The yellow jackets are in abundance near the river this year. We have had four nests on our tiny lot including one in the wall. Our next door neighbors have two, one in a wall as well. The community garden, which often doesn't have any, has had three this year and there's another on the nearby bike path.

However, the mud-dauber wasps are missing this year. We usually have many of their hives in the garden and there aren't any this year. Also, there does seem to be a reduction in bats and hummingbirds. 

I honestly don't know what any of it means. It could be natural variations. It could be temperature/rainfall related, especially with the yell0w-jackets. There are also less-pleasant possibilities.