This video from the USA says about itself:
A Mourning Dove is having quite the time deciding what little piece of root it wants. It” s the end of August  so I don’t know what it wants to do with it – nest building is a little late. The doves have been attracted to this digging site around a deck I’m fixing for some reason; I thought maybe the clay or loose dirt. Doves tend to have an indecisive look about them anyway. It likes the real long root, but it’s still connected, so the quest continues until it slowly walks away with just the perfect little piece of root.