The first time I took photos of tree swallows with my longer lens, I found out what they were and that they had blue wings. You can’t really see the color in the sun as they are speeding past you.
Today, I started to use a higher shutter speed. The one I would have known to use if I had listened to the bird photography tutorials. 🙂 And I managed to photograph some with their wings spread open! Beautiful!
More Information on Tree Swallows: Audubon