I have been a federal bird bander for nearly 48 years and one of the requirements for obtaining a banding permit is attention to detail. Recently I was working with a fellow bander on a hummingbird banding project in southeastern Arizona. I have worked with hummingbirds for several years and each time I work with these birds I am reminded about the necessary attention to detail that is required. Each time a bird is captured there are a series of measurements that are taken ? length of the wing [wing chord], exposed culmen [length of bill], width and length of rectrices [tail feathers] ? and that is just a partial list. Each of these various measurements and observations serves like a flow chart to allow the bander to determine the age and sex of the various