Killdeer nest

Re the prior post, this is what I saw.

In the center of the road, nestled among four clusters of weeds, is a bird's nest.  The nest itself is comprised of local gravel and some gray dried plant stems.  It would have been VERY easy to totally not see it, since the eggs are so beautifully camouflaged against the gravel.  Here's a closeup of the nest:  (click either pic to enlarge)

It wasn't hard to guess the owner of the nest, because there are just a few ground-nesting birds in south-central Wisconsin.  The eggs and nest look like those of a plover or sandpiper; the local equivalent here is the killdeer.

A quick read on killdeer reveals that the eggs are large for the size of the bird because the young are "precocial" (able to fend for themselves soon after hatching) - apparently a trait common in ground-nesters.  The counterparts are "altricial" birds.

This trail that I enjoy walking is seldom used, but as evidenced by the mowed verge and the exposed gravel, there is occasionally foot and vehicular traffic.  The latter probably wouldn't endanger the eggs, but the former would, so after getting back home I drafted a warning sign and returned the next day to post it in the path:

On my return, the mama killdeer was nearby, and when she saw me, she immediately went into the classic "look at me, I have a broken wing" routine.  I tried to get closer to her for a photo, at which point she then trotted away from the nest, fell on her side again, and raised/flapped the wing again.  She led me about 40 yards down the path before taking flight and circling back toward the nest.

Update May 23:  The nest is still intact, and with ambient temps near 90 here, I have hopes that a succesful hatch may be coming soon.

Update June 1:  As I approached the nest again, I could tell through my binoculars that the eggs had clearly hatched, but it wasn't immediately obvious whether the chicks were alive or dead.   I understand the survival advantage of "playing dead," but I have no knowledge database re these birds.  I approached as close as I dared (about 8 feet) because I didn't want to flush the hatchlings if they were alive.  This was the view through my telephoto lens:

The camouflage is really quite good.  In addition to having a coloration similar to the surrounding rocks, the hatchlings' edges are so unclear that had I not known there were four eggs, it would have been hard to identify four chicks.  In this photo there are two on the left side with heads facing left, and two on the right, one with head toward the top, one with head toward the bottom. (Click picture for widescreen version).

I watched for several minutes before I finally saw a beak move slightly, and I knew they were alive.  I returned again about four days later because one of our neighbor children wanted the eggshells.  By then the chicks were gone from the nest and the momma had apparently deposited the eggshells far away.  Here she is...

I was never able to get a picture of the "broken wing" maneuver.