If you’ve stumbled upon a clutch of eggs and are wondering if they belong to a garter snake, you’ve come to the right place. Garter snakes are one of the most common snakes found across North America, so it’s not unusual to encounter their eggs.

In this comprehensive guide, we’ll cover everything you need to know about identifying garter snake eggs.

If you’re short on time, here’s a quick answer to your question: Garter snake eggs are oblong in shape, about 1-1.5 inches long, and have a leathery, flexible shell that is usually whitish or pale yellowish in color.

Read on as we dive into details about garter snake egg size, shape, shell texture and color. We’ll also discuss where they lay their eggs, typical clutch size, incubation period and what hatchlings look like.

With helpful photos and information on lookalike eggs from other species, you’ll be able to confidently identify garter snake eggs.

Typical Size and Shape of Garter Snake Eggs

Oblong and Around 1-1.5 Inches Long

Garter snake eggs have an oblong, oval shape and are generally 1-1.5 inches (2.5-3.8 cm) long with a width of around 0.75 inches (1.9 cm). This slender, capsule-like shape allows the flexible eggs to pass through the female snake’s oviduct for laying.

Compared to spherical eggs, the streamlined oblong shape takes up less space inside the mother and allows her to produce a larger clutch size of 16-40 eggs on average.

Larger and More Slender Than Chicken Eggs

While variable based on species, garter snake eggs are visibly larger yet more slender and elongated than the rounded chicken eggs commonly found in grocery stores. For example, common garter snake (Thamnophis sirtalis) eggs may reach 1.5 inches (3.8 cm) in length but only 0.75 inches (1 cm) in diameter, giving them a more narrow, capsule-like silhouette compared to a chicken egg.

The eggs’ leathery outer shell also tends to be more flexible and compliant than a hard chicken egg shell.

Shell Texture and Color

Leathery and Flexible

The shells of garter snake eggs have a leathery, flexible texture that allows them to stretch as the embryos inside grow. This flexibility helps prevent the shells from cracking or breaking as the young snakes develop.

The leathery texture comes from the makeup of the shell, which contains tough, fibrous proteins interlaced with softer membranes. This gives the shell durability while still allowing for expansion.

When newly laid, garter snake eggs feel parchment-like. But as moisture is absorbed from the environment, the shells become more pliable and elastic. The leathery shells also protect the eggs from drying out while allowing oxygen to pass through tiny pores for respiration.

Compared to bird eggs, which have hard, calcified shells, the supple, leathery shells of reptile eggs bend rather than crack under pressure. This leathery texture enables the eggs to withstand the weight of the mother snake without damage as she basks on top of her eggs to warm them.

Whitish or Pale Yellow

Garter snake eggs are generally whitish or pale yellow in color when first laid. The color comes from the calcareous outer covering of the shell, which often has a chalky, white appearance. Underneath this outer layer, the egg shell tends to have a pale yellowish or straw-like hue from the fibrous proteins it contains.

The pale coloration helps camouflage the eggs in their natural habitat, such as among dirt, leaves, vegetation, or other natural debris. This protects the vulnerable eggs and embryos from visual predators.

In some species, like the North American common garter snake, the eggs may take on a more pinkish or orangish tint over time as the embryos inside grow and develop. The pinkish color results from the increasing vascularization and blood circulation of the embryo that becomes visible through the translucent shell.

So while newly laid garter snake eggs tend to be more whitish, maturation over the incubation period often causes their shells to take on different diluted shades of yellow, orange, pink, or brown. But overall, their muted, light coloration serves as effective natural camouflage in the wild.

Egg-Laying Habits and Typical Clutch Size

Lay Eggs in Rotting Logs, Compost Piles, etc.

Garter snakes are truly resourceful when it comes to finding a spot to lay their eggs. They often deposit their clutches in rotting logs, compost piles, sawdust piles, and other dark, warm, humid places. The decomposition happening in these sites produces heat that incubates the eggs.

Garter snake moms don’t stick around to care for their young, so finding the right incubation spot is crucial!

Some specific egg-laying sites that have been observed include:

  • Under boards, metal sheets, or other debris left on the ground
  • In rotting logs or stumps
  • Among wood chips or sawdust piles
  • In compost or manure piles
  • In greenhouses or hot houses
  • In a pile of wet leaves or grass clippings

Garter snakes have also been known to lay their eggs in termite mounds, which provide warmth and protection. The snakes’ll crawl down into the depths of the mound to deposit the eggs before abandoning them. What great moms, right? 😆

Average Clutch Size is 10-40 Eggs

The typical garter snake clutch contains 10-40 eggs, though the common garter snake averages around 20-30. The clutch size depends on several factors:

  • Species – Some garter snake species, like the checkered garter snake, tend to have smaller clutches.
  • Age of the female – Older, larger females tend to lay more eggs.
  • Geographic location – Snakes in certain regions may lay smaller clutches.
  • Availability of resources – If food was scarce, clutch may be smaller.

