My back yard is full of small, shallow holes and I'm trying to figure out why. They are 1-2 inches across and about as deep, definitely not burrows. I as far as I can tell, nothing is buried in them, and they don't seem filled in. These pictures are from last year, but there are dozens more in my yard right now. They seem to be concentrated around a certain spot in my back yard, but I've seen them all over. Based on the local wildlife, I suspect squirrels or rabbits (I live in Minneapolis, MN). I'd like to be sure what species is making them before I think about trapping and relocating it. Thanks in advance!
I tend to get shallow holes like this in my lawn in the early spring, too. Sometimes it's squirrels looking for nuts (or the tulip bulbs they've moved ... grr), but I found that many of them were appearing over night. It turned out to be skunks digging up grubs.
The difference I found was that the squirrels would tend to just have the shallow hole, whereas the skunk would leave a hunk of soil uprooted.
We might guess chipmunks. If you keep a close eye on the area where the holes are you may well see a head pop up occasionally and then disappear back into the ground. Holes may not be deep but connect underground a few inches down. Clusters of holes indicate you are close to a den where they have multiple holes for alternate escape routes. Chipmunk population numbers vary widely from season to season and even within the season; population numbers frequently crash to almost nothing and then they come back to clean out old foraging tunnels.
For a gardener, chipmunks are not as destructive of crops as voles (which spend their time much closer to the surface) but nevertheless can be a nuisance where the dens are particularly large. Underground cavities can cause subsidence.