Must be Spring: Mockingbirds arrive

As I was walking to the car, I realized it must be spring here on the South Plains: there was a mockingbird singing his fool head off (every other bird song he could think of).
We've had one who comes back to live in the almost-broken-down Black Walnut in our front yard each summer for the last three years. He usually starts up about 4:30am.

As I said: Must be spring.