Finches on two closely situated islands look different; on one island, they have brown tail feathers, and

Question:

Finches on two closely situated islands look different; on one island, they have brown tail feathers, and on the other island, they have black tail feathers. Can you conclude that these are two different species? How could you determine whether they are in fact distinct species?

Fantastic news! We've Found the answer you've been seeking!