espanolEn este estudio se muestra documentacion inedita referente a una queja presentada al Gobierno de Espana en 1933 por la Federacion Iberica de Sociedades Protectoras de Animales y Plantas, por el aparente incumplimiento de la Convencion Internacional para la Proteccion de las Aves (1902). El motivo era la caza con metodos de captura no selectivos (redes y liga), que estaban prohibidos por dicho tratado, pero que el Gobierno de Espana, en 1929, habia autorizado en determinados casos. Este tipo de caza pudo contribuir a la eliminacion de grandes cantidades de paseriformes, algunos protegidos por ley. Segun la documentacion estudiada, la queja de esta federacion fue impulsada por una carta remitida por Leon Pittet, presidente del Comite National Suisse pour la Protection des Oiseaux. Estos hechos ponen de relieve las relaciones existentes entre las organizaciones europeas, cuya finalidad era la conservacion de las aves, y ciertas asociaciones espanolas, entre cuyos objetivos figuraban tambien la defensa de los paseriformes, en una epoca en la que aun no se habia constituido la Sociedad Espanola de Ornitologia. Ademas, indican que la Convencion de 1902 tuvo algunas consecuencias practicas positivas, que finalmente disminuyeron por la presion ejercida desde importantes sectores cinegeticos de Espana. El caso que se presenta aqui pone de manifiesto que el conflicto que existe actualmente en el pais entre determinados metodos de caza y las leyes para la conservacion de las aves se remonta al menos a la primera mitad del siglo XX. EnglishHunting passerines with non–selective trapping methods was a source of conflict in Spain as far back as 1933.— We here show unpublished documentation regarding a complaint presented to the Spanish Government by the Iberian Federation of Societies for the Protection of Animals and Plants in 1933. This complaint concerned apparent non–compliance with the International Convention for the Protection of Birds (1902). The reason was hunting with non–selective trapping methods (nets and birdlime) that were prohibited by the convention but authorized in certain cases by the Spanish Government in 1929. Such hunting could have contributed to the elimination of large numbers of passerines, some protected by law. According to the documentation studied, the complaint from this Iberian Federation was triggered by a letter sent by Leon Pittet, president of the Comite National Suisse pour la Protection des Oiseaux. This event emphasizes the relationships between European organizations whose purpose was the conservation of birds, and certain Spanish associations whose objectives included the defense of passerines in the years before the Spanish Ornithological Society was created. In addition, it indicates that the 1902 Convention had some positive practical consequences, although these later decreased due to pressure from important hunting sectors in Spain. The case presented here shows that the current conflict in Spain between the use of certain hunting methods and legislation for the conservation of birds dates back at least to the first half of the twentieth century.