Kingfishers in new guinea are separated into distinct subspecies. which two subspecies would you expect to be most genetically different from one another?

Considering we are talking about New Guinea we might expect that the subspecies that would be most genetically different from one another to be those that have specialized in different ways of acquiring food. The reason for this is the fact that different ways of acquiring food often is accompanied by a different set of skills one needs in order to achieve that goal