Birds exploit herbivore‐induced plant volatiles to locate herbivorous prey

Abstract

Arthropod herbivory induces plant volatiles that can be used by natural enemies of the herbivores to find their prey. This has been studied mainly for arthropods that prey upon or parasitise herbivorous arthropods but rarely for insectivorous birds, one of the main groups of predators of herbivorous insects such as lepidopteran larvae. Here, we show that great tits (Parus major) discriminate between caterpillar-infested and uninfested trees. Birds were attracted to infested trees, even when they could not see the larvae or their feeding damage. We furthermore show that infested and uninfested trees differ in volatile emissions and visual characteristics. Finally, we show, for the first time, that birds smell which tree is infested with their prey based on differences in volatile profiles emitted by infested and uninfested trees. Volatiles emitted by plants in response to herbivory by lepidopteran larvae thus not only attract predatory insects but also vertebrate predators.

Toward a List of Molecules as Potential Biosignature Gases for the Search for Life on Exoplanets and Applications to Terrestrial Biochemistry

“…Many volatile molecules produced as carriers of such signals are unique and originated from coevolution among species; hence it is impossible to predict which specific volatile molecule will be the carrier of which behavioral signal (e.g., Tirindelli et al, 2009;Deisig et al, 2014;Steiger and Stökl, 2014). An illustration of such a multispecies, intricate, and complex volatile chemical signaling network was discovered recently between apple trees, great tits (Parus major), and caterpillars of Operopthera brumata (Amo et al, 2013). Great tits respond to specific volatile molecules (dodecanal and alpha-farnesene) emitted by apple trees infested by Operopthera brumata (Amo et al, 2013).…”

“…An illustration of such a multispecies, intricate, and complex volatile chemical signaling network was discovered recently between apple trees, great tits (Parus major), and caterpillars of Operopthera brumata (Amo et al, 2013). Great tits respond to specific volatile molecules (dodecanal and alpha-farnesene) emitted by apple trees infested by Operopthera brumata (Amo et al, 2013). Attracted to the trees, the great tits eat the caterpillars.…”

“…Attracted to the trees, the great tits eat the caterpillars. The identity of volatile chemicals produced by caterpillar-infested trees and those that are free of them is very different and specifically tailored to Parus major olfactory receptors (Amo et al, 2013).…”

Evidence that the house finch (Carpodacus mexicanus) uses scent to avoid omnivore mammals

“…Kiwis, Wenzel 1968Wenzel , 1971Cathartes vultures, Gomez et al 1994;Graves 1992;Stager 1964), and it persists in several modern lineages (e.g. zebra finches, Kelly and Marples 2004;chickens Marples and Roper 1996; great tits Amo et al 2013b). Our results point out the need to conduct further experiments with natural fruits to examine whether olfaction plays a role in fruit ripening detection.…”

“…The importance of olfaction has been demonstrated amongst others in different species of Procelariiformes (e.g. Nevitt 2011, Bonadonnna andNevitt 2004), Galliformes (Hirao et al 2009), Spheniformes (Amo et al 2013a) and Passeriformes (Whittaker et al 2011, Amo et al 2013b). …”