In general, there are two fixing methods for wildlife nest boxes or log boxes;
- hanging with rope or wire
- drilling and / or screwing into the tree
Often a hanging system is chosen to avoid wounding the tree however we usually recommend against this. Use of wire or chain to hang a wildlife box will inevitably create a large horizontal wound where the wire cuts into the tree, insulating the wire with hose lasts only a few years, leaving the wire loose or sprung allows the box too much movement. Hanging from rope is usually short lived as the rope degrades.
Drilling the tree does create two wounds however usually provides a much more secure fit for the wildlife box. Those wounds are not significant and unless the tree is a very old, significant tree we would suggest the wounds are sustainable. Large old trees are less able to compartmentalise decay and therefore any wounding including drilling should be avoided.
When drilling a wildlife box to a tree with coach bolts or similar the box should be secured top and bottom and there should be a collapsible spacer which allows the tree to grow without crushing the box. There are alternatives that work such as allowing the wildlife box to slide outward on large pins as the tree expands.