Spring voices in Korean rice fields: The effect of abiotic variables and syntopic calls on the calling activity of the treefrog dryophytes suweonensis

The calling activity of anurans is influenced by environmental va ria bles a nd calls produced by syntopic amphibians, among other varia bles. Some varia bles have a strong influence, such as temperature and predation dilution, while others may have a periodical influence such as the moon cycle. Here, we hypothesised that the calling activity of the Suweon treefrog, Dryophytes suweonensis, is restricted by specific environmental variables but reinforced by the calling activity of specific syntopic anurans. Within the criteria set by the experimental design, D. suweonensis calling activity was significantly influenced by moon phase, tempera ture, da te, time to sunset and the calling activity of Pelophylax nigromaculatus and D. japonicus. These variables are expected to be related to chorus size, preda tion, breeding phenology and competition, suggesting a broad plasticity in the calling activity of the species.