Scouting for Suburban Philly Christmas Bird Count

This year for the Glenolden Christmas Bird Count I've inherited a 10 mile stretch of the Delaware River downstream from Philly, from the PHL International Airport to Marcus Hook on the Pennsylvania/Delaware state line (see below).

My Glenolden CBC area from Marcus Hook, PA (left) to PHL International Airport (right)

Over the past week, I've scouted out more small urban woodlots, marinas, petrochemical complexes, and abandoned industrial landscapes than I have in a long time.  So far I've found 50 species in my area, and am hoping for more during the actual count on Saturday (though projected rain may hurt).

Abandoned industrial facility, Marcus Hook, PA

So far my biggest take away from scouting--there just aren't as many birds as I would expect for so m much open space.  Is it just a surfeit of exotic vegetation creating bad habitat, or is something else going on?  We hear about declines in bird populations, and it is a bit shocking how thin the bird numbers are.  In a half mile stretch of road near this abandoned complex above, there were only 41 individuals of 12 species--pretty much all urban adapters.  I would have thought there would be more sparrows in all the brush, but it was pretty slim pickings.  

I love this time of. year when I get to explore usually marginal birding areas for potential habitat and lingering migrants or vagrant wintering birds.  So far I've found a lingering (Western) Palm Warbler near the base of the Commondore Berry Bridge and three late Pine Warblers in Marcus Hook.  Hope they stick around for the count on Saturday, and that I can find a few more goodies tucked away here and there in the habitat pockets of Marcus Hook, Chester, Eddystone, Essington, and Tinicum Twp!