Data from: Influence of visual information on sniffing behavior in a routinely trichromatic primate

Most catarrhine primates are considered to be strongly visually oriented
animals, obtaining information about conspecifics and their environment
from a diversity of visual cues. Other sensory modalities may provide
information that is redundant and/or complimentary to visual cues. When
cues from multiple sensory modalities are available, these may reinforce
or suppress each other, as shown in a range of taxa from insects to
humans. In the present study, we tested how the presence and ambiguity of
visual information affects the use of olfactory cues when exploring food
and non-food items in semi-free ranging Barbary macaques at Affenberg
Salem, Germany. In experiment 1, we presented monkeys with pipes
containing food (peanuts, popcorn), non-food (stones, feces) or no items.
The ends of the pipes were either transparent or opaque, and we assessed
whether animals looked, sniffed and/or grabbed into the pipes depending on
visibility of the contents. In experiment 2, we manipulated the visual
appearance of familiar food items (popcorn) with food colorant and scored
if monkeys sniffed at and/or ate the popcorn depending on whether it was
uncolored or dyed. In both experiments, the available visual information
modulated sniffing behavior. Both visual as well as olfactory information
further affected, whether or not monkeys attempted to retrieve the items
from the pipes in experiment 1, while data were insufficient to assess
this in experiment 2. Hence, reliance on the olfactory sense was modulated
by the available visual information, emphasizing the interplay between
different sensory modalities for obtaining information about the
environment.