Paul Slud, Associate Curator of Birds at the National Museum of Natural History (Smithsonian Institution) from 1964 to 1983 and Elective Member of the AOU, died on 20 February 2006 at age 87. Paul's work concerned the distribution and general ecology of birds of Costa Rica, the relations of faunal components to climate and vegetation, and methods for broad faunal comparisons. As a small boy in New York City, his life-long interest in nature was fostered by trips to the Bronx Zoo and by reading stories about exotic “jungles.” After taking an eclectic mix of courses at City College of New York, he received a degree in geography, and in 1948 he took Arthur Allen's ornithology course at Cornell University. He chose to study a vertebrate group exhibiting song and bright plumage rather than something one would find “under a rock.” Most of his first three years as a graduate student at the University of Michigan were spent in Costa Rica, where he collected specimens for the Museum of Zoology. He also worked briefly for the Museo Nacional de Costa Rica. In the field, he was a skilled observer and an expert in identification of bird vocalizations. During his field and museum work, Paul began an extended correspondence with Alexander Wetmore, whose expertise in species-level taxonomy of Panamanian birds helped Paul formalize his own observations on subspecific variation in Costa Rican birds. In turn, he answered Wetmore's questions about details of distribution of Panamanian species in adjacent Costa Rica. Paul's Ph.D. thesis work at Finca “La Selva” was a practical application of his conviction that a series of well-chosen site studies was the best basis for faunal comparisons. In that work, he took Ernst Mayr to task for his ideas about a northern origin of the Neotropical avifauna and the competitive superiority of oscine passerine birds over the suboscines in the New World.

Paul managed to live on grants while completing his book on Costa Rican birds. In the early 1960s, he held a one-year appointment at the University of Florida, a salaried Research Fellowship at AMNH, and an NSF grant for further field work. In addition, a Guggenheim Fellowship supported his study on birds of Cocos Island, Costa Rica. In total, he spent more than eight years of field study in Costa Rica, often living under primitive conditions. He lamented that field stations were “usually in the wrong place.”

Paul had a knack for conveying the essence of his field experiences as well as facts and hypotheses. A good example is a paper published in The Condor in 1958, in which he explored the taxonomic implications of his discovery of two geographically distinct songs in the Nightingale Wren that did not conform to the limits of known subspecies. The description of his field work that led to this epiphany is a classic. It also illustrates his dedication to ecology rather than traditional museum studies, in that he left it to others to discover the morphological differentiation associated with the song types and to recommend the recognition of two species.

One of Paul's early discoveries in comparative faunistics was a remarkable correspondence between the ratio of suboscine to oscine birds at different Neotropical sites, and their relation to his detailed descriptions of habitats at each site and to the Holdridge maps of World Plant Formations. For example, higher ratios predicted wetter and more complex forest. In an attempt to test this idea worldwide and to evaluate other kinds of ratios used by others for faunal comparisons, he embarked on a quest for meaning in ever more complex ratios that culminated in his “Geographic and Climatic Relationships of Avifaunas with Special Reference to Comparative Distribution in the Neotropics” in 1980. Unfortunately, the emphasis on ratios often overshadowed his insightful discussions of faunal comparisons, faunal origins and evolution, island biogeography, source pools, ecological competition, the importance of migrants, and other topics.

Although Paul made little use of the collections at NMNH for systematic studies, he was a stickler for the details of curatorial practice to an extent that drove the technical staff to distraction. However, among other improvements, he initiated expansion of the collections to a third tier of cases to alleviate overcrowding of specimens and gave each case a unique designation such that new cases could be added without changing existing designations. He then had a booklet prepared that gave the case location for each avian genus, alphabetically listed.

Paul knew the Mozart operas by heart, read extensively, and enjoyed local bird watching and stamp collecting among other interests. He is survived by his wife, Barbara, two children, Michael and Martha, and four grandchildren.