A lot of replies to my comments mention environmental pollution. I definitely agree there is less now. I was recently shocked to see that the once nasty brown river that runs through my home town is now Nile blue. The numbers on pollution levels agree with this anecdote too.
However, no one I asked had seen a horned toad or armadillo in years. And these are definitely the kind of folks that used to. Cicadas used to deafening on summer evenings, but now they were barely audible. Sample size = 1, but the numbers seem to bear out these anecdotes too.
It's totally possible for both of these to be true. Pollution can go down at the same time that animal populations are suppressed for some other reason.
However, no one I asked had seen a horned toad or armadillo in years. And these are definitely the kind of folks that used to. Cicadas used to deafening on summer evenings, but now they were barely audible. Sample size = 1, but the numbers seem to bear out these anecdotes too.
It's totally possible for both of these to be true. Pollution can go down at the same time that animal populations are suppressed for some other reason.