This paper presents the mechatronic design of a robotic arm that is mounted on a ground rover and used to deploy and recover small-scale unmanned aerial vehicles. The arm and rover are part of a network of collaborative robotic agents aiming to enhance current rescue operations by supporting human operators without burdening them with servicing tasks. The robust autonomy of the system, guaranteed in part through the addition of this robotic arm, is a main contributing factor. Design requirements are derived from the context of the rescue mission and a kinematic analysis is provided that leads to a customized design, including variable stiffness joints for compliant interaction with the environment. Experiments demonstrate the system's ability to perform the required Cartesian trajectory control and manipulation tasks, and to achieve a desired variable end-effector compliance.