Wildlife Habitat Snags
This tree has been preserved for cavity-nesting birds and other wildlife (just like with many others). Dead, dying, and decayed trees provide many benefits to wildlife living within and passing through our urban forests. Perhaps most importantly, cavity-nesting birds (barn owls, kestrels, nuthatches, and more) need these types of trees to raise their young. People who manage trees are sometimes interested in preserving dead and dying trees to enjoy more wildlife in these spaces.
Tree owners and managers make difficult decisions about how to care for their trees and when to remove them. Sometimes these decisions are easy:
- Young, healthy, vigorously growing trees rarely need to be removed.
- Large, dead trees overhanging areas where people spend a lot of time probably should be removed.
When considering retaining a tree for wildlife value, it is best to first obtain an assessment from an arborist. Some features that are valuable to wildlife may increase the likelihood of a branch or tree breaking or toppling. As such, not every tree is appropriate to preserve for wildlife value. Trees retained for wildlife habitat in areas with people or high-value property should have a plan for continued monitoring and eventual removal.
The International Society of Arboriculture (ISA) provides resources to arborists about working with wildlife.
ISA's Tree Risk Assessment Best Management Practices (2025) say:
Dead trees, as well as live trees with dead branches, decay, or cavities, provide habitat for many organisms. Dead trees or dead branches retained for wildlife habitat can be assessed for risk like any other tree. Selection of suitable wildlife habitat trees must consider the risk, as well as its value for wildlife. Removing a large portion of the trunk and branches may be appropriate to create or maintain wildlife habitat while managing risk.
Ultimately, it is up to the owner of the tree to ask for assessments and make all tree management decisions. The owner or manager of this tree has determined that the benefits of wildlife habitat outweigh the risk this tree poses.
Tree Risk Assessment Qualified arborists can help risk managers and owners decide how to balance risk posed by dead and dying trees and branches with the potential for wildlife habitat. Wildlife Trained Arborists have even more training about wildlife, habitat, Tree Care for Bird's Wildlife Best Management Practices, and laws to help make these decisions.
Signs can be purchased through the Britton Fund.
Art by Melissa Orozco Art.
Disclaimer: The Tree Care for Birds Committee and the Western Chapter of the International Society of Arboriculture make these signs available as a general educational resource for arborists and tree managers. They do not provide professional assessments of individual trees, and have no knowledge of, involvement in, or responsibility for decisions regarding which trees are preserved as wildlife habitat or removed due to risk considerations. All users should exercise independent professional judgment and, where appropriate, seek additional expert consultation.
This sign is 9 inches wide, 11 inches tall, and 3 mm thick. It has a plastic core between two thin layers of aluminum and a vinyl print protected with UV laminate for outdoor use.