We examined the use and modification of pestles by tufted capuchins (C
ebus apella). In each of two experiments we presented 18 subjects with
an apparatus that held sugarcane along with materials that the animal
s could use as tools. In Experiment 1 we presented the subjects with s
ticks, and in Experiment 2 we presented them with sticks, stones, pape
r towels, and food biscuits. Seven subjects used sticks as pestles to
break down fiber to and squeeze sap from sugarcane in Experiment 1. Fi
ve of them modified sticks for this purpose. In Experiment 2, 10 anima
ls used pestles and sponges, combined tools, and used pestles to mix t
ogether different kinds of food. These results provide further evidenc
e of functional convergence for the use and modification of tools by C
ebus and Pan and are consistent with the view that extractive foraging
is associated with the tool-using and toolmaking behavior of primates
.