Nikkor 200-500 VR/TC 14 III @600mm, f8, ISO 1250; Nikon D750
crop (APS-H), Amazon
The black-mantled tamarins feed on anything they can find in the forest
from insects, fruits, nectar to seeds. They enjoy https://tinyurl.com/theTreeSap given a chance.
The large canines are the reason why they can’t gouge their own holes into the bark
with their lower teeth like the marmosets do (it involves up and down movement).