Thursday, May 17, 2007
Seven years ago, I moved into a house in an old (for this sun belt city) subdivision. One of the big attractions to the place is the large, L-shaped patio which is abundantly shaded by two very large non-bearing mulberry trees. Once established, I hung a bird feeder and suet block to see what birds might come around.
Absent a snow storm to push a bit of variety down from some nearby foothills, I mostly see English sparrows, house finches, mourning doves, the occasional rock dove, and, somewhat to my surprise, white-winged doves. I grew up in areas with white-wings but this is at least a couple of hundred miles north of what I knew as their normal range (although the linked page describes them as having been observed as far north as Alaska!). Although I hadn't seen a white-wing up here in twenty years of casual observation, they seem well established. Further, the number of white-wings around town seems to be generally increasing. More interesting still is the fact that over the years a number of the doves on my feeder have made it a habit to spend the winter here. Most northern dove hunters are familiar with the phenomena of the first little cool front in September sending every dove around winging south for Mexico. This trend ought to be even more pronounced with white-wings, as they are a more tropical bird than the mourning doves. However, while the occasional mourning dove will spend the winter, I have a dozen or more white-wings year round.
I have read that the white-wing dove population in Texas has shifted from the lower Rio Grande Valley north to Austin, San Antonio, and other urban environs where they find the trees for roosting and nesting that have mostly gone away as south Texas brush is removed to create fields. I'm not aware of any similar pressure which would cause the birds to head north out here farther west. Regardless, the white-wings have apparently discovered another urban niche and are busily filling it. I have to say I'm pleased with the prospect. Any native species, especially one which not widespread in the U.S., expanding its range seems like a pretty good thing.
Perhaps just as exciting, this spring an Inca dove visited for a bit- the first time I've seen one of those little guys so far north in over twenty years of living here. Maybe global warming is sending these border birds north. If so, I eagerly await the first jaguar sighting in the southern Sangre de Cristos.