You probably see a lot of frogs and hear their various calls during the spring and summer breeding season. But where do frogs go in the winter? Since they are cold-blooded and the surrounding weather influences their body temperature, it’s easy to wonder if they simply die and repopulate after the winter. Let’s find out answers to this question and more about what frogs do in the winter.
Where do frogs go in the winter?
Depending on the species and their habitats, different frogs do different things to adapt to winter conditions. Some terrestrial frogs will burrow into the ground while others seek shelter underneath leaf litters, holes in logs, or crevices in tree bark once the weather gets colder. Aquatic frogs will stay in the water by partially burying themselves into the mud at the bottom of streams or ponds.
During this period, frogs will slow down their metabolism, lower their body temperatures, and drop their respiratory rates. Although similar to hibernation, this process is called brumation. Some frogs can even move around still. For example, aquatic frogs may slowly swim from time to time during brumation.
What is the difference between brumate and hibernate?
Sometimes these two terms are used interchangeably because they are very similar to each other. They are what animals do in the winter when food is scarce and similar to a “deep sleep.” Metabolism and other body functions are slowed down to conserve energy to survive.
Animals that hibernate are warm-blooded, while animals that brumate are cold-blooded. Hibernation tends to occur longer and in a deeper state than brumation. Additionally, animals that hibernate will eat more food before to store up energy as fat. In contrast, before brumation, animals tend to stop eating since they won’t be able to digest the food as well.
Can frogs freeze without dying?
Yes, they can. Since frogs are cold-blooded, their bodies take on the surrounding temperature of their environment. Add the fact that their brumation sheltering habits seem less warm and cozy, there’s no surprise they can sometimes freeze when temperatures drop dramatically.
Frozen or partially frozen frogs will appear dead since they stop breathing and their heart stops beating. However, their liver increases their blood-sugar levels and this acts as a natural “anti-freeze” to prevent ice crystals from forming in their body. Ice crystals formations can damage their tissues, which would lead to death.
Frogs will begin to thaw once the weather warms up, and their lungs and hearts start working again. If they emerge too soon, however, it can result in death.
How cold is too cold for frogs?
Although most frogs can freeze and come back to life, there is such a thing as temperatures being too cold. For example, aquatic frogs may die if temperatures drop below 29 degrees Fahrenheit since the water’s oxygen levels also drop at this temperature.
Generally, frogs can survive temperatures at or above 30 degrees Fahrenheit. However, some species can survive temperatures as low as 23 degrees Fahrenheit. Tree frogs are typically the most resistant to the cold since they can freeze around 40 to 60 percent of their body’s water content and still re-emerge.
Do frogs migrate?
You won’t find frogs migrating long distances to seek warming locations during the winter like some species, such as birds or whales. However, frogs will migrate from shallow breeding ponds during the summer to the deeper lakes where they spend the winter. Some frogs that live in damp areas of woods will also migrate to wetlands or ponds during mating season to lay their eggs.
Typically, larger frogs are known to migrate longer distances than smaller ones to seek out winter habitats. For example, red-legged frogs (Rana draytonii) will migrate from breeding ponds between 0.5 and 3 miles away. This species is the largest native frog in the western U.S., growing between 1.75 and 5.25 inches long.
How do you tell if a frog is dead?
Since brumating frogs can seem like they are dead, it’s sometimes hard to tell the difference. Besides not breathing and their eyes closed, signs that a frog is dead include:
- Dull coloration
- Lying belly up
- Floating in the water without movement
However, some frog species, such as litter leaf frogs (Ischnocnema henselii), also play dead to trick predators. This species will turn belly-up, shut their eyes, and dramatically throw back their arms and legs. One way to see if a frog in this position is dead or not is to watch how long they stay in it for. Typically, they can stay in this position for around 2 minutes. If hours have passed, they are probably dead.
Frogs typically don’t go far during cold winter months. While some will migrate from shallow ponds to deeper ponds, they only do so to find a suitable habitat to brumate in. Different species spend the winter in different locations, ranging from burrowed underground and hiding in log crevices to partially burrowed in the mud at the bottom of ponds. Frogs are sturdier against the cold than you may think! Since some species can freeze and come back to life.