Bat-moth-interactions are regularly portrayed as a textbook example of coevolution: the evolution of echolocation in bats caused the evolution of hearing and anti-bat behaviours in moths, causing the evolution of some only vaguely supported bat strategies to counter moth hearing. In this talk, I will discuss the sensori-motor strategies of moths to escape from bats, and question our own notion of sensory coevolution to moth hearing in bats. 

Moths seem to exhibit a two-staged evasive flight response to attacking bats. While the moths’ neuronal encoding of bat echolocation calls is rather well studied, we lack a similarly broad and comparative understanding of moths’ evasive flight response. Using a community of eared moths and echolocating bats, I will ask whether the simple ears of moths can correctly encode the predation threat of different bat predators. Neuronal audiograms, neuronal thresholds for bat calls collected in the lab and field, modelling of evasive flight, and preliminary systematic behavioural recordings suggest that moth hearing is well adapted to its sympatric predator community. 

From the bats’ perspective, I will focus on stealth echolocation, i.e., low-amplitude echolocation calls that are inaudible to eared prey. Stealth echolocation is to date the best-supported example of a coevolutionary response of bats to the defence strategies of eared moths. However, while the functional benefits of stealth echolocation are well supported, the history of its evolution is not. Considering phylogeny and other selection pressures on echolocation beyond prey hearing, I propose an alternative hypothesis for the evolution of low-amplitude echolocation. While low-amplitude echolocation appears ill suited for flying and hunting in open space, it is likely beneficial in cluttered space. Low-amplitude echolocation thus might have evolved as adaptation to dense habitats, secondarily allowing some pre-adapted bats to hunt for eared moths.

More about the speaker

Holger R. Goerlitz, Acoustic and Functional Ecology, Max Planck Institute for Ornithology Seewiesen, Germany

www.orn.mpg.de/AFEG

Participation

The seminar is open to all, free of charge and will take place in the AIAS conference room 203, Building 1632, Høegh-Guldbergs Gade 6B, 8000 Aarhus C. Coffee and tea will be served.

Organizer

Professor Peter Teglbjerg Madsen, Jens Christian Skou Fellow at AIAS, Dept. of Bioscience, Aarhus University, Denmark.