Identifying bird from laid egg (grass, trees, snakes, vegetable)

[Tek_Freek]

When I mow I toss untreated grass clippings in my vegetable garden for mulch. This morning I noticed an unbroken white egg about the size of a Robin's egg laying on the mulch. There was the barely discernible mention of a nest, basically just some of the grass pushed away from the egg in a circular pattern. No depth to it.

I don't think it fell from a nest because there are no trees or limbs above the area, being a vegetable garden I want sun.

Does anyone have an idea what this might be.

Central Iowa. It's not speckled so I don't think it's a Killdeer.

[jimboburnsy]

Do you have any species of quail in your area? I woud be tempted to say purple martin, but actually crafting a nest on the ground is unheard of. I think that some species of mourning dove will occasionally nest on the ground,

[poconoproud]

maybe box turtle eggs? but I thought they would bury them, so raccoons and other animals don't eat them.

[pitt_transplant]

Photo?

[poconoproud]

you can rule out grouse, they have colored eggs.

[pitt_transplant]

Eggs can differ in color sometimes.
I have found almost white robin eggs. Even a greenish one.

[poconoproud]

Tek - the mystery will kill me! Hopefully you will let us know when whatever it is hatches?!

[pitt_transplant]

what about snakes?
Are there snakes there that lay eggs?

[AliceT]

Are you sure it's a bird egg? I'm thinking reptile. Quail is another possibility. And there are several birds who lay their eggs on the ground in a shallow burrow, but I tend to doubt they would be that close to a yard that gets mowed. Birds are really careful about that sort of thing.

[mrs1885]

Ok, not the nightjar:

Nightjars lay one or two patterned eggs directly onto bare ground.