Trees, snags and logs are primary substrates providing nesting sites, shelter, and food for the majority of woodpeckers.
Woodpeckers have evolved the anatomy and skills to excavate deep nesting chambers and foraging holes in trees. Studies of rare or endangered woodpeckers often indicate that these species need a substantial number of mature, “overmature,” or dead and dying trees upon which to forage or excavate cavities.
Cavities are the most obvious signs that woodpeckers leave to reveal their presence. Some are used as nesting sites, others as roosts while a few can be used for both.
Certain woodpeckers within the nest-web can be regarded as keystone species, such as the black woodpecker (Dryocopus martius) that provides the largest cavities in Europe.
Woodpecker
