Among the more challenging tasks for bird banders is aging and sexing birds with speed and precision in the field. North American bird banders use several references and accumulated experience to do this in an efficient manner. One of the most important resources used by banders across North America is the Identification Guide to North American Birds by Peter Pyle (Pyle 2008). While an essential tool for ornithologists, the Pyle book cannot completely describe, in detail, every variation seen across such a vast scope of coverage.

Here in the Pacific Northwest we have discovered that there is a lot more to understand about aging Song Sparrows, Bewick’s Wrens, Brown Creepers, and Spotted Towhees, and some lesser information to gather about other species that we see regularly and in great numbers. Based on observations in the field over several years, we feel that we are able to develop more detailed and accurate criteria for aging and sexing these challenging birds in the hand. One of the areas we intend to improve the practice of aging and sexing birds is by quantifying feather and soft part color and feather wear to better increase accuracy. Over the course of our three year study, we feel that we can supplement what Pyle shares to make micro‐aging and sexing birds quicker and more efficient.

This project is using mist nets across the south Puget Trough to capture, mark, and recapture birds of known age, and is using a special photgraphic process to quantify the color shift that happens as feathers age and wear.  In doing this, we hope to be able to contribute to and  expand the criteria that Pyle's research outlines in his book.