My experience with frogs in southern Michigan has more to do with birds. My first year pond has nothing in it but GS. Lots of GS. (no predators) Last spring I put in some tadpoles from a near by puddle and combined with what otherwise found their way in, by mid summer the frogs were thick. Walking the pond perimeter was fun just to see the abundance of frogs jumping into the water from the banks. However, not too many weeks after noticing GB Herons (2), and at least one Egret, prowling the shore line, I began to notice the frog population had dramatically declined. This in spite of the fact that I had purchased a fake Heron in anticipation of the bird problem.

I had previously noticed Herons on the Lake I live on, consuming some really large frogs. My point here is that there are more things eating frogs (and small fish and minnows) than just LMB. Keep your eyes open for birds.