To explain the existence of multiple handicap signals, multiple receiver hypothesis has been proposed. In an environment, rivals and mates potentially assess different signals, thus making more than one ornament maintain stable condition-dependent signals, reflecting different qualities or associated costs. These signals are maintained because they target different receivers and reflect different aspects of fitness. This is extended to explain increasing complexity of signals, where different receivers are receptive to different aspects of the same signal. In the case of the red-collared widowbird, the elongated tail addresses female choice, while the red carotenoid badge addresses aggressive male competition over territory.