"Quite likely you have," was the reply, "since such is the case. The kingfisher has been a familiar bird in all ages, as he is not at all shy, and, when undisturbed, he will remain until you walk quite close to him. As his name implies his chief food is fish of his own catching, but he does not disdain the mouse or other animal small enough for him to grapple with. Some varieties make their nests in hollow trees, but the majority dig holes in banks, unless they can find unoccupied ones that were made by some burrowing animal and abandoned. Whether the bird appropriates a deserted nest or makes one of its own, it always has it with the entrance sloping upward, so that the rain cannot enter. Moisture is fatal to the eggs, and the kingfisher takes good care that they shall not be injured." The grass bore indications of the presence of the hippopotamus, or river-horse; though Fred remarked that he could not properly be called a river-horse at this point, seeing that he inhabited a lake. It did not make much difference what he was called, as he was probably quite indifferent to what was said of him as long as he was left uninjured. They followed some of the hippo tracks, in the hope of discovering the animal that made them, but without success. The tracks in every instance led to the water, and nobody had the slightest desire to go below the surface to see how the hippo got along. Just as they were turning back from the last of the traps Fred espied some birds flying in the air too far off to be worth a shot; he called the attention of the Doctor to the birds, and the latter, after a brief glance at them through his glass, said they were fish-eagles. [Illustration: FISH-EAGLE ON A HIPPOPOTAMUS TRAP.] "Yes, fish-eagles," as he took another look at them, "and one has just lighted on the top of a low tree. No, it's a trap for a hippo; and so the island, if not inhabited, is visited by people who do not live far away." Fred wanted to go in pursuit of the eagle, as he desired to preserve its skin, as a trophy of his skill in hunting; but the Doctor said the ground was too wet and soft for them to go there. "And besides," he continued, "there may be some one watching the trap; and, if so, he might resent our visit and send an arrow or a spear, without waiting for us to explain our intentions."