High prevalence of parent ro Ro

enerife, Plastics have brought important benefits to humanity such as health, safety, energy savings or material conservation (Andrady and Neal, 2009), but they have also brought concerns about their accumulation in the environment and transfer of chemicals to wild-life and humans (Thompson et al., 2009). Important amounts of by seabirds has been widely recorded, being Procellariiformes the most affected order (more than 63 % of species; Laist, 1997). Despite the voluminous information on ingested plastic debris by adults across the world (e.g. Colabuono et al., 2009; Hyrenbach et al., 2009; van Franeker et al., 2011; Yamashita et al., 2011), the transfer of plastic debris from parents to fledglings has been studied in a limited number of species, mainly from the Pacific Ocean (Hutton et al., 2008; Young et al., 2009; Bester et al., 2010; Carey, 2011; see also Copello et al., 2008). Monitoring the incidence of plastic ingestion is crucial to assess temporal trends of marine plastic debris and their potential effects fledglings in the Canary Islands, North Atlantic Ocean, as well as po-tential differences between sexes, years and date of fledging. Fur-thermore, we assess the effect of plastics on the fitness of fledglings measured as body condition and body size indices. Final-ly, we provide a description of plastic items, including size, mass, color, and type. During their first flights to the sea, many Cory’s shearwater fledglings become disoriented and end up stranded by artificial lights on Tenerife, the largest island of the Canary Islands (Rodríguez diff ns