Current methods for the assessment of amphibian population abundance and density are either invasive and time-consuming, or qualitative and subject to unquantifiable observer biases. 2. We propose an acoustic spatially explicit capture-recapture (SECR) method to estimate population abundance and density for calling frog species, which avoids the problems above. It produces an estimate of call density which can be converted to frog density by using call rate data. Time-of-arrival and signal strength data are used...