Migratory species

A species or lower taxon of wild animals of which the entire population or any geographically separate part of the population cyclically and predictably cross one or more national jurisdictional boundaries. (CMS, Art. 1). The word 'cyclically' relates to a cycle of any nature, such as astronomical (circadian, annual etc.), life or climatic, and of any frequency; (ii) The word 'predictably' implies that a phenomenon can be anticipated to recur in a given set of circumstances, though not necessarily regularly in time (CMS, Res. 11.33) (Source: CMS)