We will email you so you're the first to know when we launch new features.
While birding east of Portland, Oregon on 4 August 2013, Shawneen Finnegan, Rich Hoyer and I found an odd-plumaged pale swallow in a large mixed group of Tree, Violet-green, Barn, Cliff, Northern Rough-winged and Bank swallows. It was mostly white below and the areas of the upperparts that would typically be dark, were instead pale silvery gray.
I took several photos of the bird and we watched it on and off for nearly 45 minutes. Based on what I could see, I thought it was a hatch-year Bank Swallow. It was smaller than most of the other swallows and by direct comparison it appeared slightly smaller and shorter-winged than a Violet-green Swallow when perched. It spent most of the time perched on the wires with about 200 other swallows, so we got a good feel for its size and proportion. We did see it fly a couple of times. In flight, the shape and proportion seemed to best fit Bank Swallow in my opinion. Rich thought that it might be a Tree Swallow.
I've seen a number of leucistic or at least partially leucistic swallows over the years. They have been either white/or dappled white, or in a couple of cases creamy-tan overall. None displayed this sort of silvery-gray quality. In fact, until recently, I had never seen any species of bird that showed this sort of gray plumage anomaly. Just recently, Cathy Sheeter found and photographed a mostly gray Swainson's Hawk (I believe in Colorado), which had essentially no brown coloration. She shared the images with Jerry Ligouri, who posted them on his blog. http://jerryliguori.blogspot.com/
I've spent quite a bit of time online trying to find references to similarly plumaged swallows and found none. I also couldn't find any references to plumage anomalies that involved darker feathering being replaced by gray feathers. If anyone is aware of a description/explanation of this plumage aberration, I would like to learn more about it.