"That's so," assented Jack; "I must be pretty stupid not to be able to think of these things."
"Well," replied Hugh, "of course you have to think, and boys don't always stop to do that. Men, after they have lived a good many years find that they have to do it. But this is what I wanted to say about the power of game to recognize danger from man; a deer knows that there is danger only from living things, and he knows also that only living things move, so that if he sees anything make a sudden motion he knows that he must be on the lookout."
All day they traveled on through a broad valley, and toward night camped at the foot of a high, bare hog-back running north and south, one of the foothills or spurs of the main range to the north. There was a good spring where they camped, and quite a wide stretch of level prairie, in which were half a dozen large alkali lakes, and on these lakes were great numbers of water fowl. Some of them were so large that Jack thought they must be geese, and getting his field glasses out of the packs he looked at them and found that they really were geese.
"How is it, Hugh," he said, "that geese are found here as late in the season as this? Here it's nearly the first of June, and it seems to me all geese ought to have passed north to their breeding grounds before this."
"I'll allow," answered Hugh, "that the geese ought to be on their breeding grounds by this time, but why do you say they ought to be up north?"
"Why", said Jack, "I thought all geese went north into Canada to breed, except a few that breed in northern Montana, right close to the Canada line."
"Well," said Hugh, "there's where you are mistaken. The geese breed right here in these mountains, and quite a way south of here, too. Then you know yourself, you've seen them breeding on the Missouri River, although that is pretty well north, of course."
"Yes," said Jack, "I've seen them up north, but I didn't suppose that any of them stayed as far south as this."
"That's a mistake," said Hugh. "In old times they used to breed on the prairies as far south as Kansas, and maybe still further south. Many a time I have seen them breeding in Nebraska and in northern Kansas, and from that away north as far as I've been. Swans, too, used to breed in the same country. The reason they don't breed there any more is because the white people have come in and killed them at all times of the year, and so they go on to a country further away from where the white people are."
"Well, live and learn," said Jack. "I got my knowledge about that from the books, but I guess the books don't know everything?"