Michael Norris sought help with the id of a juvenile cormorant.
Juvenile cormorants can be quite difficult to id, but from the description
given I'm pretty confident that this one is a Black-faced Cormorant. The black
cap extending below the eye pretty well seals it - Pieds always have a clear
white gap between the black crown and the eye. The dusky throat and upper neck
are also typical of juv Black-faced.
However, the best features to distinguish these 2 species are structural - the
shape of the bill and forehead. Black-faced Cormorant has a rather narrow bill
which slopes upwards at the base to meet the steep forehead. The bill of the
Pied Cormorant is longer and deeper and rather uniform in depth for its entire
length. The forehead is lower and flatter giving an almost reptilian profile.
Another really good feature is the shape of the boundary between the feathered
and bare parts of the face. In the Black-faced it forms a clear zig-zag from
immediately below the eye posteriorly to the gape which is well behind the eye,
then forward to the lower mandible then posteriorly again to the posterior
point of the bare gular pouch under the chin. In Pied Cormorant this boundary
is far less angular with just a modest indentation at the gape.
Peter Menkhorst
==============================www.birding-aus.org
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