I am not sure if I should congratulate you or if sympathies are in order! A wild bird that nests nests so close is a beautiful experience, but you worry like crazy about them! A pair of Black Phoebes raise 2 nests of babies under my carport every year. I can't hardly relax until they leave the nest and are flying good on their own! I'm not familiar with wrens nesting habits, but that nest seems so exposed. Could you hang a couple of thick hanging plants a foot or two in front of them to hide them a little more? Crows, jays, and Magpies will eat eggs or baby birds if the see thout in the open. DON'T HATE THEM FOR IT THOUGH! Their babies need to be fed every few minutes from sunrise to sunset. The babies need protein which is insect. It takes lots of insects to keep 5 babies healthy and full. Their babies need as much meat or protein as hawks babies do. Corvids being as intellegent as they are figured out how to get enough meat like hawks do by killing birds. They just manage to do it without the beak and talons hawks have to kill with. If you buy a good high protein dry dog food and soak it in water, and put it far away from the wren's nest, that will help the other birds feed their nestlings and leave your wren's a little safer. Goodluck and enjoy!