darius, I hope someone will be able to answer your question. I'm relatively new at birding and have seen very few eggs in person, thus unable to assist with your quest for an answer. From what I've observed, some common garden birds will use nest boxes, those that nest within shurberies are Mockingbirds, Thrushes, Brown Thrashers ect. I just wanted to share bit of my experience, and hope to bump this thread up for an answer. Good lucks.
Those poor Wrens, they have a tendency to build nest in every odd place. Early spring my son found a nest that was built in his hanging flower basket... The Wrens wasn't discouraged by human activity, but when it tried to incubate, and the basket was taking down to be watered. The Momma bird got frightened and abandoned the clutch of half dozen or so eggs. Such bad outcome!!!
DariusI'm not so sure its a Wren. The Carolina Wrens here are picky. They like sheltered areas like in hanging basket under a porch, a shelf in the garage, stack of plant pots laying on their side. The always build a domed nest (like a cave) even inside a bird house. They will build it up to where the opening of the nest is aligned with the opening of the birdhouse. I have one in a Bluebird box now. If I don't forget I will open it when I can catch the mom off the nest and take pic to show you.
Found this info on birds nest from here http://northernwoodlands.org/articles/article/which-bird-made-that-nest/
"Chestnut-sided warbler Dendroica pensylvanica
Chestnut-sided warblers nest in open, edge habitat and also close to the ground, in small shrubs and bushes. This nest, with its very light and flimsy appearance, is made almost entirely of very fine grasses"
Haven't googled to see what their eggs looks like yet
Carolina Wrens in Somerset, KY don't build on the ground that we've had here every year that I've noticed. This year they are on the edge of the base of the porch after 2 - 3 feet up but to put it directly on the ground I haven't seen yet.
I found an identical nest last year which I accidently exposed and ruined weeding the garden. That is the egg was OK but it was too exposed for the bird's liking. The parents never came back.
What I saw flying away from it and it was only a glimpse, looked like a barn swallow.
I'd like to know if you identify this bird's nest.
Here is a link to a similar looking Barn Swallow nest, though placed differently.