Several good suggestions came in regarding the mystery bird - Killdeer,
Quail, Turtle - but no one won the Grand Prize.

The answer:  NORTHERN FLICKER

By the time I reached the home the day after getting the call, the home
owner had solved the mystery - the bird had come to the nest while he was
near the garden.  When on the nest, the Flicker can entirely disappear from
view.  Most of the time she keeps her head high enough to see out, and hence
the top of her head and her bill are visible.  She will return to the nest
while the gardener is working, but is reluctant to do so when strangers
(like me) are in the vicinity.  I have documentary photos of the garden and
the nest and the eggs.  This week I will return to the site to try for a
photo of the bird on the nest.

Has anyone heard of ground-nesting behavior of woodpeckers?  Talbot County
still does have a few trees, despite the heavy development pressures of our
region.  It's not as if this bird needs to make a 'statement' about loss of
suitable nesting habitat.

Les Roslund

Talbot County
Easton MD 21601