Data for: blood and feather carbon and nitrogen stable isotopes for the Saffron Finch

We measured δ13C and δ15N in blood over a year, and in different feathers from yellow females, yellow males and dull individuals of a Saffron Finch (Sicalis flaveola) population in a private farm in the Central Brazilian savannas. We sampled 195 individuals in seven field samplings between January 2017 and March 2018. The mean blood δ13C values were similar among yellow females, yellow males and dull individuals, indicating that this population of Saffron Finch predominantly accesses similar resources throughout the year, with a predominant C4 signal. Although Saffron Finch is considered a granivorous species, the mean δ15N values found indicate that both adults and juveniles also incorporate in their tissues animal protein.