Long-tailed Duck still present Lagerman Reservoir: Boulder County

[Bryan Guarente]

The Long-tailed Duck reported originally by Bill Schmoker was still present today as of 3:00pm.  I spent more time today studying this bird and found out that I can't tell what age or sex it is.  I do know that it isn't an adult male, but other than that, due to lack of illustrations in the Sibley Field Guide I had on me, I couldn't devise what sex or age this bird was.  Are there any resources out there to help out with this or am I left with "Long-tailed Duck (not adult male)"?

Thanks for any help in advance.

Directions to Lagerman Reservoir can be found here:
http://www.coloradocountybirding.com/county/bird_a_county.php?name=Boulder#362

 

Bryan Guarente
Instructional Designer
The COMET Program
University Corporation for Atmospheric Research
Boulder, CO