Hjelm organises ropes and harnesses and we climb two kauri rickers to get a canopy-eye view. It is both exhilarating and poignant to be aloft in these princes of the forest—like being up the gently swaying mast of a yacht. I reach out to touch a female kauri cone, a spiky green golf ball borne at the tip of a branch, and lean close to the trunk to get a whiff of fragrant conifer sap where a branch has dropped, leaving a clean scar sealed with sticky gum. I think of the gum climbers who worked in these forests more than a century ago. No fancy climbing gear for them. They scaled mature kauri with just a pair of sharp hammers and spikes in the toes of their boots, risking their lives for the cache of gum that might lie in the crown.