Thanks for all the great responses!
I forgot some information, like location and weather!
I am in the lower panhandle of Idaho. We didn't have a hard winter, and have had a really hot summer.
It's well known that a huge den of snakes is in our area; everybody along the creek has always had tons of them from early spring til fall...but not
this year!
I am the only one I know of who 're-locates' them, so I don't believe I've eliminated them.
Garter snakes DO harm fish. They eat all the fry ( as many as 6 in the pond on any given day when the fry hatch) and I have personally watched garters
wrap around the smaller fish like a boa constrictor and drag them out of the pond. That was the day I declared 'war' on them...
Their food source is just as plentiful as it's always been. I do have more honey bees than usual, and less yellow jackets.
I haven't seen a Bufo toad in two summers, which is odd. I also have a definite lack of mice in the garage, and I have been at war with them since
the beginning! Moles have also been a huge problem...but I only haven't had any this year.
I am two blocks from the old railroad tracks, and for the first time since living here the tracks are over-ridden with rattle snakes. They've always
liked the tracks, but they're exceptionally thick this year.
The food source is still here in town for reptiles, rodents and birds....but they are scarce. Garter snakes are very prolific breeders, so I seriously
doubt my efforts could have had that much of an impact on the whole town, but I can't think of an environmental cause.
I find it curious that some areas are seeing more wildlife than ever before, while some are seeing less. If it was a cyclical thing, I would expect to
see at least a couple of snakes throughout the summer!