Clubbing is an enlargement of the ends of the fingers and a downward sloping of the nails. Although it's not caused by chronic obstructive pulmonary disease (COPD), it can be a sign of coexisting lung cancer or other lung disorders in patients with COPD. Clubbing is sometimes called digital clubbing. It can affect the fingers and/or toes.
Relatives. Darwin's finches can be divided into groups based on beak type. There are three species of tree finch: the small tree finch, medium tree finch, and large tree finch. Tree finches have grasping beaks.
Medium ground-finch biology. The highly specialised beaks of Darwinâs finches enable each species to occupy a different ecological niche based on different food types. The ground finches (Geospiza sp.) feed mainly on the ground and are generally granivorous, but also feed on arthropods and the fruit of Opuntia cacti. Having an intermediate sized beak, the medium ground finch is described as a generalist, able to exploit a broader range of seed sizes than the other ground finches.