Pollywogs are fascinating

Walking close to the water along the banks of the Rideau River in springtime, I see thousands of pollywogs (also known as tadpoles). I decided to dedicate one of my walks to getting some closeups of them in the early morning, and I got some fascinating shots of these tiny creatures.

Being a tadpole is part of the life cycle of all frogs and toads. Looking at this big crowd, it’s easy to believe that in a few weeks the city will be overrun with teaming frogs! But in actuality, almost every other river creature eats these little tadpoles! Ducks can be seen gobbling them up quite rapidly. And other aquatic birds find them delicious as well.

Apparently, this is why frogs produce thousands and thousands of tadpoles in a season. It’s likely that only 2 will survive into adulthood to replace the parent frogs.

Just before breeding, the females lay their fertilized eggs into the still water. The male fertilizes the eggs as the female releases them and they clump together to form spawn. Then, in most cases, the parents leave their eggs, and in a few weeks, the cells in the egg divide to give rise to the tadpoles. A couple of weeks later, the tadpoles are ready to come out into the open. Till now, the nutrients they needed were in the eggs. But now they have to go out in search of the food. So off they swim in search of algae and tender plants to feed on.
As the tadpoles continue to eat, they grow in size and develop limbs, with the back legs growing first and the front legs second. At between 9 and 12 weeks, the tail begins to diminish, and the tadpole now has more significant limbs. It is now a froglet, a young frog, and can eat larger plants, and even insects. It starts to use its newly developed lungs instead of gills to breathe, and tadpoles at this stage will often swim to the surface and gulp air.

This means that soon the frog can hop onto land and feel comfortable in or out of water.
Curiously, the name tadpole comes from Middle English - tadde = ’toad', and pol = ‘head'. So, “toad head” lol.

The name pollywog is made up of the same pol, 'head', and wiglen, 'to wiggle'. So “wiggle head”.