--s:

I agree that the eggs look precisely like the one in your illustration.
But the bird hatching them (and the one I presumed laid them) doesn't
look anything like either the House or Bewick's Wren nesting in the
birdhouse of which I previously posted a picture.

I caught the wren in flight today (they won't sit still) as it left the birdhouse:

http://dotcomjoe.com/0416b1

And here are a couple of shots from the one nesting behind the container plant (again, very skittish):

http://dotcomjoe.com/0416b2

I'm unable to view the eggs in the birdhouse, so I can't compare the two
nests, but with the eggs in your linked illustration looking suspiciously
like the eggs in the open nest, I wonder whether the Wren learned a trick
or two from a friendly magpie, and lay some of her eggs in this bird's nest
to let her and her mate raise them :-)

~aj