Here's a juvenile Common Loon still in it's first year winter coat. I didn't know what it was when we found her/him on the beach but I had a sense it was a juvenile because it didn't exhibit much fear or agressive behaviour. I was able to approach quite close. Near Point Dume in Malibu, CA.
E-5 and 50-200 mm lens at 200 mm, ISO 200, f/10, 1/500 sec.