It’s Sunday, which means we have a themed batch of bird photos from biologist John Avise. His text and IDs are indented, and you can enlarge the photos by clicking on them.
Two of my earlier WEIT posts highlighted blues and reds in avian plumages (see “Blue Birds in North America” and “Red Feathers”). This week, green is the featured color. Green is an uncommon hue in North American birds, so I had to dig hard to find suitable examples from my photo collection. Green colors in bird plumages usually stem from blue structural features of feathers in combination with yellow carotenoid pigments. In many species, the green is displayed equally by both sexes, thus suggesting that camouflage in green foliage may be adaptive and favored by natural selection. [Given the ubiquity of green vegetation, I’m actually surprised there aren’t many more green birds!]. But in several duck species with green feathers, drakes are much brighter than hens, so in these cases sexual selection surely is involved. The state where each photo was taken is shown in parentheses.
Allen’s Hummingbird, Selasphorus sasin (California):
Anna’s Hummingbird, Calypte anna (California):
Violet-green Swallow, Tachycineta thalassina (California):
Orange-crowned Warbler, Vermivora celata (California):
Green-tailed Towhee, Pipilo chlorurus (Arizona):
Green Jay, Cyanocorax yncas (Texas):
Green Heron, Butorides virescens (California):
Monk Parakeet, Mylopsitta monachus (Florida, introduced):
Red-crowned Parrot or Amazon, Amazona viridigenalis (California, introduced):
Yellow-headed Parrot or Amazon, Amazona oratrix (California, introduced):
Green-winged Teal, Anas crecca (California):
Northern Shoveler, Anas clypeata (California):
Mallard, Anas platyrhynchos (California):
Mallard head portrait: