Need a fence? What you really need is a deadhedge.
It's a barrier made of dead branches stacked between two rows of posts. You feed it with branches, fallen limbs, and woody yard debris. Over a season it becomes denser than most commercial fencing. Over years, the bottom layers compost down and the top gets refilled with whatever you trim that week.
Wrens, robins, and ground-foraging birds nest in the structure. Hedgehogs, field mice, frogs, and toads shelter in the base. Solitary bees, ladybirds, and beetles overwinter in the cavities.
Germany has been planting deadhedges as wildlife corridors since the 1990s. The UK uses them for riverbank restoration.
A wood fence costs thousands of dollars and supports no wildlife. A deadhedge costs nothing, gets denser every year, and provides habitat for dozens of species you want in your yard anyway.