Attributes / relations provided by
♦ ¹del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona.
♦ ²Tscharntke, T. 1992. Cascade effects among four trophic levels: bird predation on galls affects density-dependent parasitism. Ecology 73:1689–1698