Migratory species are found all over the world - on land, in the water and in the skies. Traversing thousands of miles, these species rely on a diverse range of habitats for feeding, breeding and resting, and in turn, play an essential role in the maintenance of healthy and functional ecosystems. Often their migrations take them across national borders, and thus international cooperation is essential for their conservation and survival. The recognition of this need led to the negotiation of the Convention on the Conservation of Migratory Species of Wild Animals (CMS), which came into force in 1979. CMS is the global treaty that addresses the conservation and effective management of migratory species and their habitats. The Convention aims to conserve migratory species, particularly those listed in its two Appendices and those included in a range of CMS instruments, through international cooperation and coordinated conservation action.