I started going down to this local pool probably 15 years ago or more. It had been a simple farm pond on the old Condon homestead. It had a large culvert above it that went under the road and a tiny stream that went down the hill in spring to the bog. The first time I went there were male frogs calling in the females. The second time the next day a male and female on a floating log coupled. I read they can hold on for 24 hours. Over the next week clusters of eggs started to appear. And then I saw salamander egg sacs hanging in the water. I spent spring near this pond. The frogs hatched and the pond was full of tadpoles, tails grew and legs. And then they were gone off into the woods.
This pattern went on for several years. And then the bullfrogs arrived. No the thing about bullfrogs besides being big is that they overwinter so the tadpoles have a head start and they wake up hungry. That year hardly a wood frog egg got to hatch. The next year it was the same. The bullfrogs had taken over my little spring pond.
I stopped going by as regularly and then someone bought the land and started moving dirt. The pond was full of silt that year and the egg clusters were coated and smothered.
The following year he bulldozed around the pond and when he was finished the pond was not the same. One side was a mound of dirt and the pond has not filled again. 2016 was the last year I saw eggs. That was th year of the silt.