Under these drastically changing conditions, the struggle to survive favored the larger birds with deep, strong beaks for opening the hard seeds. Smaller finches with less-powerful beaks perished.

The beak may need regular and careful trimming by a vet and rasping with an emery board may also help. In some cases the abnormal growth is due to an infection with a mite called Cnemidocoptes pilae.

Beak problems can be a huge sign of underlying health issues that need immediate attention. So, if you notice abnormal growth, discoloration, or any other sign of distress, it’s super important ...

For example, the cactus finch has a long beak that reaches into blossoms, the ground finch has a short beak adapted for eating seeds buried under the soil, and the tree finch has a parrot-shaped ...