Why did Mowat pee the area as wolves do in Never Cry Wolf?

From the text:

Staking the land turned out to be rather more difficult than I had anticipated. In order to ensure that my claim would not be overlooked, I felt obliged to make a property mark on stones, clumps of moss, and patches of vegetation at intervals of not more than fifteen feet around the circumference of my claim. This took most of the night and required frequent returns to the tent to consume copious quantities of tea; but before dawn brought the hunters home the task was done, and I retired, somewhat exhausted, to observe results.