Garter snakes begin breeding at around 2-3 years old. As they mature, their annual clutch size often increases. The eggs are fertilized internally by the male before laying.

Here’s a breakdown of typical clutch sizes by garter snake species:

Species Typical Clutch Size
Common garter snake 20-30 eggs
Western terrestrial garter snake 10-15 eggs
Checkered garter snake 4-10 eggs
Red-sided garter snake 15-20 eggs

The eggs are oblong in shape, measuring 1-1.5 inches long, with flexible, leathery shells. After being laid, they’ll incubate for anywhere from 4-12 weeks before hatching, depending on the temperature.

Incubation Period and Hatchlings

45-65 Days to Hatch

Garter snake eggs have an incubation period that lasts between 45-65 days on average before hatching, according to reptile care websites like The Spruce Pets. The incubation duration can vary depending on factors like the species of garter snake, climate and temperature conditions, and whether the eggs are incubated naturally by the mother or artificially in an incubator.

For example, common garter snakes (Thamnophis sirtalis) tend to hatch within 8-10 weeks when incubated between 75-85°F. Western terrestrial garter snakes (Thamnophis elegans) may emerge a little sooner at 6-8 weeks if kept at 78-80°F in an incubator.

The warmer the incubation temperature, the quicker the hatch time up to a point. Much above 85°F can have detrimental effects.

Babies are 6-8 Inches Long

According to ReptiFiles.com and other sources, newly hatched garter snakes measure approximately 6-8 inches long. Their size can vary a bit depend on subspecies and incubation factors, but most seem to emerge from their eggs in the half-foot range lengthwise.

These little snakes are essentially miniature versions of the adults at birth.

Garter hatchlings are fully developed and ready to hunt for food right away. Their first meals often consist of small frogs, toads, slugs, worms, and insects which are easy for their tiny bodies to swallow.

Survival can be challenging compared to the high egg numbers of most garter broods, but the snakes grow rapidly if supplied proper housing and nourishment by owners.

Differences From Other Snake Egg Species

Smaller and More Slender Than Racer Eggs

Garter snake eggs tend to be more petite and elongated compared to the eggs laid by racer snakes (Coluber constrictor). According to herpetological research, the average garter snake egg measures around 2-3 cm in length and 1-1.5 cm in width.

Conversely, racer snake eggs are typically 3.5-5 cm long and 2-2.5 cm wide. The slender shape and diminutive size of garter snake eggs allows them to be laid in greater quantities and tucked into small, concealed locations more easily.

These morphological differences can be attributed to the fact that racers are larger snakes, with adult females reaching up to 7 feet in length. Garter snakes rarely exceed 3 feet as adults. The larger racer snake lays bigger eggs to accommodate the development of its larger babies.

The smaller garter snake has less demand for resources during embryonic growth and thus produces smaller eggs. This aligns with Haldane’s rule, which states that differences in size between species correlates strongly with differences in egg size.

Darker Than Milk Snake Eggs

Another key distinguishing feature of garter snake eggs is their dark gray, olive brown, or blackish coloration. This is much darker than the pearly white or yellowish eggs laid by milk snakes (Lampropeltis triangulum).

The darker egg coloration likely serves as camouflage to keep the vulnerable eggs hidden from predators when laid in damp, earthy sites. The lighter egg color of milk snakes may help reflect heat to keep the embryos warm, as milk snakes originate from more exposed nesting sites.

According to field observations compiled on Reptiles Magazine, common garter snakes (Thamnophis sirtalis) lay about 10-40 eggs per clutch, whereas milk snakes only lay 4-10 larger eggs. Again, this aligns with ecological theory about an evolutionary tradeoff between egg size and number.

Garter snakes produce more numerous, smaller eggs as a reproductive strategy. Their dark coloration allows them to be safely concealed in large clusters.


Now that you know what to look for, you can confidently identify garter snake eggs if you come across them in the garden or elsewhere outdoors. Key identification points include the oblong shape, leathery texture, size of 1-1.5 inches, and pale whitish-yellow color.

While the eggs may resemble those of other species, the details in this guide will help distinguish garter snake eggs.

We’ve covered everything from average clutch size to incubation period to how the hatchlings look and behave. Armed with this knowledge, you can appreciate the wonder of garter snakes reproducing right in your own backyard.

If you have any other questions about garter snake eggs, feel free to refer back to this comprehensive guide.

Similar Posts