Data from: Seasonal differences in baseline innate immune function are better explained by environment than annual cycle stage in a year-round breeding tropical songbird

Data was collected at the Amurum Forest Reserve (09°52’N, 08°58’E) which is located at the A.P. Leventis Ornithological Research Institute (APLORI) in Nigeria. Data was collected between January 2014 and February 2016. Birds were caught using mist nets. Data contains individual information of Common Bulbuls Pycnonotus barbatus sampled for blood to quantify indices of innate immunity, including haptoglobin, nitric oxide (NOx) and ovotransferrin concentrations, and haemagglutination and haemolysis.