Yesterday at Kennard Elementary School in Centreville, my birding class 
cleaned out the bluebird nesting boxes.  There are 8 nesting boxes around 
the school and the field beside it.  Last year, we had one bluebird and one 
tree swallow in the 4 boxes that we put up.  One of the teachers put up 4 
additional nesting boxes that I did not check during the season.  These 
boxes were the ones with an oval opening and the front slants inward toward 
the post.  When we cleaned these boxes this year, we found 3 nests made 
almost entirely of sticks with little, if any, fine material such as grass 
or moss.  Of course, this material could have decomposed during the year.  I 
do not have a bird's nest book, but I did some research on the internet and 
in the Birder's Handbook.  I believe that a Carolina Wren was the nester.

Can anyone confirm/deny my guess as to the nester?
Many thanks.

Jim Wilson
Queenstown