This study is an investigation of specialized knowledge of birds (bāhendayal) among speakers of the Mamasani dialect of Southern Luri (SL), an Indo-European language with approximately one million speakers in southwestern Iran. The author provides a description of bird physiology and an inventory of cognitive distinctions that speakers use to differentiate bird types. A comprehensive taxonomy of bird knowledge in Southern Luri is presented in a diagram of bird families followed by a semantically organized list of the 84 terms for bird types found in the language, along with the meanings of these terms. Farsi, English, and scientific labels accompany descriptive notes.