the Darwin or Galápagosfinken, a type-group of the buntings, occurs with 13 types exclusively on the Galápagos-Inseln. Usually, the Cocosinselfink Pinaroloxias, that is native on the 850 km of distant Cocos-Inseln, becomes as 14. Type added.
Darwinfinken and the theory of evolution Darwins The birds were revealed to 1835 by Charles Darwin and gave it crucial stimulation for the installation of its evolution-theory. Darwin found a bird-community of surprisingly similar forms, that taking advantage of all food-sources of its living space was capable. The similarity of the birds led to the justifiable assumption that all here living forms go back to a common ancestor-form, that at a former time, tertiary?) from the south or Central America-recess mainland from the remote Galápagos-Inseln reached. This ancestor-form came on an island-group almost uninhabited from birds and could multiply strongly here, since neither enemy nor competitors influenced the development.
Mutation, selection, type-formation Originally, the Darwinfinken lived exclusively from seeds. With increasing Individuenzahl, however, those animals were favored by the natural selection (selection), that differed through heritage-alterations (mutations) of the original-form and could open up so new life-bases for itself. So the original type changed and split into several development-lines, that it allowed to take advantage of the given possibilities of the habitat fully and to reduce the competition among each other so. Competition meant above all food-competition in this case so that the modifications of the original-form manifest themselves mainly in the different beak-forms of the again originated types. The beak offers an important systematic basis with it.
System The type of the reason-finches (Geospiza, 6 types) distinguishes itself through a thick beak, that even is suitable to cracking with the more highly developed types from hard seeds. Therefore they are called also Kernbeißerfinken while the schwachschnäbligeren reason-finches eat small and soft seeds. The cactus-finch (Geospiza scandens) looks also for nectar with its profoundly split tongue.
The tree-finches (type Camarhynchus, 3 types) can break off bark-pieces with its also powerful beak in order to catch them living insects under it.
The longer beak of the Stocherfinken (type Cactospiza, 2 types) allows poking around in the bark-splits after type of the woodpeckers. If the beak-length is not enough, they break off a short small rod or a cactus-thorn, hold the "tools" with the beak and poke the insect-larvae living under the bark with it out. Long one believed that the Stocherfinken are the single types among the birds, who use objects as tools. Meanwhile, this behavior is proved with further bird-types.
The short and bulky beak of the Pflanzenesser-Baumfinks (type Platyspiza, 1 types) reminds of a parrot-beak. Hereby, fruits can be squashed under high pressure.
The foliage-singer-finch (type Certhidea, 1 types) scans leaves and branches after insects, that aufpickt it with its slim beak.
Scientific name: