Gould found more species than Darwin had expected, and concluded that 25 of the 26 land birds were new and distinct forms, found nowhere else in the world but closely allied to those found on the South American continent.
Gould encontrou máis especies que as que Darwin esperaba, e chegou á conclusión de que 25 das 26 aves de terra eran formas novas e distintas, que non se atopaban en ningunha outra parte do mundo pero estaban estreitamente relacionadas coas encontradas no continente suramericano.