When summer arrives, many creatures become more visible, but toads often seem to disappear. Toads engage in burrowing, a specific behavior that allows them to survive the challenges of the summer season. Their ability to dig into the earth provides a solution to several environmental pressures they face.
Surviving Summer Heat
Toads are amphibians, meaning they are ectothermic and rely on external sources to regulate their body temperature. This makes them vulnerable to extreme heat and dry conditions during summer. Their permeable skin, while allowing for gas exchange and water absorption, also means they can lose moisture rapidly. Burrowing provides a way for toads to escape the sun’s direct heat and the risk of dehydration.
Underground, the soil offers a stable, cooler, and more humid microclimate. By retreating into the earth, toads can maintain a more consistent body temperature, often around 30°C, even when surface temperatures are much higher. This helps them conserve body moisture, as the cool, damp underground space protects them from drying out. During prolonged hot and dry periods, toads enter a state of dormancy known as aestivation. This involves slowing their metabolism, reducing their need for food and water, enabling them to endure until more favorable conditions return.
Finding Shelter
Beyond regulating temperature and moisture, burrowing offers toads additional protection. Burrows provide a secure hiding place from predators like birds, snakes, and mammals. By disappearing underground, toads become less accessible to these hunters, particularly when vulnerable.
Burrowing also shields toads from other harsh weather conditions. Strong winds can accelerate moisture loss, and heavy rains can dislodge or harm toads exposed on the surface. An underground retreat offers stability and cover. Toads may also utilize existing burrows created by other animals or natural crevices for refuge.
How Toads Burrow
Toads are skilled diggers. They employ a unique backward-digging technique to create their burrows. Instead of using their front limbs like many other burrowing animals, toads primarily use their strong hind legs. These legs are equipped with hardened, spade-like projections on their feet, which are specifically adapted for excavating soil.
As a toad digs, it pushes its hind legs backward, kicking dirt out behind it. This motion allows the toad to gradually sink tail-first into the earth, creating a depression that becomes its burrow. The depth of these burrows varies depending on the toad’s immediate needs, from shallow refuges for temporary daytime concealment to deeper chambers for extended periods of aestivation. This instinctive behavior allows them to customize their underground retreat, whether in soft soil, sand, or leaf litter.