Social learning data in a foraging setting for Heliconius erato

Insects may acquire social information by active communication and through
inadvertent social cues. In a foraging setting, the latter may indicate
the presence and quality of resources. Although social learning in
foraging contexts is prevalent in eusocial species, this behaviour has
been hypothesised to also exist between conspecifics in non-social species
with sophisticated behaviours, including Heliconius butterflies.
Heliconius are the only butterfly genus with active pollen feeding, a
dietary innovation associated with a specialised, spatially faithful
foraging behaviour known as trap-lining. Long-standing hypotheses suggest
that Heliconius may acquire trap-line information by following experienced
individuals. Indeed, Heliconius often aggregate in social roosts, which
could act as ‘information centres’, and present conspecific following
behaviour, enhancing opportunities for social learning. Here, we provide a
direct test of social learning ability in Heliconius using an associative
learning task in which naïve individuals completed a colour preference
test in the presence of demonstrators trained to feed randomly or with a
strong colour preference. We found no evidence that Heliconius erato,
which roost socially, used social information in this task. Combined with
existing field studies our results add to data which contradict the
hypothesised role of social learning in Heliconius foraging behaviour.