Electronic Supplementary Material, Biology Letters Genetic color polymorphism is associated with avian malaria infections Laura Gangoso, Rafael Gutiérrez-López, Josué Martínez-de la Puente, Jordi Figuerola • Methods: Extended methods on DNA extraction and blood parasites identification • Methods: Extended statistical analyses. Random sampling approach and R code • Results: Table S1: detailed information on the blood parasite lineages found in this study Methods: DNA extraction and blood parasites identification Genomic DNA was isolated from birds’ blood samples using the semi-automatic Maxwell®16 LEV system Research kit (Promega, Madison, WI) (Gutiérrez-López et al. 2015). To determine the prevalence and linage identity of blood parasites, a fragment of the mitochondrial cytochrome b gene of Plasmodium, Haemoproteus, and Leucocytozoon parasites was amplified following Hellgren et al. (2004). This procedure is based on a first PCR using primers HaemNFI (5′- CATATATTAAGAGAAITATGGAG-3′) and HaemNR3 (5′- ATAGAAAGATAAGAAATACCATTC-3′). A nested PCR were used to amplify Haemoproteus/Plasmodium parasites with primers HaemF (5′- ATGGTGCTTTCGATATATGCATG-3′) and HaemR2 (5′- GCATTATCTGGATGTGATAATGGT-3′), while primers HaemFL (5′- ATGGTGTTTTAGATACTTACATT-3′) and HaemR2L (5′-