Eur J Wildl Res DOI 10.1007/s10344-006-0045-3 ORIGINAL PAPER Juan Herrero . Alicia García-Serrano . Sergio Couto . Vicente M. Ortuño . Ricardo García-González Diet of wild boar Sus scrofa L. and crop damage in an intensive agroecosystem Received: 7 December 2005 / Accepted: 14 April 2006 # Springer-Verlag 2006 Abstract The Middle Ebro Valley (MEV) is a semiarid area in northeast Iberia where the original riparian ecosystems are almost extinct and were replaced by intensive irrigated agricultural lands. To minimize crop damages and to understand the impact of wild boar on relict riparian ecosystems, a culling program was undertaken from 1994 until 2004. To assess the impact of wild boars, we analyzed stomach contents and surveyed crop damage. In the MEV, wild boars feed mainly on crops, particularly, maize. Other elements of the diet that are of agricultural origin include wheat, barley, and alfalfa, which are the alternatives to maize in the period between harvest and seeding, which is the basis of seasonal changes in diet. Results indicate that wild boar actively selected maize crops and consumed wheat in proportion to its abundance; barley and alfalfa fields were damaged less than expected based on their abundance. In the MEV, the wild boar population is limited by the availability of shelter areas found in the scarce riparian ecosystems, which do not provide important food items for this population. We conclude that in the region of this study, wild boars are not a significant threat to the flora and fauna of riparian ecosystems, although as these habitats are restored and areas are protected, the carrying capacity for wild boars might increase. Keywords Maize . Wetlands . Protected areas . Limiting factor Introduction The wild boar is a large mammal that has one of the broadest geographic distributions (Groves 1991). The species can occupy a wide range of environments, including semideserts, wetlands, high mountain environ- ments, and forest ecosystems (d’Huart 1991). After the expansion of the wild boars’ distribution in Europe, which began in the 1960s (Tellería and Sáez-Royuela 1986), the species has occupied agroecosystems where populations have exhibited different levels of dependence on agricul- tural products for food (Gérard et al. 1991). Damages to crops have led to the development of different avoidance techniques (culling, supplemental feeding, and electrical fencing) and some evaluations of these techniques (Geisser and Heinz-Ulrich 2004). As a generalist omnivore, the wild boar can feed on a wide variety of foods for which the availability in space and time is not constant. As such, the wild boar’ s diet is a product of the environmental characteristics of the area in which it lives and the resources found there. As a result, wild boars can have an impact on its environment, such as causing damages to agricultural land (Leranoz 1983), pastures (Alexiou 1983), or impacts on forest regeneration (Groot Bruinderink and Hazebroek 1996), predation (Pavlov et al. 1981), consumption of forest fruits (Durio et al. 1995; Herrero et al. 2004a), and consumption of carrion (Herrero and Fernández de Luco 2002). In this study, we determined the annual and seasonal diet of a wild boar population and the damage it inflicted on crops in an intensive irrigated agroecosystem in northeastern Spain. We evaluated the importance of riparian habitats as sources of food because of the J. Herrero Department of Ecology, Alcalá University, Alcalá de Henares, Madrid, 28871, Spain e-mail: egasl@arrakis.es J. Herrero . S. Couto . R. García-González Pyrenean Institute for Ecology (IPE-CSIC), P.O. Box 64 Jaca, 22700, Spain e-mail: rgarciag@ipe.csic.es J. Herrero (*) . A. García-Serrano . S. Couto EGA, Wildlife Consultants, Sierra de Vicort, 31, 1°A, Zaragoza, 50003, Spain e-mail: juan.herrero@uah.es Tel.: +34-918-856401 V. M. Ortuño Department of Animal Biology and Physical Anthropology, Alcalá University, Alcalá de Henares, Madrid, 28871, Spain e-mail: vicente.ortuno@uah.es