Wood Frog
Wood Frog Facts
Size | 2-3 inches (5-8 cm) |
Speed | Unknown |
Weight | Up to 0.2 ounces (8 grams) |
Lifespan | 2-3 years |
Food | Little vertebrates |
Predators | Snakes, herons, owls, raccoons |
Habitat | North America, Alaska, Canada |
Class | Amphibians |
Order | Anura |
Family | Ranidae |
Scientific name | Rana sylvatica |
Characteristics | Frog that lives the farthest north; survives freezing |
Main Characteristics
The wood frog is a small amphibian with an unique ability: it can survive at a body temperature of 21 degrees Fahrenheit (-6 degrees Celsius). This means it can freeze and thaw without dying. Among all frogs, it lives the furthest north, being the only species that can survive north of the Arctic Circle. Its secret to enduring the frigid cold lies in its use of glucose and urea for protection. We'll explain how this works in more detail below!
Distribution and Habitat
The wood frog can be found in Alaska and Canada. Its habitat is ponds, wetlands, and forested areas.
Way of Life
Wood frogs are diurnal animals. They mainly live a solitary life. Each year, they return to the same pond to breed.
Anatomy and Appearance
Size and Weight
Wood frogs typically measure 2-3 inches (5-8 cm) in length and weigh around 0.2 ounces (8 grams).
Color
Their coloration can range from yellow-brown, gray, orange, pink-brown, to gray-green, and many feature a distinctive white stripe along their back.
Robber's Mask
Among the 5,800 species of frogs, there are 260 that are classified as "true frogs." Distinguishing them at a glance can be tricky, especially when they hop by quickly. However, identifying a wood frog is quite straightforward. It has a prominent thick black stripe running across its face, resembling the black mask of a bank robber.
Diet
Wood frogs are carnivores. They feed on spiders, snails, worms, and insects. Tadpoles consume plants, algae, larvae, and the eggs of other amphibians.
Behavior
Defense
Wood frogs face numerous predators, but they aren't completely defenseless. When an enemy approaches, they produce sharp sounds and release a toxic fluid from their glands.
Senses and Abilities
Torpor
No Breathing, No Heartbeat
Are there animals that can freeze and come back to life? Yes, the wood frog! When temperatures drop below freezing for an extended period, not only does the ground freeze, but the wood frog does too. It stops breathing, its heart ceases to beat, and it remains in this state until spring. How does it manage that?
Glucose and Urea Do the Trick
To ensure that the wood frog doesn’t literally bite the dust during its hibernation, it fills its body with a significant amount of glucose (= sugar) and urea beforehand. These two substances help prevent the formation of dangerous ice crystals in its body cells, which could cause serious damage.
As Low As 21 Degrees Fahrenheit
However, this ability has its limits. If more than 65% of its body fluids freeze, the forest frog won't make it. Additionally, its body temperature must not drop below 21 degrees Fahrenheit (-6 degrees Celsius). Fortunately, it usually finds a sheltered spot that helps it survive.
Sense of Smell
Wood frogs begin to recognize the scent of their predators while they are still developing into tadpoles inside their eggs.
Color Change
Wood frogs have the ability to change their color, shifting from light to dark and back again. They don't do this for camouflage, but to regulate their body temperature. In cooler conditions, they turn dark to absorb as much warmth from the sun as possible. When it's warm, they lighten up to reflect sunlight.
Life Expectancy
The wood frog has a limited time to reproduce, typically living only 2-3 years.
Enemies and Threats
Natural Enemies
Wood frogs face predation from garter snakes, water snakes, larger frogs, herons, owls, skunks, minks, and raccoons. Tadpoles are a favorite treat for diving beetles, tiger salamanders, and water beetles.
Human Impact
The wood frog isn't considered an endangered species. However, it is disappearing from many areas due to the draining of ponds and deforestation.
Importance for the Ecosystem
Wood frogs play a crucial role in maintaining the balance of insect and spider populations with their healthy appetite. At the same time, they serve as an important food source for predators.
Reproduction
In the spring, wood frogs come together to mate. During the mating process, a male clings to the back of a female. After fertilization, the eggs are laid just beneath the water's surface, with a single clutch containing around 2,000-3,000 eggs. The tadpoles hatch after about 9-30 days and will grow into frogs within a year.
The Wood Frog Is Related To:
- Goliath Frog
- African Bullfrog
- American Bullfrog
Animals in the Same Biome:
Sources:
- "Wood Frog" (https://ontarionature.org)
- "Urea hydrolysis by gut bacteria in a hibernating frog: evidence for urea-nitrogen recycling in Amphibia" (https://royalsocietypublishing.org)
- "The ghost of predation future: threat-sensitive and temporal assessment of risk by embryonic woodfrogs" (https://link.springer.com)
Related Articles:
- Animals and Their Tricks for the Cold
- All About Frogs and Toads
- Frog or Toad - What’s the Difference?
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