Registration for Tracy Aviary's field ornithology class begins at 10 a.m. today at the aviary. The class is an in-depth look at the bird world and cover topics in basic ornithology (the study of birds) as well as field identification of most of the birds found in northern Utah. It meets one day each week for two hours March 19 to June 4 at the Sugarhouse Garden Center. Cost is $40 for aviary members and $45 for non-members, which includes materials.