‘Cry For Help’: Differential Benefits Gained by Native and Invasive Species of Plants from Insectivorous Birds

Plants signal for help to birds when they are being eaten by insects, providing preliminary evidence for the existence of a beneficial mutualism between plants and birds (Mantyla et al. 2010). Plants release volatile organic compounds (VOC’s) when damaged by herbivorous insects that birds can smell, detecting the presence of insects on the plant that they can eat. This experimental study tested whether native species of plants are more adapted to signal for help from birds when being damaged by herbivorous insects than compared to exotic species of plants with similar morphology, in order to test whether or not this is a co-evolved trait. In order to test this, I set up on experiment where bags of ripped leaves were placed on plants to simulate the release of VOC’s. Fake clay caterpillars were placed on the plants in order to collect data on the number of pecks by birds that each plant receives. Using three pairs of native and invasive species of plants with similar morphology, I determined whether native species were better at signaling for help from birds than their non-native counterparts. The result of the experiment showed that some native plants were indeed better at signaling for help to birds, which was indicated by a greater number of bird visitations. The findings also confirmed that the presence of VOCs was responsible for reduction of insect plant damage. The experimental findings suggesting that chemical communication between birds and plants is a co-evolved relationship that has an important role in mediating interaction among trophic levels