The data below shows the populations of Jamalihs Jays from the Tantropesioan Islands in the south Pacific. These Islands are all small and in close proximity to one another and the birds easily migrate from one Island to the other. Jamalihs Jays recognize each other by a distinct mating call the had often been compared to the call of the nesting redwood owl. Island 1: 60 Jays
Island 2: 72 Jays
Island 3: 69 Jays

Why have the Jamalihs Jays remained one species even though they are spread out between three islands?