Abstract - The objective of our project is to design a wireless sensor network that detects calls of the frog species - Nasikabatrachus sahyadrensis, more commonly known as the purple frog. One of the major challenges of the project is that the frog stays underground for most of the time, and surfaces for about two-three weeks in the monsoon period. Since constant human supervision is impractical, we propose an acoustic sensor network to overcome the problem. The system has a two-tier architecture, with a resource constrained level one nodes and a resource rich level two nodes. The level-one nodes are involved in the data collection and compression, while we implement the resource rich operations such as FFT in the level two nodes.