Sensor selection in wireless sensor networks (WSN) is considered for target tracking. A decentralised estimation scenario is considered based on the extended information filter. A cost function using the geometrical dilution of precision (GDOP) measure is derived for active sensor selection. Accordingly, a new adaptive sensor selection (ASS) algorithm is proposed in which the number of active sensors is adaptively determined based on the absolute local innovations vector. Simulation results show that the tracking accuracy of the ASS is comparable to that of the other algorithms, but with less energy consumption.