50 YEARS AGO

Among the strangest forms of animal behaviour is that of the honey-guides, African birds distantly related to the American woodpeckers, which ‘guide’ men, baboons and ratels (honey-badgers) to the nests of wild honeybees—supposedly so that these nests can be broken open. A study of the behaviour is described by Dr. Herbert Friedmann, U.S. National Museum curator of birds, in a bulletin issued by the Smithsonian Institution, Washington... “When the bird is ready to begin guiding, it either comes to the person and starts a repetitive series of churring notes or it stays where it begins calling these notes and waits for the human to approach it more closely... As the person comes to within 15 to 50 feet from it, the bird flies off with an initial conspicuous downward dip, and then goes off to another tree, not necessarily in sight of the follower; it is more often out of sight than not. It waits there, churring loudly until the follower again nears it, when the action is repeated. This goes on until the vicinity of the bees' nest is reached... It waits for the follower to open the hive and usually remains until the person has departed with a collection of honeycomb, when it comes down to the plundered nest and begins to feed on the bits of comb left strewn about.”

From Nature 28 January 1956.

100 YEARS AGO

“Sounding Stones” — It may be of interest to add to the list of musical stones provided by your correspondents another limestone, viz. the very hard, crystallized, coral rock of the coasts of British East Africa. Among the bizarre forms assumed by these rocks under the erosion of the sea, isolated pillars with projecting arm at the top, like a gallows or an inverted capital “L,” are common in places. This horizontal arm in many cases gives a clear musical note when struck with a stone or hammer, being thus a ready suspended natural gong.

From Nature 25 January 1906.