Oh my god yes... I have been hearing that same thing from some baby iguana owners. Being plucked right outta the yard by hawks and such. Be VERY VERY careful!!!
:I had some sunning cages similar to those (same sort of concept) and a large predatory bird took off with one of my juvie nigerian uros! You might want to put some chicken wire over the top! :) They look happy and great, though!