Calling phenology of anurans in a tropical rainforest in South Mexico: testing predictive models

Abstract

ABSTRACT Anuran calling activity has been widely associated with abiotic factors, such as temperature, rain and photoperiod. In this sense, mathematical modelling could help us to decipher the mechanisms that underlie these phenomena in order to be able to predict possible scenarios. Here, we propose 15 models that incorporate some environmental variables with biologic relevance: photoperiod, accumulated rain, dry/wet season, and annual mean temperature. The calling activity patterns were obtained with an automated recording system (ARS) for 7 months in Nahá, Chiapas, Mexico, where nine species were recorded. Those models were compared through the Akaike information criterion corrected for small samples (AICC ) to find the one that best fits. Our results point to a sinusoidal model containing photoperiod, dry-wet season and accumulated rain as the best model. Photoperiod resulted as a critical variable driving phenological calling activity patterns since whenever it was incorporated in a model, its values were reduced. It is interesting because the photoperiod, through photoreception, allows anurans to synchronise their physiology and behaviour throughout the year, being able to control the growth, development and maintenance of organisms by starting the reproduction phases in optimal seasons for their development. However, it is also important to highlight that phenological structure of the anuran calls in Nahá, México is better explained by a combination of mechanisms, which includes photoperiod, rainfall and seasonality, but not temperature.