Is “Shou Sugi Ban” Suitable for Nest Boxes?

By Robyn Bailey, NestWatch Project Leader

When David Alva from California wrote to ask us if burning the outside of a nest box using a technique called “shou sugi ban” would discourage birds from using it, we didn’t have enough experience with the process to answer with certainty. However, we do know that birds nest in holes in fire-killed trees often, so the burned wood shouldn’t be a deterrent to birds. Therefore, we encouraged David to report back if he decided to try it.

What is shou sugi ban?

Shou sugi ban (also called yakisugi) is a centuries-old Japanese wood-finishing technique that involves charring the surface of wood to enhance its durability and aesthetic appeal. The process entails burning the exterior surface of the wood in a controlled way, creating a distinct blackened exterior while preserving the natural texture and grain of the wood underneath. The charring process makes the wood more resistant to rot, insects, and weather, enhancing its lifespan without the need for chemical treatments. Speaking of chemical treatments, it’s important to use untreated wood for a shou sugi ban project, since burning pressure-treated wood can be very harmful to human health (note especially the risk of inhaling hazardous dust like arsenic). Shou sugi ban is traditionally practiced on cedar boards, which is what David used. David told us that, “The reason I burned it was to create a weather resistant finish without the use of paints or solvents. I was concerned that these would give off vapors which might dissuade an owl from taking up residency.  I learned about burning wood from the home improvement shows.”

The verdict?

A few months later, David reported back that burning the wood did not discourage the Western Screech-Owl he was targeting from roosting in the box. He snapped a photo from a cautious distance as evidence (being careful to avoid spooking the sleepy owl). Although the owls were likely already nesting when David installed this box, it’s a good sign that one is checking out the new home. He’s hopeful that they will continue to nest in his yard as they have done in years past. We thank David for sharing this nest box project with us and reporting back on the result; we’ll update this post if we learn more in the future. In the meantime, we invite other NestWatchers to share their experiences with shou sugi ban in the comments to help our community continue learning!

Banner Photo by Qingyue Li, under cc-by-2.0 (modified).