Drzewińska‐Chańko, J., Włodarczyk, R., Gajewski, A., Rudnicka, K., Dunn, P. O., & Minias, P. (2021). Data from: Immunocompetent birds choose larger breeding colonies. Journal of Animal Ecology The dataset contains three spreadsheets: 1. IgY and NAb - contains data on innate (NAb response) and adaptive (IgY concentrations) immunocompetence of common terns (n = 103) 2. MHC - contains data on the major histocompatibility complex class II gene variation in the common terns (n = 140) 3. TLR - contains data on toll-like receptor gene variation in the common terns (n = 59)