Migration is upon us. Not everyone enjoys birding in the fall, some species can look different in the fall since they aren't in breeding plumage. Young birds haven't grown into their adult plumage yet. Birds usually don't sing their territory song on the way south, but rather chip notes that can sound the same among several species--it can be more of a challenge.
I found one bedraggled looking sparrow the other day. Song sparrows usually have a very long tail which makes them easy to pick out, even if you only see the profile. When I saw this bird hopping in some bushes, I was interested. I made the pishing sound and it popped right up just like a song sparrow should and it appeared to be lacking a tail. Who knows what happened--an overzealous molt? An failed grab from a sharp-shinned hawk? But it's all part of the fun of weird birds on the fall migration.