Experienced, but not naïve, birds use herbivore-induced plant volatiles
to locate prey, learning one tree species at a time.
Abstract
In tritrophic interactions, birds are able to detect herbivore-induced
plant volatiles and use them as a signal of presence of arthropods on
plant. It remains unclear whether this ability is innate or learned and
how the birds react to novel odours. We studied whether and how naïve
and trained great tits (Parus major) discriminate between
herbivore-induced and noninduced saplings of potentially familiar and
novel plant species. Birds trained to discriminate between saplings of
either novel or familiar plant species preferred the induced saplings of
the plants species they were trained to. Naïve birds did not show any
preferences. Our results indicate that the attraction of great tits to
herbivore-induced trees is not innate. Yet, the skill can be acquired
through learning and novelty of the odour doesn’t seem to be important.
This implies that birds are learning whole bouquets of the
herbivore-induced volatile compounds, rather than specific compounds
individually.