How do I stop my dog from going after birds?

I have a 1 yr old male shih tzu named Conner. He’s a very sweet and loving dog but he keeps going after birds.

We have a big fenced in yard and we like to let Conner run around in the yard. There are a couple of birds nests in the trees and I’ve seen and heard baby robins. Sometimes these robins are in the grass and Conner will see them and he will go after them. He’s not vicious about it he just thinks that the birds want to play. There have three incidents this week where he has caught baby robins. We try to watch Conner to make sure he isn’t going after birds.

I don’t want him to hurt any birds. What can I do to stop Conner from going after baby robins? Any suggestions for how I can break Conner of this habit?

work on recall or keep him on a leash.

Kevin Macdonald at the Mass Observation Archive