What does the trapper do during the buffalo stampede in James Fenimore Cooper's The Prairie to stay safe?

In the novel, Natty Bumppo is the trapper, or "the old man." To stay safe during the buffalo stampede, he first shoots a buffalo at the forefront of the stampede and then runs towards the approaching herd with his arms raised. Then, standing firm, he divides the stampede into two columns. Captain Middleton and Paul Hover (the bee hunter) join him in this protected area, and this is how the trapper and his friends stay safe.
Accordingly, the buffalo stampede occurs in Chapter 19. Prior to the stampede, the trapper (Natty) points out a flight of vultures traveling across the sky. He tells Captain Duncan Middleton that the appearance of vultures usually precedes a buffalo stampede.
In short order, the first lines of buffalo make their way through the prairie; eventually, the plains are filled with herds of bison. Natty's companions are entranced by the spectacle, but he has seen such a scene many times in his life. He advises his friends to prepare for the buffalo onslaught, warning them that hiding will prove fruitless.
First, Inez and Ellen, the two women, are placed at the edge of the thicket, farthest from the approaching herd. Asinus, Doctor Battius' donkey, is placed in the center. Meanwhile, Natty and his three male companions "divided themselves in such a manner as they thought would enable them to turn the head of the rushing column, should it chance to approach too nigh their position." Eventually, however, Natty's companions panic and call on Natty to save them.
This is when Natty aims at the buffalo at the forefront of the stampede and shoots. The buffalo falls dead, and this alerts the rest of the herd to the presence of men on the plain. At this point, Natty rushes toward the approaching herd with his arms raised. Intimidated by Natty's sudden appearance, the herd abruptly comes to a stop. Eventually, threatening bellows from the rear cause the stampede to begin anew. This time, however, the herd divides into two columns around Natty, Middleton, and Hover.
The three are able to hold off the beasts from breaking their ranks for a time. Eventually, however, the buffalo push closer and closer to the men, and the situation becomes dire. At this point, Asinus saves the day. With a loud bray, he scatters the frightened beasts. The bison change course (away from the thicket they were approaching), and the stampeding columns eventually reunite at the opposite end of the thicket.

All their efforts would have proved fruitless, however, against the living torrent, had not Asinus, whose domains had just been so rudely entered, lifted his voice, in the midst of the uproar. The most sturdy and furious of the bulls trembled at the alarming and unknown cry, and then each individual brute was seen madly pressing from that very thicket, which, the moment before, he had endeavored to reach, with the eagerness with which the murderer seeks the sanctuary. As the stream divided, the place became clear; the two dark columns moving obliquely from the copse, to unite again at the distance of a mile, on its opposite side.