Underground nesting is a common behavior among burrowing birds, who create horizontal tunnels in vertical dirt cliffs or dig holes directly into the ground. Different species of burrowing birds use different methods to create their nests. Some, like sand martins, excavate their own tunnels and chambers, while others take over rodent and mammal holes, such as rabbit burrows, like the common kingfisher. For some species, like the European bee-eater, nesting in colonies is the preferred option, with multiple tunnels leading to a central chamber where the eggs are kept. Regardless of their chosen method, these birds all share the same goal of providing a safe underground shelter for their young.
Different bird species have unique ways of building nests to protect their eggs. For instance, some species create mound nests by burying the eggs under soil, mud, or stones. Megapode birds from Asia and Australia construct massive piles of decaying organic matter to incubate their eggs. Flamingoes, on the other hand, shape cone-shaped mud mounds to shield their eggs from heat and varying water levels. Meanwhile, the horned coot in South America creates a structure using stones in shallow water and places an aquatic vegetation platform on top. These different nest-building techniques are crucial in ensuring the survival of bird species and preserving their populations.
Cavity nests refer to chambers found in either live or dead wood, as well as insect nests. However, not many species have the ability to create their own cavities, with woodpeckers and trogons being among the few exceptions. The majority of cavity dwelling creatures, such as owls, kingfishers, parrots, and hornbills, utilize natural crevices or ones that have already been excavated by other species. These animals often line the interior of their holes with soft materials like feathers. To attract cavity-nesting animals to your area, you can easily do so by placing nest boxes around your property.
Craftsmen create hanging sacks by weaving together various plant fibers and grasses. They then fasten these sacks to tree branches.