Identifying Empidonax Flycatchers - American Birding Association

Sección I. Instrucciones a los Oferentes (IAO).31. Preferencia Nacional .................................................................................................... 29F. Adjudicación del Contrato ........................................................................................ 2932. Criterios de Adjudicación ............................................................................................ 2933. Derecho del Contratante a aceptar cualquier Oferta o a rechazar cualquier o todas lasOfertas .......................................................................................................................... 3034. Notificación de adjudicación y firma del Contrato ...................................................... 3035. Garantía de Cumplimiento ........................................................................................... 3136. Pago de anticipo y Garantía ......................................................................................... 3237. Mediador ...................................................................................................................... 326

E M P I D O N A XF L Y C A T C H E R Stually no visual identification is irrefutable. Remember,too, that, in many instances, nothing is asreliable as hearing a singing or calling Empidonaxflycatcher. And as always: A birder does not have toidentify every bird encountered in the field, andshould always keep an open mind for the oddball.No question about it, Empidonax flycatchers remainone of the great puzzles for the North Americanbirder. These little birds can be simultaneouslyfrustrating and gratifying. Over the years many expertshave contributed their data and knowledge toBirding and other popular press resources. They haveprovided a foundation for field identification. Seekthem out! There is always more to learn.AcknowledgmentsAll of the data reported in this article are from 240specimens of Empidonax flycatchers at the DelawareMuseum of Natural History. I am especiallygrateful to Dr. Jean Wood for allowing access to thespecimens and for tolerating my seemingly randomschedule. Makenzie Goodman and BernieMaster were of great help in transforming my ideasinto intelligible words and phrases. I thank themgreatly for their input.Literature CitedBenson, r.h., and K.L.P. Benson. 1989. The pocket computer: a newtool for identifying eastern Empidonax in the hand. North AmericanBird Bander 14:79–82.cox, c. 2008. identification of north american peeps: a differentapproach to an old problem. Birding 40(4):32–40.crossley, r. 2006. Size, structure, and shorebirds. Birding38(2):68–71.Kaufman, K., and d. Sibley. 2002. The most misidentified birds innorth america. Birding 34:136–145.Lee, c.-T., and a. Birch. 2006. advances in the field identification ofnorth american dowitchers. Birding 38(5):34–42.Lee, c.-T., a. Birch, and T.L. Eubanks. 2008. Field identification ofwestern and Eastern wood-Pewees. Birding 40(5):34–40.whitney, B., and K. Kaufman. 1985a. The Empidonax challenge, Parti: introduction. Birding 17:151–158.whitney, B., and K. Kaufman. 1985b. The Empidonax challenge, Partii: Least, hammond’s, and dusky Flycatchers. Birding 17:277–287.whitney, B., and K. Kaufman. 1986a. The Empidonax challenge,Part iii: “Traill’s” Flycatcher: The alder/willow problem. Birding18:153–159.whitney, B., and K. Kaufman. 1986b. The Empidonax challenge, PartiV: acadian, Yellow-bellied, and western Flycatchers. Birding18:315–327.whitney, B., and K. Kaufman. 1987. The Empidonax challenge, PartV: gray and Buff-breasted Flycatchers. Birding 19:7–15.38B i r d i n g • M a r c h 2 0 0 9