In this study, a receiver initiated cooperative medium access control (RIC-MAC) protocol is proposed for cooperative communications to reduce the energy consumption of wireless sensor networks (WSNs). Considering a real WSN plat-form, the simulation results show that using the proposed RIC-MAC protocol in cooperative communications provides latency and energy gains as compared to multi-hop communications. However, the energy gain is shown to be reduced when the network traffic load increases. Finally, considering the impact of traffic load on energy consumption and latency, RIC-MAC is illustrated to be robust to traffic load variations in terms of latency.