Canadian Tiger Swallowtail butterfly

My neighbor Doug called and said one of the bird houses I had put up on his land had fallen down.  He was willing to reinstall it but I wanted to see what  caused the failure.  Drove over and, as he said, the bird house was on the ground and there were two house sparrow eggs in it.  I checked the other bird house there.  It has tree swallows and their babies were just born and featherless yet.  Thankfully  they were OK.  So - probably not an animal looking for a meal.  Animals would have heard or smelled the baby birds and gone for them before the house w/ eggs.  We had quite the thunderstorm last night but that shouldn't have been enough to dislodge the house.   The pole and hanger were in good shape.  Have never had this happen before.  I cleaned out the downed box and reinstalled it.    Was still thinking about it when I saw this butterfly flitting between orange hawkweed flowers growing in my lawn.  Took a picture and made a mental note that it was time to mow.