Ted Parker died in August 1993 at age 40, in an airplane crash while conducting aerial assessments of threatened habitats in Ecuador. Parker's two decades of work in the Neotropics strongly influenced many field ornithologists. Although he published numerous papers, the majority of his data and many of his ideas were never published. Through example, conversations, and extensive correspondence, he directly influenced the methodology and conceptual orientation of many others. We summarize his major discoveries and highlight his primary themes, particularly the importance of knowledge of (a) bird vocalizations for faunal surveys, and (b) voice, habitat, and foraging behavior for systematics. His Rapid Assessment Program, sponsored by Conservation International, was a landmark approach for conservation biology. Resumen. Ted Parker muri6 en agosto de 1993, a la edad de 40 afios, en un accidente de avion mientras realizaba una evaluacion aerea de los habitats amenazados en el Ecuador. Las dos decadas de trabajo del Sr. Parker en el Neotr6pico influenciaron fuertemente a muchos ornit61ogos de campo. Aunque el public6 numerosos articulos cientificos, la mayoria de sus datos y muchas de sus ideas nunca fueron publicadas. Mediante su ejemplo, sus conversaciones, y su extensa correspondencia, 61 influenci6 directamente la metodologia y orientaci6n conceptual de muchos otros. Resumimos sus mayores descubrimientos y resaltamos sus temas primarios, en particular la importancia del conocimiento de (a) las vocalizaciones de las aves en los levantamientos de fauna, y (b) la voz, el habitat y el comportamiento alimentario en la sistema~tica. Su Programa de Evaluaci6n Ra*pida, patrocinado por Conservation International, marc6 un hito en la manera de enfocar la biologia de la conservaci6n. * 'Walking through South American forests with Ted Parker, I found myself agreeing with the superlative opinions I had heard expressed about him. Of all the highly skilled field ornithologists I have accompanied, he was the most impressive. (Gell-Mann 1994:334) Ted Parker died after the plane in which he was conducting aerial reconnaissance for Conservation International crashed in a remote area in western Ecuador on 3 August 1993. Three others died in the accident, including botanist Alwyn Gentry (see Hurlbert 1994) and Ecuadorian conservationist Eduardo Aspiazu. Parker's death was a tremendous personal tragedy to his family, his fiancee Jaqueline Goerck, and legions of friends. His death also was a devastating tragedy for Neotropical ornithology and conservation. Our goal is to outline his major accomplishments and to show how he influenced research on Neotropical birds. Because we focus on his scientific contributions, we provide only minimal details on his personal background. For more comprehensive information, see the tributes and memorials published after his death (e.g., Emanuel 1993; Kaufman 1993; Myers 1993; O'Neill 1993; Remsen 1993; Schmidt-Lynch 1993; Stevens 1993; Zimmer 1993; Anon. 1994; Forsyth 1994; Jammes 1994; Collar 1995; Foster 1995; Muth 1995; Schulenberg 1995; Bates and Schulenberg 1997; Robbins et al. 1997). An issue of Bird Conservation International (Schulenberg and Collar 1995), with 15 research papers in his honor, was dedicated to his memory. During his childhood in Lancaster, Pennsylvania, Ted showed an exceptional aptitude for learning natural history information. Encouraged in his studies by his parents and brother B Ianford, and assisted by the local bird-watching community (especially Harold Morrin), Ted had