I'm on a farm in central Minnesota and seeing a lot of small birds on my green lawn. They look like audubon warblers. I've never seen them before and am not sure about what they are. They seem more interested in my lawn than the trees. We have had a lot of rain and that seems to bring a lot of earth worms closer to the surface. It is May 6th. We have so far had a very cold spring. The yellow spots on the head side and rump make them noticeable and they are blue grey on there backs. some are much browner. Would that be the females?