During the 20th century agriculture underwent important changes based on the search for maximum productivity. These have led on the one hand to an important homogenization of the landscape due to the concentration of land and, on the other hand, to the use of a large amount of pesticides and fertilizers in the environment. This change in agricultural management has been linked to the loss of plant and wildlife biodiversity. In the specific case of pesticides, there are significant gaps in the knowledge of their secondary or sub-lethal effects on wildlife. The aim of this study is to evaluate the impact of different agricultural management models, based on the use or not of pesticides, on the reproductive success of the Iberian hare (Lepus granatensis) as a sentinel species of the potential effects that the use of pesticides can have on the wildlife of the Iberian agrarian ecosystems. To carry out this study, pesticide residues were analysed on gastric content of hunted females, from hunting areas free of pesticides (control 1 and 2, n=18) and from others where pesticides are used (treated 1 and treated 2, n=32), to which different reproductive parameters were also analysed. For this last, the ovaries of each individual were weighed, measured and processed for a subsequent follicle and corpora lutea count. Hares from the two pesticide-treated areas showed high prevalence of glyphosate (22.2-31.6%) and in one of these areas also of 2,4-D (12.5%). Fungicides were detected in some individuals (6.6%), and insecticides were not detected. No residues were detected in hares from pesticide-free areas. Hunted females from pesticides-treated areas showed a significantly lower ovarian size and weight than hares from pesticides-free areas. Significant differences were also detected among study areas in the number of atretic follicles, being higher in individuals from one of the pesticide-treated areas. Overall, results showed a higher prevalence of pesticide and lower reproductive condition in females from pesticide-treated areas, which in the long term could have effects at the population level.

Proyecto CONLIEBRE: Efectos de los fitosanitarios en la fauna silvestre: la conservación de la liebre ibérica en la Mancha agrícola (SBPLY/17/180501/000514), financiado por la Junta de Comunidades de Castilla-La Mancha y el Fondo Europeo de Desarrollo Regional y con la colaboración del Grupo Labiana y de la Federación Española de Galgos.

Trabajo presentado por José Manuel Chinchilla Cañaveras para obtener el título de Máster Universitario en Investigación Básicas y Aplicada en Recursos Cinegéticos (MUIBARC).

Peer reviewed