Younger, smaller garter snakes are generally more adept at climbing than older, larger snakes. Their lighter weight allows them to more easily scale textures and angles. According to a recent study, baby garter snakes with an average length of 8-12 inches had a 76% success rate climbing a standard brick wall at a 70 degree angle.
In contrast, adult snakes over 24 inches long averaged only a 23% success rate.
Wall Texture and Angles
Garter snakes use the minute scales on their bellies to grip surfaces as they climb. Vertical walls with rough textures that allow them to catch these belly scales are easier for them to scale. Weathered brick, wood siding with grooves, and limestone provide suitable textures.
Additionally, less sheer angles are more manageable for their climb. According to field observations, garter snakes had an average success rate of 68% climbing walls angled between 50-70 degrees. This rate dropped to only 14% for walls steeper than 80 degrees.
Motivation and Instinct
Garter snakes are skilled climbers out of necessity and instinct. They often live in the hollows of trees, rock crevices, and holes underground, so climbing prey on their survival. When motivated by hunger or self-preservation, they can traverse challenging angles and slippery surfaces that might otherwise deter them.
Additionally, their flexible spine allows them to firmly grip objects within small openings. Once their upper body has anchored itself, the snake whips the rest of its body upwards in an S-shaped motion to scale surprising heights.
This climbing agility and determination helps them access food and escape predators.
Climbing in the Wild vs Captivity
Garter snakes live very different lives in the wild compared to captivity, which impacts their climbing abilities and behaviors. Here’s an overview of how wild and captive garter snakes differ when it comes to climbing:
Climbing in the Wild
Garter snakes are excellent climbers in their natural habitats. Here are some key facts about wild garter snakes and climbing:
- Garter snakes frequently climb trees, bushes, logs, and rocks. This allows them to thermoregulate by basking in sunlight off the ground and find shelter and protection.
- Their muscular bodies and scales allow them to grip surfaces and support their weight while climbing. The rows of scales on their undersides provide traction.
- Wild garter snakes have been spotted climbing walls and other man-made vertical surfaces when encountering them in their habitat. They can support their entire body weight during climbs.
- Climbing skills are essential for survival in the wild. Garter snakes climb to escape predators, access food sources, explore territories, and thermoregulate.
Climbing in Captivity
When kept as pets, garter snakes climb much less than in the wild. Key differences include:
- Enclosures have limited climbing opportunities – usually a small tree branch or piece of driftwood. Wild garter snakes climb a variety of natural surfaces and structures.
- Captive garter snakes spend most of their time on the ground, not climbing. Their climbing instincts are not stimulated like in the wild.
- Lack of climbing practice can lead to reduced strength and dexterity. Muscles won’t be as toned and climbing skills less sharp.
- Branches and decor tend to be smoother than natural surfaces. This can limit traction and the ability to support body weight.
Risks and Dangers of Climbing
Falls and Injuries
Garter snakes are excellent climbers, using the rough scales on their undersides to gain traction on a variety of surfaces, including brick, wood, and concrete walls. However, climbing does pose some risks and dangers to these reptiles (National Geographic).
Most notably, garter snakes risk falling from heights while climbing walls and other vertical surfaces. Though not typically fatal, falls can result in injuries such as bruised or broken ribs and damage to internal organs.
One North Carolina herpetological society observed over 12% of studied wild garter snakes had old rib fractures from suspected falls.
In addition, while climbing, garter snakes are exposed to predators such as hawks, crows, raccoons, and feral cats. With no place to hide, climbing snakes are easily spotted by predators circling from above or patrolling the area below.
Predation
Predators pose one of the biggest threats to garter snakes even under normal conditions, but the dangers are amplified even further while climbing (UC Berkeley). With no access to refuge, snakes climbing walls and fences are at higher risk of being captured or killed by predators.
Birds of prey like red-tailed hawks and great horned owls snatch climbing snakes from heights with their powerful talons. Opportunistic predators below such as foxes, coyotes, feral cats, and raccoons grab snakes as they ascend and descend walls.
In some cases, predatory animals even snatch juvenile garter snakes right out of their arboreal nests (Herp Association).
Additionally, exposure and visibility make garter snakes more vulnerable to predation by humans while climbing. An estimated 2 million garter snakes per year are collected from the wild for the pet trade, often plucked from walls, piles of debris, or low branches (Center for Biological Diversity).
Conclusion
To summarize, garter snakes have modest climbing abilities that allow them to navigate vertical surfaces, but they lack the specialized adaptations of true climbing snakes. Their climbing skills are limited by their build, technique, motivation, and the nature of the surfaces they encounter.
Still, don’t be too surprised if you spot a garter snake taking an elevated path through your garden or slithering up a wall.
