Star Hunter by Andre Norton

Moisture from the night's rain hung on the tree leaves, clung in globules to Rynch's sweating body. He lay on a wide branch trying to control the heavy panting which supplied his laboring lungs. And he could still hear the echoes of the startled cries which had come from the men who had threaded through the woods to the up-pointed tail fins of the L-B.

Now he tried to reason why he had run. They were his own kind, they would take him out of the loneliness of a world heretofore empty of his species. But that tall man -- the one who had led the party into the irregular clearing about the life boat --