Thanks for the detailed reply.
Good point about specific location. It was at Centennial Lake, in 
the deep end. (Closer to the north shore than the south, and out 
from approximately where the path from the north parking lot meets 
the path around the lake.)

June Tveekrem
Columbia, Howard Co, MD
tweekiebird AT toadmail DOT com


Maurice Barnhill wrote:

I took the liberty of changing the subject line because after about
a half hour of work I am not certain of the identity of this bird.
The white line bordering the gular patch on that bird is the
textbook mark for Neotropic Cormorant, but there are some things
that bother me.

First, the line is uncharacteristically narrow and doesn't show the
usual backward point. Second, to my somewhat undereducated eye the
bird looks to me to have the general head size/shape of a
Double-crested Cormorant. The issues are 1) how much variation in
the white there is in Neotropic; 2) whether the bird possibly has
some immature plumage left; and 3) if the bird is in changing
plumage whether there is ever a narrow white line in the
corresponding plumage of Double-crested Cormorant.

A look through some of the pictures found from a Google search found
birds that look like this one that were identified as Double-crested
and several birds from the range of Neotropic, identified as
Neotropic, that also looked rather similar. I will be very
interested in the comments this bird attracts. You might want to
give a more specific location in case anyone wishes to look for it.
If no one more knowledgeable than I gives a good argument for the
identity of the bird, it might be worthwhile to get the pictures
looked at by someone who regularly sees both species together.