Vernal Pools – An Amphibian Bonanza

Look down the slope from this point and you will see a depression in the landscape where water collects. This is an example of an ephemeral pond, also called a vernal pool. These wetlands are incredible places in the spring and early summer, and prime breeding grounds for some of Haliburton’s amphibians. In the spring, as the snow begins to melt, water collects in depressions such as these. Triggered by the spring rains, the first amphibians to appear are the salamanders, often in massive numbers. They cross the forest floor, over snow, ice, logs, and debris, heading blindly in the direction they were born, and returning to the exact same pool where their lives began. Upon arriving at the pond, the salamanders court, pair, mate, and eventually lay eggs in jelly-like, globular clusters. This explosive breeding event is over as quickly as it began. The next to come are the frogs, especially Spring Peepers and Wood Frogs. The former species, barely larger than your thumb nail, emits an incredibly loud, high-pitched call.

The Wood Frog, on the other hand, is more reminiscent of a cackling duck. The combined chorus, however, can be absolutely deafening, as they call with the intensity of a smoke detector! The frogs call incessantly in the hopes of attracting a mate. Like the salamanders before them, the frogs pair, mate, lay their eggs and leave the pond to spend their summer in the forest. The eggs hatch quickly and the race to grow begins in earnest, as the young need to obtain enough nourishment to metamorphose before the pool dries up. So why ephemeral ponds? Why not marshes, or beaver ponds? The answer lies in predator avoidance. These ponds are fishless, providing a relatively safe haven to grow quickly without being eaten. With climate change, these habitats are at higher risk of drying early, directly affecting the survival of the amphibians utilizing them.