My perception with screech owls in PG County, even in areas where they are 
still located, is that they're becoming increasingly uncommon, if not 
rare.  After looking pretty thoroughly this year in appropriate areas of 
four Atlas blocks to try and "fill in the blanks", it seems like they are 
absent from all of these PG areas.  I failed to locate screech owls in any 
any new blocks, or or new quarterblocks in blocks where they have been 
found already (i.e., Bristol SW).

This year I didn't observe any screech owls in the Jug Bay area until July 
12, when (only) one was heard calling on a rainy eve at dusk.  I presume 
it was a post-breeding dispersing individual.  This weekend, I found a 
fresh wing feather from a screech owl in my yard on Sunday.  I am not sure 
if the feather is from an adult or HY individual, but I think it is 
another dispersing individual, and could be the same one I heard in July.

As for swamp sparrow and range, I don't know its range but I understand 
that there are several areas along the Patuxent where swamp sparrows have 
been observed singing on territory during this year's breeding season, 
including Jug Bay (Bristol SW).  Jug Bay was the northern most location I 
have heard of.

Cheers-
Jeff Shenot
Croom MD