Juvenile howler monkey and capuchin monkeys interaction - Serra da Capivara

Example of two events of aggressive interaction of capuchin monkeys (Sapajus libidinosus) with howler monkeys (Alouatta caraya).
Serra da Capivara National Park - Brazil
Supplementary Material of paper:
Falótico, T., Mendonça-Furtado, O., Fogaça, M. D., Tokuda, M., Ottoni, E. B., & Verderane, M. P. (2021). Wild robust capuchin monkey interactions with sympatric primates. Primates. doi.org/10.100...

[@PrimateProductions]

Very interesting. Were the capuchins just annoying the howler monkey and curious about him or did they seem to be truly aggressive or attempting to harm him? Was that a juvenile howler monkey or adult? Where was the howler monkey's troop? Why was he all alone?