This is the final scene in my last dragonfly video ( vimeo.com/51102796 ) a zoomed out view across the lake from where I got the dragonflies. It is almost not noticeable in the clip but looking closer to the right there is a pole with signs in the water. When I zoomed in these two birds appeared, one sitting on the top and the other standing in the water at the pole opening the wings later swimming to the right.
Enlarged clips in Sony Vegas at the end in this video.
A search on the net may indicate perhaps Skarv or (Great) Cormorant type?