Salida de campo a la Cuesta de la Maruquesa, en Valladolid capital, el 21 de mayo de 1950, de la que se anotaron observaciones sobre las siguientes aves: Alectoris rufa (Perdiz roja), Calandrella sp. (Terrera; probablemente Calandrella brachydactyla), Carduelis cannabina (Pardillo común), Corvus corone (Corneja negra), Galerida cristata (Cogujada común), Lullula arborea (Totovía), Melanocorypha calandra (Calandria), Phylloscopus bonelli (Mosquitero papialbo), Pica pica (Urraca), Serinus serinus (Verdecillo) y Sylvia communis (Curruca zarcera)
Field trip to the Cuesta de la Maruquesa, in the city of Valladolid, the 21st of May of 1950, of which there were noted observations of the following birds: Alectoris rufa (Red-leged Partridge), Calandrella sp. (Lark; possibly Calandrella brachydactyla), Carduelis cannabina (Eurasian Linnet), Corvus corone (Carrion Crow), Galerida cristata (Crested Lark), Lullula arborea (Wood Lark), Melanocorypha calandra (Calandria Lark), Phylloscopus bonelli (Bonelli´s Warbler), Pica pica (Black-billed Magpie), Serinus serinus (European Serin) and Sylvia communis (Common Whitethroat)
