Storm Over Warlock by Andre Norton

There were patches of light in the inner valley marking the phosphorescent plants, some creeping at ground level, others tall as saplings. On other nights Shann had welcomed that wan radiance, but now he lay in as relaxed a position as possible, marking each of those potential betrayers as he tried to counterfeit the attitude of sleep and at the same time plan out his route.

He had purposely settled in a pool of shadow, the wolverines beside him. And he thought that the bulk of the animal's bodies would cover his own withdrawal when the time came to move. One arm lying limply across his middle was in reality clutching to him an intricate arrangement of small hide straps which he had made by sacrificing most of the remainder of his painfully acquired thongs. The trap must be set in place soon!