48 BULLETIN 208, UNITED STATES NATIONAL MUSEUM 



results in both the bird and its releaser-associate arriving at or near 

 a bees' nest. The fact that definite physiological need seems to be 

 unnecessary as a factor in bringing about the guiding behavior 

 suggests that the instinctive behavior involved is, to use a diJfferent 

 terminology, what Lorenz has termed an endogeneous stimulus 

 producing phenomenon. In an admittedly loose way, the experiences 

 of many observers recounting their observations from memory, 

 unaided by recorded data, suggest that there may be more guiding in 

 the morning than in the afternoon hours, but this is by no means an 

 invariable experience. It may be that the symbionts are more 

 active early in the day than later on, as the bhds have been known 

 to guide humans at all hours, even in the hottest part of the day. 

 As far as I know, in areas where the birds guide frequently, the only 

 times and conditions when the greater honey-guide is known to be 

 unaffected by, or at least unresponsive to, the appearance of a poten- 

 tial symbiont are (1) adult males during the hours of the day when 

 they are established on, and calling from, the call sites or stud posts, 

 and (2) any individuals, regardless of sex, age, or the season, when 

 feeding at a recently opened bees' nest. 



Nothing is known of variations in the valence of ratels or baboons 

 under different conditions, but in the case of the human symbiont it 

 seems true that the individual, or group, as the case may be, must be 

 met with in the birds' natural envkonment. I know of no case where 

 a honey-guide has come into a native village and begun to give its 

 guiding behavior. There are authentic instances of male honey-guides 

 using a tall tree on a street of a sizable town as a temporary call post, 

 but no instance of their guiding in such places. Also, there are 

 authentic instances of their coming into hunters' camps, but these 

 are temporary occupations of otherwise natural environment. Thus, 

 A. Blayney Percival (1924, pp. 347-348) writes that when a honey-guide 

 comes to a camp as it is being pitched, the natives take no notice of it 

 until the chores are done: "They try his patience, for they never 

 hurry; they know the guide will wait. ... If ignored, he will stay 

 about the camp aU day and turn up again next morning." Similarly 

 there are observations of honey-guides attending sizable groups of 

 men on the march. For example, General Bisset (1875, pp. 160-167) 

 relates that while en route with a squadron of cavalry, in addition to 

 an unstated number of infantry, in Natal in 1843, a honey-guide 

 came to them during a halt and guided some of his men to bees' nests. 



As far as I have been able to learn, ratels are solitary, nongregarious 

 animals, and I have not heard of more than two being seen together. 

 If, as seems likely, the ratel was the original symbiont, it is of interest 

 to find that the human symbiont is still effective as a releaser of 

 guiding behavior even when in aggregations. Apparently the number 



