Hello jbtaylor,
I can't pick any as the best. Each one is a different value. You have very nice compositions of these birds in their most natural state and environment. If you collect many more such as these shots then one day you'll have a great lake birds collection. Would make a great book or posters, I guess!
Lots of nice details; like the feathers being lifted by the wind; picking food out of the waters; good light showing each detail of the feathers and nicely sharp too...
Thanks for sharing. And that lens with the converter seems to make things easy for you while shooting wild creatures, as they all are very natural and undisturbed. Must be a relaxing experience! When I'm not 'building scarecrows to scare the illegal construction erectors' in shape of contractors around my residence I should do some wildlife shooting myself. I need soothing my nerves too...
Yildiz