He discovered that each finch in each diffrent island had a slightly diffrent beak adapted to its particular environment. For example, a fruit eater had a stout beak to pick berries off branches and a seed eater had a short, powerful bill for crushing seeds, etc. This contributed to his theory of evolution.
Darwin was interested in the finches! The finches weren't interested in him!
On each island of the Galapagos Islands
All known species of Darwin's Finches are found on the Galápagos islands. With the exception of one, the Cocos Finch, which is found on the Cocos Island. Darwin's finches are not actually true finches. Darwin knew they weren't finches, but an ornithologist called Percy Lowe, later in 1936 incorrectly called them "Darwin's Finches" in a book, a term which unfortunately stuck.
Galapagos finches
Charles Darwin discover the finches in Galapagos in 1831. He noticed that the finches beaks were different compared to the finch's in Ecuador.
Darwin was puzzled about the many adaptations of the finches on the Galapagos Islands
Finches and turtles
Finches...he based his theory on the shape of their beaks
That they were evoled from on specie of finches.
Darwin was puzzled about the many adaptations of the finches on the Galapagos Islands
Geographic isolation of a common ancestral species of finches
It is thought that the finches have a common ancestor. Separated on different islands, each island eventually produced different finches.