I would say post this over on the BIRD WATCHING forum...THEY'RE AWESOME!...they'll help you!

Here is a link that might be useful: bird forum

I posted messages in both forums, just to cover my bases. Thanks, though. :)

Well, this is an emergency. Possibly you could fashion some sort of cup out of soft material and place it under the existing nest. Something like rolled up pantyhose or a small plastic container with plenty of holes in the bottom in case it rains. If you wedge something in between some branches for support and replace the nest close to where the existing nest is now, they will probably be just fine. VAL

Do you know what kind of birds they are? I have replaced entire nests for some species and had no problem at all.

The birds are wrens. The babies don't have full feathers yet, just "quills" and fuzzy bald heads.

Would the mother bird detect/notice the nest was damaged and maybe fix it?

Holcombee: What kind of wren? I'm guessing maybe Carolina? I doubt she would fix it, but I have no real reason to say that. It just seems to me from observation that birds are more fixated on feeding the babies than anything. I don't know how she'd be able to fix the next from the top with the babies in it. I also wonder if she would notice that the bottom of the nest was in need of repair and/or have the sense to do anything about it. Having said all of that it is merely speculation. If the babies do fall out, the parents will still attempt to care for them if they are healthy, but they are likely to become the prey of another bird or cat or night predator.

I guess if you do decide to shore up the nest somehow, you should make a solid plan and have a helper ready to hand things to you or run for something you may need. The parents are likely to be somewhat upset, and you want to be able to work as quickly as possible. I have used a deep bucket in which to carefully place the babies (I pick up the whole nest and babies by scooping it up with two hands). I cover the bucket with a towel so that the babies do not become prey or get overheated by the sun. Then I have fashioned nests out of similar materials making sure to try to work the materials into a cup by putting my thumbs into the middle. I just try to get it as close to the old nest in shape and materials as possible. Once I have the new nest in place, I then replace the babies carefully. In the cases that I have done this, they have always been in a nest box, so it is easier to be sure the babies will stay put afterward. The real danger here is if the babies are of an age that they could jump ship and you cause them to fledge prematurely out of fear. Can you tell about how close they are to fledging? Are the eyes open, do they permanent feathers yet? If they are close to fledging, I'd leave nature to her work.

This is not an ideal solution, and I'd only use it if absolutely necessary. I think if you are able to add anything under the nest, that would be the best thing. This is one of the reasons that there is such mortality rates in songbirds under one year. Good luck and keep us posted.

The babies tend to scoot to the edge of the nest when I get too close and look ready to fling themselves over the edge - which I definitely do not want!

Thank you all for your advice! Please continue, however, I have decided to continue to monitor the nest and if it appears to worsen I will step in and reinforce the nest with an extra set of hands, too!

Maybe a square of hardward cloth could be somehow fastened by the corners to the branch the nest is on? It would have large enough holes to allow rain water to drain but keep what is left of the nest secure till the babies fledge. I don't think I would take the time to try to do much rebuilding - you just need something to hold it in place for a short time. Good luck.