My zebra finches that i keep in an open flight avairy had just had babies. One of the babies was this beautiful pure white male with two black teardops under his eyes. I must have him i thought. So i cleaned out the old budgie cage and spent all weekend trying to trap this baby zebra(he was old enough to fly...and outsmart me). Eventually i got him, i was so happy. I took him up to a nice ledge outside my bedroom window (3 stories up) and sat the cage there. I left the next day for school, and on my return found him IN TWO PEICES!!! 3 stories down on the pavement below my window. i almost fainted. Turned out the Miner Birds had found him and pryed him out of the cage before brutally murdering him and throwing him off my balcony.
The messgae behind this is be careful about what cages you leave your precious pets in outside becuase the worst could happen. Its like what mickp said
I guess the wild birds are just doing what comes naturally. it's up to us to make certain that our cages/aviaries are secure so that this is unlikely to happen