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.
♦ ²Feeding and General Activity Patterns of a Howler Monkey (Alouatta palliata) Troop Living in a Forest Fragment at Los Tuxtlas, Mexico, Alejandro Estrada, Saúl Juan-Solano, Teresita Ortíz Martínez and Rosamond Coates-Estrada, American Journal of Primatology 48:167-183 (1999)