An investigation of toe-tapping behaviour in anurans by analysis of online video resources

Toe-tapping is a widespread anuran behaviour commonly associated with feeding where the anurans move the middle toes of their hind legs up and down. Previous studies have interpreted it as a pedal lure, a prey localization method and a stimulus used to transfix prey. A database of online videos was constructed in order to study this behaviour across species, with a particular focus on arrow poison frogs (Dendrobatidae); tapping occurrence, prey characteristics and environmental factors were recorded. The data collected include 19 species that have, as of yet, not been recorded to tap, 16 of which exhibit feeding-related tapping, while in the three other species, tapping seemed to be related to courtship. Across dendrobatid species, a significant correlation was found between prey activity and the occurrence of tapping, which supports a prey localization hypothesis. The database proved to be a valid method of research as it provided a sample size large enough for detailed data analysis across the Dendrobatidae. The utility of the data was partially limited by the available number of observations per species and the inconsistency in video quality, however.