Avian species were historically thought to have a very limited sense of smell. However, recent studies suggest that odor plays an important role in many areas of avian life, including foraging and navigation. It has been shown that insectivorous birds can interact in a tritrophic fashion with plants and their herbivores by cuing in on herbivore-induced plant volatiles (HIPVs), important signaling compounds released by plants in response to herbivorous damage. This phenomenon has been observed in a number of plant species, including complex HIPV blends in corn (Zea mays). However, in other species, simpler single-compound HIPVs can act as phytohormones, causing the release of additional HIPVs, and have also been shown to be attractive to birds. Here we test if 2 single-compound general HIPVs, methyl jasmonate and methyl salicylate, attract avian predators to insect prey on corn plants using clay caterpillar models. We observed appreciable levels of bird attacks on our models across 10 experimental sites. However, we did not observe any difference between HIPV and control treatments. Interestingly, we did find that several weather variables, including wind speed and temperature, were significant or near significant predictors of avian predation activity, respectively. Together with previous studies, our results add to a nuanced picture of how birds may be using HIPVs to locate insect prey. Additionally, the potential for birds to act as a natural form of biocontrol in agricultural settings may be affected by physical location and local climate.

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