Least Flycatcher?

[kfhgw]

I took this picture yesterday in northern Illinois, in a woody area by water, in the morning.  Is it a Least Flycatcher?

Thanks in Advance

Karen

[Charlie Spencer]

You've got a Ruby-crowned Kinglet.  That's a great picture of a species that's notoriously difficult to photograph!

https://www.allaboutbirds.org/guide/Ruby-crowned_Kinglet

[IKLland]

Behavior is all you need to differ from a flycatcher! Flycatchers stay somewhat still on a perch, fly off to catch a fly, and return. Kinglets flit around in trees or bushes constantly. 
 

Also, the structure of the bird differs fro, flycatchers, but that’s harder to learn. Kinglets tend to be rounder, and chunkier, while flycatchers are much slimmer in appearance. 

[Peromyscus]

That is a really nice Ruby-crowned Kinglet photograph!