How do amphibians survive the winter in temperate climates?

In temperate climates, amphibians survive the winter by entering a state of dormancy known as brumation. As ectotherms, their body temperature and metabolic rate are heavily influenced by the environment; as temperatures drop, their metabolism slows significantly.1234

To endure these conditions, amphibians seek out protective, stable niches to avoid freezing or extreme exposure:

• Aquatic species: Many burrow into the mud at the bottom of ponds or lakes. Because their metabolic rate is so low during this period, they can meet their reduced oxygen needs entirely through their skin, rather than using lungs.23
• Terrestrial species: Toads and some salamanders may burrow into the ground or aggregate in moist terrestrial environments, such as rotting logs or springs, to stay insulated.23

Beyond behavioral choices, some species employ biochemical adaptations. They may produce cryoprotectants—such as glucose or glycerol—which act as natural antifreeze to protect their cells and tissues from ice crystal damage. For instance, the wood frog can survive even when much of its body water freezes by using these internal chemical defenses.4