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

Abstract

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.

Tap Dancing Frogs: Posterior Toe Tapping and Feeding inDendrobates tinctorius

“…We regularly observe Dyeing poison frogs ( Dendrobates tinctorius ) in our lab tapping their posterior toes (Movie S1 & S2). Toe tapping has been documented in various species of poison frog (family Dendrobatidae) [2], likely with some bias toward increased observations in this group resulting from the fact that these brightly colored, diurnal frogs are popular pets [1]. Poison frogs have dietary specializations for small prey items [12], and in the wild D. tinctorius feed on a variety of arthropod prey [13].…”

“…Under this umbrella, a related set of similar-looking toe movements have been broadly discussed in the context of visual and vibrational communication. Toe tapping has been suggested to function in prey capture (Claessens et al, 2020; Hagman & Shine, 2008; McFadden, Harlow, Kozlowski, & Purcell, 2010; Sloggett & Zeilstra, 2008), mate attraction and courtship (Landestoy & Ortíz, 2015; Starnberger, Maier, Hödl, & Preininger, 2018), aggression (Bee, Reichert, & Tumulty, 2016; Furtado, Márquez, & Hartz, 2017), and has also been suggested to be a ‘displacement behavior’ with no functional relevance (Furtado et al, 2017; Furtado & Nomura, 2014).…”

“…We regularly observe Dyeing poison frogs ( Dendrobates tinctorius ) in our lab tapping their posterior toes (Movie S1 & S2). Toe tapping has been documented in various species of poison frog (family Dendrobatidae), with some bias toward observations in this group likely resulting from the fact that these brightly colored, diurnal frogs are popular as pets and in zoos and aquaria (Claessens et al, 2020). Two recent studies demonstrated increased toe tapping associated with feeding in poison frog species closely related to D. tinctorius .…”

“…Variably referred to as toe tapping, twitching, wiggling, and trembling, this curious behavior is the subject of YouTube videos, TikToks, and Twitter threads. Indeed, a recent publication took advantage of online video sharing platforms to compile a toe tapping dataset of 222 videos of 389 individuals representing 63 frog species (Claessens, Ganchev, Kukk, Schutte, & Sloggett, 2020). Yet despite being readily observed and widely documented, the functional role of toe tapping remains poorly understood.…”

“…The toe tapping of various species of amphibians is an intriguing behavior that has attracted attention from researchers and pet owners. Variably referred to as toe tapping, twitching, wiggling, and trembling, this curious behavior is the subject of YouTube videos, TikToks, and Twitter threads [1]. Yet despite being readily observed and widely documented, the functional role of toe tapping remains poorly understood.…”