title: Vocalizations in juvenile anurans: common spadefoot toads (Pelobates fuscus) regularly emit calls before sexual maturity.
abstract: Acoustic communication is prominent in adult anuran amphibians, in reproductive, territorial and defensive contexts. In contrast, reports on vocalizations of juvenile anurans are rare and anecdotal, and their function unstudied. We here provide conclusive evidence for vocalizations in juvenile spadefoot toads (Pelobates fuscus) in very early terrestrial stages. While the aquatic tadpoles did not emit sounds, first vocalizations of metamorphs were heard as early as in stages 42-43, and calls were regularly emitted from stage 44 on, often from specimens still bearing extensive tail stubs. Three main types of calls could be distinguished, of which one consists of a series of short notes, one of a typically single longer and pulsed note, and one of a single tonal note. In experimental setups, the number of calls per froglet increased with density of individuals and after feeding, while on the contrary calls were not elicited by playback. The function of these juvenile calls remains unclarified, but they might reflect a general arousal in the context of feeding. Further evidence is necessary to test whether such feeding calls could confer a signal to conspecifics and thus might represent intraspecific acoustic communication in these immature terrestrial amphibians.
authors: Zoological Institute, Technical University of Braunschweig, Mendelssohnstr. 4, 38106, Braunschweig, Germany.|AG Zoologischer Garten Köln, Riehler Straße 173, 50735, Cologne, Germany.|Cologne Biocenter, University of Cologne, Zülpicher Strasse 47b, 50674, Cologne, Germany.
authors: Leonie
authors: L
authors: Ten Hagen
authors: Zoological Institute, Technical University of Braunschweig, Mendelssohnstr. 4, 38106, Braunschweig, Germany.
authors: Ariel
authors: A
authors: Rodríguez
authors: NABU-Naturschutzstation Münsterland e.V, Westfalenstraße 490, 48165, Münster, Germany.
authors: Norbert
authors: N
authors: Menke
authors: NABU-Naturschutzstation Münsterland e.V, Westfalenstraße 490, 48165, Münster, Germany.
authors: Christian
authors: C
authors: Göcking
authors: , Winds-Wieske 4, 59320, Ennigerloh, Germany.
authors: Michael
authors: M
authors: Bisping
authors: Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstrasse 43, 10115, Berlin, Germany.
authors: Karl-Heinz
authors: KH
authors: Frommolt
authors: AG Zoologischer Garten Köln, Riehler Straße 173, 50735, Cologne, Germany.|Cologne Biocenter, University of Cologne, Zülpicher Strasse 47b, 50674, Cologne, Germany.
authors: Thomas
authors: T
authors: Ziegler
authors: Cologne Biocenter, University of Cologne, Zülpicher Strasse 47b, 50674, Cologne, Germany.
authors: Michael
authors: M
authors: Bonkowski
authors: Zoological Institute, Technical University of Braunschweig, Mendelssohnstr. 4, 38106, Braunschweig, Germany. m.vences@tu-braunschweig.de.
authors: Miguel
authors: http://orcid.org/0000-0003-0747-0817
authors: M
authors: Vences
mesh_terms: D000818:Animals; D001001:Anura / Q000254:growth & development / Q000502:physiology*; D005247:Feeding Behavior / Q000502:physiology; D012741:Sexual Maturation / Q000502:physiology; D014828:Vocalization, Animal / Q000502:physiology*
keywords: Acoustic communication; Amphibia, Anura, Pelobatidae; Juvenile calls; Metamorphosis