15 Interesting Facts About Wood Frogs

Wood Frogs are the only frog species that can live in the far northern regions of Canada and Alaska, where it’s too cold for other species to survive the winters. They have earned their name because they blend into wooded environments. In this article we put together a list of 15 or so interesting facts about wood frogs. Follow along as we learn more about these fascinating amphibians.

15 Facts about Wood Frogs

Wood frogs have several color variations to camouflage into leaf debris in wooded areas. They’re usually brown, red, gray, green, or variants of those colors. Wood frogs range in size from 1.5 to 3.25 inches. Like most frogs, females are significantly larger than males. Check out this list of 15 facts about these interesting amphibians!

1. They Live Further North Than Any Other Amphibian

Wood frogs are the only frogs native to far northern parts of Alaska and Canada. Living so far north, they endure some of the most extreme temperatures of any amphibian or reptile.

These frogs have adapted to survive the harsh winter conditions closer to the Arctic Circle. We will talk more later about how they can live through freezing temperatures.

2. It’s The Official State Amphibian For New York

The State of New York did not have an official amphibian for a long time. In 2018, the state assembly introduced a bill to make the wood frog New York’s official state amphibian.

This was done in part because a 13-year-old student wrote a letter in 2013 to a senator. The wood frog was proposed for its resilience and adaptability, traits that resonate with New York’s diverse and rugged landscapes. 

3. They Freeze During Winter

Wood frogs don’t just hibernate through the winter, they literally freeze and then thaw again in spring! As temperatures drop, they freeze about 60-70% of the water in their bodies, stopping their heart, breathing, and brain activity.

They produce natural antifreeze in the form of glucose, which prevents their cells from completely freezing. Ice forms outside their cells and in body cavities, avoiding tissue damage. When spring arrives, the ice melts, and their body functions gradually resume, allowing them to recover fully after months of being frozen. This unique adaptation enables wood frogs to survive extreme northern climates.

4. They Immediately Start Breeding In Spring

When wood frogs emerge from the frozen winter, they immediately begin mating. They waste no time finding a mate when the weather warms in spring.

In fact, wood frogs are some of the first frogs to begin the mating season. They start breeding in early March and continue through May. Tadpoles and froglets emerge in the summer.

5. They Make A “Quacking” Call During Mating Season

Wood frogs are usually quiet outside of the mating season. However, during mating season, you’ll certainly know exactly where they are! Males call loudly throughout the day hoping to attract females. The frogs are usually clustered together in small pools and ponds, and the chorus of all the males calling together is quite loud! The sound often sounds like the quacking of a duck. 

6. Males Can’t Tell If Another Wood Frog Is Male Or Female

A funny thing about male wood frogs is they can’t tell the difference between another male and a female. They get so excited with another frog they just latch on their back.

Males can only tell the difference once they latch onto a potential mate. Females tend to be larger and let males stay on. Other males will wrestle off the unwelcome advances.

7. Tadpoles Eat Other Wood Frog Eggs

Wood frog tadpoles mostly feed on algae, plant matter, and tiny insect larvae. However, they’ve been known to eat their own.

Tadpoles will eat other wood frog eggs. Even though they’re primarily herbivores, wood frog tadpoles can be cannibalistic if food is scarce.

8. Females Lay Over 1000 Eggs

Typically, a female wood frog lays about 800 to 900 eggs per clutch. Depending on conditions, they can lay as few as a couple hundred or as many as 1,500 eggs at a time.

The jelly-like egg mass can be about the size of a softball. Female wood frogs lay their eggs in the water next something the egg mass can attach to and camouflage with, like a submerged branch.

9. Multiple Females Lay Eggs Together

Egg mass in ponds can grow pretty large in size when multiple females occupy an area. Masses can reach 3,000 eggs or more. Tadpoles make good food for many other creatures inhabiting the pond, so by having such a large number of young, it ensures a percentage will survive to reach adulthood. 

10. They Have An Attack Reflex

Wood frogs are carnivores and also predators. They use their sticky tongue to grab insects and other small prey. These frogs have an instinctual attack reflex. This means if they detect any kind of movement that could potentially be prey, they lunge and whip out that sticky tongue.

11. They Have Nearly 360-Degree Field Of Vision

With the position of their eyes, wood frogs can see all around their body without ever moving their head. They have a field of vision that is 360 degrees.

This allows them to see predators sneaking up from behind. The frog can escape before the predator knows it’s been seen.

12. They Have Hyperoptic Vision Underwater

Wood frogs, like many amphibians, experience hyperopic (farsighted) vision underwater, allowing them to see more clearly and focus better below the surface. When they are above water, they experience myopic (nearsighted) vision, which means they rely more on detecting movement than on sharp focus. This adaptation helps them capture prey and detect predators effectively in both environments.

13. They Wear A Mask

You a helpful way to identify wood frogs is by their facial marking. They wear what looks like a “robber’s mask”, a dark band that goes from their eyes to the side of the head.

Wood frogs also have dorsolateral folds, that are two raised ridges that go from their eyes to their back.

14. They Secrete Toxins

While they’re not poisonous to humans, wood frogs secrete a toxin from their skin as a defense mechanism. This defense is meant to protect the frog from predators.

Their toxicity is low and primarily affects smaller animals that might try to eat them. They secrete a mild skin toxin that can irritate the mucous membranes of potential predators, deterring animals like raccoons, snakes, and birds. While not harmful to humans, their skin secretion might cause mild irritation if handled, so it’s best to wash your hands after contact with a wood frog.

15. They Live For About 3 Years

Wood frogs have relatively short lifespans and only live about 3 years in the wild, though they can live up to 5 years or so. The primary threat to wood frogs is habitat loss due to deforestation and pollution. Tadpoles die from polluted water sources, and human encroachment continues to be a problem.