Tree hollows are natural cavities found in the trunks or branches of trees. They are formed over time through processes like decay, insect activity, or damage from storms. These hollows provide essential habitats for various wildlife, including birds, bats, and small mammals. Many species, such as the Eastern Bluebird and Sugar Glider, rely on tree hollows for nesting and shelter. The presence of hollows can indicate a healthy forest ecosystem, as they contribute to biodiversity and offer protection for many organisms.