binibusybee wrote: I have a fairly large pond which has been going for about 4 years now. We live near Ottawa , Ontario. The local Leopard frogs found the new watering hole in no time and entertained us with their songs and dance, just days after we had filled it up! Last summer the ponds' sides were practically covered with frogs and I had to scoop out lumps of eggs which had gone rotten (too hot I think).
To my surprise I found large tadpoles emerging from under the ice this spring! They still haven't grown legs but we had a cold, rainy spring. But the adult frog population seems much diminished from last year. We do have raccoons and other wildlife in the area, or is it possible that the frogs moved away to make room for the new generation??
One more question: does the quality of the pond water get affected by a large population of frogs? I imagine they poop in the water since I haven't come across anything resembling frog poop on the sides. Our pond is unlined, natural clay bottom with lots of plants and we top it up with well water when it gets too low. We have some 'Sunfish' from the local river for mosquito control. If they eat small tadpoles then they obviously just thinned out their numbers as there always seem to be plenty.
You mentioned bull frogs in your article. I have had bad encounters with those monsters! They would fall into our swimming pool in Zimbabwe and we would have to fish them out - a chore i did not enjoy as the bullfrogs angrily sink their fangs into the scoop net! I always tried to deposit them into the wild as i had visions of being attacked by bullfrogs lurking in the shade of the shrubbery. Our boxer dogs occasionally ended up with a bullfrog attached to their jowls! But they are very vulnerable when emerging from their summer cocoon/hideout - and thats' when they are 'harvested' by animals and the native population.