Do crowdsourced observations of katydids reflect the relative risks of mate finding strategies?

Locating potential mates is critical to the survival of individuals and species. Orthopterans, particularly tettigoniids, have diverse mate advertisement and searching strategies involving unidirectional acoustic calling, where one sex calls and the other one searches; or duetting, where one sex calls, the other replies, and either or both search. The mate finding strategy of a species can affect the relative risk of predation for callers and searchers, with females of non-duetting species sometimes incurring greater risk than females of duetting species. Studies of these risks are often limited to a small number of tettigoniid species or examine the prey of a single type of predator, so a more general description of the relative risks of roles in different mate finding strategies has remained elusive. Here, I leverage observations from the community science network iNaturalist to examine whether searching female tettigoniids are at a greater risk of being "captured" by predators—in this case, human iNaturalist users. Using a global dataset of more than 100 species, I compare the proportion of females observed in taxa where the dominant mate searching strategy is duetting versus unidirectional calling. I find that significantly fewer females are observed in duetting taxa, consistent with the hypothesis that duetting shifts the predation-based risks of mate searching towards males.