Though some of these associations are evidently fairly common and chosen deliberately by the birds--and one can easily visualize how the protection works--field observations as to the natural enemies against which they are effective, and how effective they are, are largely lacking. Usually the records are something like those of Van Rossem for the Giraud's flycatcher in El Salvador, in which he points out that this bird usually nests in certain mimosa trees armed with numerous heavy, curved thorns. These thorns are hollowed out and inhabited by swarms of small but extremely hostile antlike insects, so that the nest is well protected. However, the effectiveness of ant and bee protection against human predation can be seen in the following. Take the case of Mr. M. E. W. North, who arranged a rope to climb to a fish eagle's nest in East Africa. He had gotten about fifty feet up and was considering going out on the big limb on which the nest was, when he noticed a wild bee on his sleeve. Realizing that he was disturbing a wild-bee hive, and knowing that the sting of these vicious bees can be dangerous, fatalities having been reported, he came down his rope at express speed, crashing through projecting branches and brambles. Reaching the ground, he freed himself from the rope and fled to a safe distance, considering himself lucky to have received only three stings. On another occasion, again in East Africa, Mrs. R. E. Moreau attempted to reach a hawk's nest to measure the eggs, but when she was up in the tree, savage, biting red ants drove her out. BIRD GUIDES TO HONEY [Illustration] In Africa there are birds which lead men to honey. They are called honey-guides and their family name, Indicatoridae, has the same idea incorporated into it. Though there are several species of these small, dull-colored birds, which are related on the one hand to woodpeckers and on the other to barbets, it is only one species, the common or black-throated honey-guide that is well known as a guide to honey. The traveler in the country may find one of these birds chattering and flying ahead of him. The natives, who know this bird well and favorably will tell the traveler to follow; it will lead to a bee tree. The native, as he follows this guide, gives occasional whistles, as if to encourage the bird. The bird continues, flying from perch to perch, ahead, and chattering noisily. Sometimes it may return to see if the men are following; sometimes it remains chattering on its perch until the followers catch up. Finally the bird will go no farther. It flies about aimlessly and allows one to approach closely. This is the spot. In a hole in the tree trunk, or in the ground nearby the bees' nest is to be found. When the beehive is opened, and the honey taken, the honey-guide will eat the comb that is left, and apparently it is for this that the complicated behavior of leading of man to the beehive is developed.