LBJ

Day 100: You'll probably never hear a birder refer to a Steller's Jay (Cyanocitta stelleri) as an "LBJ," the birding parlance for "little brown job," although that's an accurate description of the colour if not the size. Yep, you heard right: Steller's Jays are brown. For that matter, so are Blue Jays, Bluebirds, Lazuli Buntings or any of the other birds we perceive as blue. The fact is that blue pigmentation does not exist in birds, but feathers may appear blue as a product of structural colouration, i.e., the way the feather reflects light. This phenomenon is more readily apparent in hummingbirds. When viewed at one angle, the males' heads or throat patches may appear bright red, but at a slightly different angle, may look dark or black. This change is due to the way light waves interact with microscopic layers within the feather structure. Some wavelengths pass through the feather and others are reflected back to the observer's eye. This same principle causes Steller's Jay to look blue to us.