Getting photos of any bird’s front and back views really helps with identification and it just accidentally happened with the pair of Northern Rough-winged Swallows (my gallery link), the first photo. Then the next two photos are of different individual Mangrove Swallows (linked to my gallery).
Why is one Mangrove Swallow Blue and the other Green?
“Mangrove Swallows (Tachycineta albilinea) often appear to be different colors—ranging from green to blue—primarily due to feather wear and the interaction of sunlight with their feathers. They have iridescent feathers that reflect light differently depending on their age and the angle of the sun.” ~Wikipedia
¡Pura Vida!
