Mobile Ad Hoc Networks (MANETs) offer quick and easy network deployment in situations where it is not possible otherwise and they can be used to provide mobile users with a temporary infrastructure to use services in the absence of fixed infrastructure. Nodes in MANETs are free to move and organize themselves in an arbitrary fashion. The challenging task in such dynamic environments is how to improve the service availability. Replicating a service at some nodes distributed across the network is an effective strategy. However, service replication can considerably impact the system energy consumption. Since mobile devices have limited battery resources, a dynamic and efficient service replication is necessary to support such environments. In this paper, we propose a distributed service replication scheme for achieving high service availability with reasonable energy consumption for MANETs. The proposed method called HDAR (Highly Distributed Adaptive Service Replication) divides the whole network into disjoint zones of at most 2-hops in diameter and builds a dynamic replication mechanism which selects new replica zones depending on their service demand and the tradeoff between the communication and replication energy consumption costs. Through simulations, we confirmed that our approach can achieve higher service availability with reasonable energy consumption than existing methods.