Boletín de la RSEHN. Sección Biológica

En este estudio se documentan las especies de aves que han provocado daños agrícolas en Extremadura (suroeste de España) durante los siglos XVI al XIX. Como fuentes documentales se han utilizado los Libros de Acuerdos de más de 200 ayuntamientos de esta región y de su entorno histórico-geográfico. A partir del análisis de los nombres vernáculos empleados en los Acuerdos, las especies encontradas pueden encuadrarse en ocho familias (Passeridae, Columbidae, Corvidae, Alaudidae, Phasianidae, Emberizidae, Turdidae y Gruidae), deduciéndose la participación de entre 13 y 16 géneros de aves. Al cuantificar su importancia relativa destacan en primer lugar los gorriones, que protagonizan aproximadamente el 70% del total de los Acuerdos, mientras que el resto de familias aparecen con frecuencias inferiores al 10%. En conjunto, los paseriformes han sido los protagonistas principales. Los taxones que no pertenecen a dicho orden presentan ciertas particularidades por su procedencia, por los cultivos afectados, por causar daños indirectos o por los procedimientos utilizados en su control. Además, se analiza la ausencia de los Sturnidae y la escasa presencia de otras aves, y se comentan algunos Acuerdos que tienen interés porque aluden a plagas en diferentes regiones españolas, tratan cuestiones cinegéticas o reflejan, en el ámbito municipal, el surgimiento de las primeras normas para la protección de la avifauna insectívora. Por último, se ha subrayado la información susceptible de incrementar los conocimientos sobre la distribución de determinadas especies en el periodo estudiado.

In this study we document the bird species that have caused crop damage in the region of Extremadura (southwestern Spain) from the 16th to the 19th century. The Books of Municipal Agreements of more than 200 municipalities from Extremadura and their historical-geographical surrounding were used as documentary sources (more than a million pages). From the analysis of the vernacular names used in the agreements, the bird species involved can fit into eight families (Tables I and II): Passeridae, Columbidae, Corvidae, Alaudidae, Phasianidae, Emberizidae, Turdidae and Gruidae. With respect to the taxonomic distribution (Table I), data suggested the involvement of 13-16 genera of birds in agricultural damage (sure genera: Passer, Columba, Cyanopica, Pica, Corvus, Galerida, Alauda, Gallus, Alectoris, Coturnix, Emberiza, Turdus and Grus; probable genera: Petronia, Pyrrhocorax and Melanocorypha), but with a very heterogeneous economic impact. When their relative importance was quantified (Fig. 1), sparrows were ranked the first with 68% of the total number of agreements. Far behind, the Columbidae were in the second place with a 6%, and the Corvidae in the third place with a 5.4%. By contrast, the families Emberizidae, Turdidae and Gruidae represented each less than 1%. These results overall showed that the passerines were by far the main protagonists. However, taxa not included in this order also presented some interesting peculiarities, either due to their origin (partially or totally domestic), the crops affected, the occurrence of indirect damages or the procedures used for control. There also was evidence that during the 18th and 19th centuries a greater taxonomic diversity was documented (Table II). Some observations about bird species with no agricultural relevance in Extremadura were made because of their ornithological interest, their pest status in other Spanish regions, their hunting importance or because they reflected, at the municipality level, the origin of the first national and international laws for the protection of insectivorous birds in the second half of the 19th century. We stressed the absence of any reference to agricultural damages produced by the Sturnidae family and the scarce presence of other families (Turdidae and Gruidade), suggesting some possible explanations. Finally, we highlighted the information likely to increase our knowledge about the distribution of certain bird species in the studied period.