Which piciform birds excavate their own nesting cavities?

Most members of the order Piciformes are capable of excavating their own nesting cavities, a behavior that is considered a major factor in their evolutionary success.12

The following groups within the order are known to excavate their own nests:

• Woodpeckers: These birds are the most specialized at this task, often using their sturdy bills to chisel cavities into trees, fence poles, or cacti. Some species, such as the ground woodpecker and the Andean flicker, excavate their nests in the ground or in banks.2
• Barbets: These birds typically excavate cavities in trees, though some species may burrow into the ground or into termite nests.2
• Jacamars: These birds excavate nesting tunnels in banks or steep hills.2
• Puffbirds: These birds excavate their nests in the ground or in termite nests located on the ground or in trees.2
• Piculets: These birds construct their nests in small trees, stubs, or fence posts.2

In contrast, honey guides are generally brood parasites that lay their eggs in the nests of other species, and toucans typically utilize natural cavities or old nests abandoned by other birds.2