I participated in the DC CBC today, too, and birded the Arboretum with
Ottavio Janni, Sam Dotson, and Rob Hilton.  The first half of the
morning was pretty slow - apparently it took the birds a while to warm
up.  But in the late morning we found a few good birds including 1 and
possibly 2 ORANGE-CROWNED WARBLERS, a PURPLE FINCH (flyover), 2
RED-BREASTED NUTHATCHES, and a CHIPPING SPARROW.

This O-c warbler, the one that Bob Ringler found at Anacostia Park, and
the one that Robert Steele saw at the FDR memorial earlier in the week
means that there are at least 3 Orange-crowneds in the District now.  It
could be 4 as we had 2 separate sightings about 1/10th mile from each
other and the birds looked a little different from each other (but that
could have been a function of the viewing conditions).  Since we can't
be sure if it was 1 or 2 birds, we're only sticking with 1 bird for
sure.

Good birding,
Paul Pisano
Arlington, VA