Julie McCall and Ron Shields answered the first part correctly. Walt's trifecta was photos of an Osprey (above), a Peregrine Falcon and a Bald Eagle, all of which were pushed to the brink of extinction in most of the United States because of the use of DDT. (Thanks, Walt!)
Ron also answered the second part correctly: "It'a a flying fish!!! Actually, it looks like a menhaden or a mossbunker which is high on the osprey's diet."
The mystery, as Randal Sokolik pointed out, was: Where'd it come from ? "Hudson, Hackie, Meadowlands??"
Tomorrow: Nifty photos of Walt's nifty trifecta.