About one hundred yards along the path we got to a deep valley, on the far side of which the path led into some very thick bushes. Rather than go through these, I decided that if we walked along the bottom of this valley we could climb up again and rejoin the path on the far side of the bushes. As I climbed down into the valley a bird flew off a rock on which I had put my hand. On looking at the spot where the bird had risen I saw two eggs. They were a kind that I did not have in my collection, so I placed them carefully in my bag, wrapped in a little dry grass. As we went further down the valley the sides became steeper and not far from where I had entered it. I came to a drop of about twelve to fourteen feet. The water that rushed down all these small valleys in the rainy season had made the rock as glass. As it was too deep to climb down, I handed my gun to one of the men and slid down it. My feet had hardly touched the sandy bottom when the two men jumped down, one on each side of me. They quickly gave me the gun and asked me if I had heard the tiger. Actually, I had heard nothing, perhaps because of the noise I made sliding down the rock. The men said they had heard a tiger growling somewhere nearby, but they did not know from which direction the noise had come. According to the passage we know that ______.