THE HONEY-GUIDES 67 



Then the honey-guides get a share of the wax from the leavmgs of 

 their abler predatory associates. In this way, to put the matter 

 briefly and crudely (and we do not have the data with which to ex- 

 press it more accurately), these animals become familiar and im- 

 portant to the birds. 



As pointed out to me by Chapin (in litt.), in a somewhat similar way 

 monkeys seem to have become important to hornbills of the genus 

 Tropicranus because they scare out large insects; similarly, large 

 grazing mammals became attractive to cattle egrets (Bubulcus), 

 cowbirds (Molothrus), and flycatchers (Alachetornis) because they 

 flush grasshoppers and other insects, and they became attractive to 

 oxpeckers {Bwphagus) because they carry ticks. ^^ In these cases the 

 birds do not deliberately attract men to their large mammalian 

 comrades. There is, of course, no reason why they should, for men 

 would not thereby increase their food supply. The fact that in I. 

 indicator and /. variegatus the birds do "lead" humans bears out the 

 contention that to these birds a potential foraging symbiont is merely 

 any creature associated from previous experience (?) with the opening 

 of bees' nests, and is therefore only an extension of the ratel-guiding 

 association. The human element has served to bring the habit 

 forcibly to the attention of naturalists, but is, in itself, of lesser 

 interest than the basic symbiotic tendency of which it is a partial 

 displacement. 



The displacement of a wild mammal by a human m part of the life 

 of a bird is not peculiar to honey-guides. A rouglily analogous case 

 has been reported for the European robin, Erithacus rubecula, by Geyr 

 von Schweppenberg (1951). He wTites that this bird appears to have 

 a tendency to come to a large animal — horse, deer, badger, or bear^ — 

 and even to a man working in the woods; the apparent reason for this 

 trait being that the robin thereby obtains insects scared up incidentally 

 by the mammal's activities. That this tendency in the robin is imiate 

 rather than learned is suggested by its short life-span and solitary 

 habits. It would seem that this feeding habit may well be older than 

 the possible association with humans; in other words, that it started 

 with grazing quadrupeds and later vvas extended to include humans in 

 similar situations. We know nothing of the longevity of honey-guides, 

 but they do parallel the case of the robin in that they are rather 

 solitary, and in that they will come to humans out in the bush but 

 not to men in native villages or compounds. 



While not of the same degree of pertinence, it may not be out of 

 place to recall that in his general, philosphicol discussion of the roles 

 of the various "companions" as releasers of behavior, Lorenz (1935) 



'2 Rand (1954) has recentlj' brought together many types of feeding relation- 

 ships. 



