Malcolm F. Rosenthal https://orcid.org/0000-0003-1291-1728
Rowan McGinley https://orcid.org/0000-0003-3593-4754
Date of this Version
Published as: Rosenthal M.F., Hebets E.A., McGinley R., et al. Exploring a novel substrate-borne vibratory signal in the wolf spider Schizocosa floridana. Ethology 127 (2021), pp 135–144. doi:10.1111/eth.13114
Animals communicate using a diversity of signals produced by a wide array of physical structures. Determining how a signal is produced provides key insights into signal evolution. Here, we examine a complex vibratory mating display produced by male Schizocosa floridana wolf spiders. This display contains three discrete substrate-borne acoustic components (known as “thumps”, “taps”, and “chirps”), each of which is anecdotally associated with the movement of a different body part (the pedipalps, legs, and abdomen respectively). In order to determine the method of production, we employ a combination of high-speed video/audio recordings and SEM imaging of possible sound-producing structures. Previous work has suggested that the “chirp” component is tonal, a signal trait that would be potentially unique in the genus. We measured signal tonality for all courtship components, as well as for courtship components from sixteen other Schizocosa wolf spiders. Our results suggest that S. floridana produces courtship song using a combination of shared (palpal stridulation and foreleg percussion) and novel (abdominal movement) sound production mechanisms. Of particular interest, the “chirp”, which is produced using a novel abdominal production mechanism, is the only known tonal signal with acoustic properties that are unique within the genus. We argue that the potential evolution of a novel sound production mechanism has opened up a new axis of signaling trait space in this species, with important implications for how this signal is likely to function and evolve.
Hebets ETHOLOGY 2021 Exploring a novel substrate VIDEO 2.mov (2677 kB)
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