WRT fewer frogs around ponds I believe another large contributor to fewer frogs is predation. There are more preditors of frogs than in the past.
I know when I was growing up the fur market was booming & the varmits that eat frogs were kept in check. Nowdays with wearing fur being PI trappers numbers are few due to low fur prices.
I don't grow sweet corn because the coons eat it all leaving nothing for the table.
