Hi Tweets,
I'd suggest that if you're in doubt about a cormorant on which you can see
few distinguishing marks, look at the tail both in flight and perched.
Proportionately, Brandt's Cormorant Phalacrocorax penicillatus has the
shortest, Pelagic Comorant P. pelagicus the longest and Double-crested
Cormorant P. auritus somewhere in between.
In flight, besides typically carrying their necks at or slightly below the
horizontal, both Brandt's and Pelagic have a loon/grebe-like hump-backed
profile rarely shown by Double-crested.
Michael Price
Vancouver BC Canada
mprice at mindlink.net