Protecting Eastern phoebe's babies?
I'm new to this forum and apologize if this kind of question has been asked before...
For the second year, we have an Eastern Phoebe building a nest on the ledge/trim above our front door. It is a great site for her in many respects because the door is set back in a little alcove and the whole thing set back because the house is a Dutch Colonial with a deep overhang in front. HOWEVER... there is a wide bluestone stoop at the door. Last year, I believe virtually all her little ones fell out and died when they struck the bluestone step. I don't know if they crawled over the edge of the nest, or if they tried to fly, but I picked up four little carcasses over several days. We meant to put up a row of pebbles (which were there when we bought the house, I guess for this purpose?) on the ledge this year to discourage her, but didn't get to it before she started building.
So my question is this: is there something I can put on the bluestone beneath the nest to "catch" or otherwise soften the fall for fledgling Phoebes? I would really hate to see her lose another brood -- except for the bluestone (and the fact that we don't want to turn the outside lights on at night!) we enjoy having her around. She seems a very attentive mother (just not so good at picking housing sites). I don't want to intervene with nature too much, but imagine in the wild, there would be something soft underneath her nest, not an expanse of stone. What can (or should) I do to help her out, if anything?
Many thanks for your help!