Aliphatic esters: The missing link in fruit-frugivore olfactory communication?
Organismic Interactions, Chemical Ecology and Microbiomes of Plant Systems
Final Report Abstract
Fleshy fruits have evolved to attract animal seed dispersers to consume them and disperse their seeds. Fruit scent is increasingly recognized as an evolved communication system between plants and animals that tend to rely on their sense of smell. Previous studies have assumed that the information conveyed in fruit scent is simple and is limited to whether a fruit is ripe or not. This small project suggested that this is not the case, and that fruits may convey information on fruit quality as well. Particularly, it tested whether ethanol levels and aliphatic esters, which are synthesized from products of fruit maturation, can inform animals of fruit quality, and whether animals are capable of detecting sugar levels based on scent alone. The project took place in South Africa and Madagascar. It found that African elephants are capable of detecting sugar levels in fruits based on scent alone, even if these differences are miniscule. This joined other studies in demonstrating the excellent sense of smell possessed by elephants. The results were also highlighted by the German Radio Deutschlandfunk (audio): “Exzellenter Geruchsinn: die Supernase der Elefanten”. In Madagascar, work on wild figs showed that indeed some components of fruit scent are systematically associated with sugar levels and hence fig quality, thus offering local seed dispersers a key to assessing fruit quality before ingesting them. Taken together, the results of the project demonstrate, for the first time, that fruit scent is a much more nuanced communication system than previously thought, opening the doors to future research on its evolution and ecological functions.
Publications
- (2020). Sweet tooth: Elephants detect fruit sugar levels based on scent alone. Ecology and Evolution, 10, 11399–11407
Nevo O., Schmitt MH, Ayasse M, & Valenta K.
(See online at https://doi.org/10.1002/ece3.6777)
