Effects of sex and sampling site on the relative proportion of pesticides in uropygial gland secretions of European Blackbirds ( <i>Turdus merula</i> )

Dichlorodiphenyltrichloroethane (DDT) is a pesticide that was commonly used for decades worldwide. The use of DDT banned in the 1970s and 1980s Europe because its high toxicity persistence environment, bioaccumulation living organisms biomagnification through food webs. However, monitoring using both invasive non-invasive methods has routinely reported occurrence metabolites such as dichlorodiphenyldichloroethylene (DDE) wild birds, providing valuable information about exposure to pesticides potential differences between species over time. Here, we analysed relative proportion DDE uropygial gland secretions European Blackbirds Turdus merula from two localities southern Spain. Given negative effects this pollutant on animal immunity, also tested associations prevalence haemosporidians their secretions. Relative proportions varied sampling sites were higher females than males, regardless age. In spite immunosuppressive effect DDE, haemosporidian infection not associated with presence.