To prepare the mind for medicine, nothing surpasses bird watching—birding, to its active practitioners. Both birding and diagnosis demand and reward many of the same traits. Each vocation brings its world into sharp focus and provides endless variety. To study birds and their migrations is to have one's finger on the pulse of the planet. The ICD-9 and the world's avifauna each contain nearly 10 000 entries—if you include such terms as “accident involving spacecraft” and “diabolical nightjar,” respectively. Birds and infections achieve dazzling and confounding diversity in the tropics. Each may gain latitude and altitude with climate change. Both invite ...