Living in the 80s - seasonality and phenology of frog calling activity at Darkes Forest from 1987-1989

Abstract

We recorded the calling activity of frogs at a permanent pond 80 km south of Sydney between 1987 and 1989, documenting the calling seasons of five species and relating calling activity (within calling seasons) to temperature, humidity, barometric pressure and rainfall. Three species commenced calling in August/September with Litoria peronli and Uperokia laevigata calling consistently throughout the summer months and Umnodynastes dumerilil calling more sporadically. Limnodynastes peronii appeared capable of calling at any time of the year, but did not call continuously. Litoria verreauxii called very consistently from January to September. Random effects models indicated that the probability of males calling increases with increasing temperatures in Limnodynastes peronli, Litoria peronii and Uperoleia laevigata. Increasing barometric pressure was positively associated with calling in Umnodynastes peronii. Calling was not related to either rainfall or humidity for any species. The calling seasons were similar to expectations based on published information. The lack of relationships between calling and rainfall and humidity may be related to the presence of permanent water and or the regular rainfall experienced throughout the study period. Historical data from this study may provide a baseline for future studies to assess changes in calling phenology linked to climate change.