Yak 1 and yak 2?

My somewhat limited knowledge of aircraft suggests that these are Yaks. I googled it and ended up no better informed but the wing tips are typical of a Yak  although the side on shot I got shows a square top on the tail while all the Yak pics I found show a rather large rounded tail.
Anyway they churned up the atmosphere around here for about an hour this afternoon which was a bit of fun entertainment on a sunny day.