In this paper, we introduce a loss reduction scheme, Adaptive Burst cloning, as a technique to ensure service-guarantees in optical burst-switched (OBS) networks. The basic idea is to replicate a burst and send its duplicate copies through the network in parallel. Incase the original burst gets lost, the cloned burst may still be able to reach the destination. Unlike the existing burst cloning techniques, Adaptive Burst Cloning selects the clone node and the number of cloned bursts dynamically. Due to dynamic selection of the clone node and the number of cloned bursts, utilization of network resources is considerably low, and as a consequence, burst loss due to resource contention is significantly reduced. We develop a network level simulation model to investigate the proposed Adaptive Burst Cloning loss recovery mechanism and compare its performance with the existing static burst cloning technique. Our results show that the proposed mechanism significantly reduces the packet loss in an optical burst-switched network with relatively lesser resource utilization.