THE HONEY-GUIDES 19 



were not more recent than the Miocene, and probably older. This 

 fits in very well with Kendeigh's general statement. 



Brood hosts 



The following generalizations must be read with the mental reserva- 

 tion that we still know nothing of the brood hosts of five of the eleven 

 species of honey-guides, and very little of those of three of the remain- 

 ing six. Of these six, the data are relatively extensive for only two, 

 the greater and the lesser honey-guides, but inasmuch as these two 

 occur in the same habitat in many parts of Africa, it is possible to see 

 what, if any, differences they reveal in their choice of hosts. The two 

 together are known to parasitize some 39 species of birds (not counting 

 subspecies), and 12 of these 39 serve as brood hosts to both. Of the 

 27 other species, a little more than half are birds with single, or at 

 most two, host records each, but some of the rest appear to reflect 

 definite differences in the range of selective parasitism preferences of the 

 two honey-guides. Nests in holes in the ground are utilized relatively 

 seldom by /. minor (3 instances out of 50 -|- host nest records), but are 

 frequently parasitized by I. indicator (44 cases out of a total of 96 host 

 nest records). Bee-eaters, hoopoes, kingfishers, and pied starlings 

 are the chief ground-tunnel nesters victimized by /. indicator, and 

 these birds are obviously far more important to the greater than to 

 the lesser honey-guide. Wliile it is true that barbets and wood- 

 peckers are relatively more favored by /. minor than by I. indicator, 

 the latter uses these hosts often enough to make it clear that they are 

 satisfactory for its purposes as well. Thus, in my files are 19 records 

 involving 5 species of barbets and 4 of woodpeckers for I. indicator 

 and over 40 records involving 9 species of barbets and 6 of wood- 

 peckers for I. minor. To put it somewhat differently, approximately 

 20 percent of the host records for /. indicator (actually 19 out of 96) 

 are for barbets and woodpeckers, while for /. minor this figure is 80 

 percent (over 40 out of 50+ records). 



The kno^vn choice of victims of I. variegatus and I. minor shows a 

 remarkable degree of sameness throughout. The data at present 

 available for the variegated honey-guide involve 11 species of hosts. 

 Of these, all but one are also parasitized by the lesser honey-guide 

 (and that one leaves something to be desired as to the identification 

 of the parasite). 



One host species in southern Africa, the yellow-throated sparrow, 

 Petronia superciliaris, is parasitized by two kinds of honey-guides 

 found there (/. indicator, I. minor) and has been suggested as a host 

 of a third (P. regulus) and even of a fourth (/. variegatus). Another 

 host species in tropical Africa, the golden-rumped tinkerbird, Pogoni- 

 ulus bilineatus, is recorded as a victim of four species of Indicator 



