Abstract Existing target tracking algorithms require the tracker to have access to information-rich sensors, and may have difficulty recovering when the target is out of the tracker's sensing range. In this paper, we present a target tracking algorithm that combines an extremely simple mobile robot with a networked collection of wireless sensor nodes, each of which is equipped with an unreliable, limited-range boolean sensor for detecting the target. The tracker maintains close proximity to the target using only information sensed by the network, and can effectively recover from temporarily losing track of the target. Our approach combines a protocol for the sensor network that conserves energy by dynamically adjusting the time-to-live for packets it transmits with a reactive strategy for the tracker based on its information state. We present an implementation along with experimental results. Our experimental results show that our system achieves both good tracking precision and low energy consumption.