Temporal calling patterns of seven anuran species in southern Ontario

Globally, anurans have experienced significant declines and reliable monitoring protocols are required to track population trends. This thesis compares the effectiveness of manual call surveys (MCS) and automated recording systems (ARS) and describes the calling profiles of seven anuran species in southern Ontario. Using detailed audio recordings, we identify the seasonal and hourly calling patterns of seven anuran species at Warwick and Silver Creek Conservation Areas in the Credit River watershed. We employ descriptive and graphical methods to establish calling profiles. Given the low detection rate of American toads, grey treefrogs and northern leopard frogs, a survey protocol comprised of 9 weekly site visits are recommended in May and June. The optimal time of day for detecting the greatest abundance and species richness is 23h30 whereas optimal survey duration varies with hour and season given the target species. Climatic variables may induce or inhibit call activity and until the extent of these variables can be established, protocol guidelines should implement longer and more frequent site visits. The urgency of this revision is exacerbated for commercial surveys used to make contentious land management decisions.