Every kind of bird has its own capacity to colonize other areas. Some are very poor colonizers, some are fantastically good colonizers. For instance, when you take New Guinea. New Guinea has something like 64 families of birds, but then when you got into Polynesia, which was… was colonized from New Guinea, only 16 of the 64 families have contributed species and genera to the Polynesian fauna, and the same you find in other areas of the world. In the Caribbean, for instance, of the mainland families and genera and species, a certain percentage gets over to the Caribbean, to the… Caribbean islands, while others are unable to do so. And Jared Diamond found, for New Guinea, that there are about 30% of the New Guinea species, and I'm talking now only about lowland species, that do not settle on any island around New Guinea that is more than one mile away from the mainland coast. In other words, dispersal facility is a very important characteristic of bird species and bird genera.