Attributes / relations provided by
♦ ¹Response of avian nectarivores to the flowering of Aloe marlothii: a nectar oasis during dry South African winters, Craig T. Symes , Susan W. Nicolson and Andrew E. McKechnie, Journal of Ornithology Volume 149, Number 1, 13-22
♦ ²del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona.