Can anyone tell me how to get rid of barn swallows?

The place we moved to recently had several newly planted trees ( less than 2 years) We have noticed bark damage on several of the trees, it comes off in large pieces, what is causing this and what can we do to save the trees. They are southern red oak and red maple.

Thanks

Hello! I realize you posted this long ago. Have you since tried posting it in the "Trees" forum or the "General Garden and Landscaping" forums? "Backyard Birds and Birding" might be helpful as well.
Cheers!