Yesterday morning, we had a Black-throated Blue Warbler as well as many
Blackpolls & several American Redstarts.

In the evening, a pair of Common Nighthawks flew overhead, a new yard bird
to us.  

About the same time, we saw a pair of intertwined Black Rat Snakes "oozing"
out of a hollow sycamore bole, head first dangling into thin air.  The
bigger of the two snakes was about 5 ft. long and the lesser was about 4 ft.
long.  When they were almost completely out and it looked like they would
plunge to the ground, they separated, curled over to the trunk and
descended.  About 15 minutes later, the smaller snake climbed back up the
trunk and disappeared completely into the bole.

Were they fighting or mating?

Brian Cassell
Annapolis, MD