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Psyche 
[Vol. 94 
exhibit solitary hunting and column raiding respectively, and 
members of the genus Pachycondyla exhibit a range of hunting 
strategies. Furthermore, representatives of each of four tribes hunt 
in well-coordinated raids (Table 1). These data emphasize that 
foraging characteristics are the product of the unique selective pres- 
sures facing each species. The evolution of these characteristics is 
not governed by anatomical constraints, e.g. all members of the 
sub-tribe Poneriti seem to have the exocrine glands necessary for 
recruitment, but only some of them hunt in groups. In addition, 
some solitary-hunting species have recruitment capabilities which 
they do not use during foraging, e.g. Diacamma rugosum, Dino- 
ponera gigantea and Pachycondyla (—Neoponera) apicalis use 
tandem-running during nest emigration only (Fukumoto and Abe, 
1983; Overal, 1980; Fresneau, 1985). 
Wilson (1958) suggested that group hunting only becomes selec- 
tively advantageous with respect to certain prey preferences. This is 
evident for species which prey on large arthropods or on the brood 
of other ants. However, strictly termitophagous species include both 
solitary and column hunters, i.e. a number of strategies are approp- 
riate to exploit this strongly-clumped prey. Column raiding appears 
to have evolved a number of times and from different behavioral 
antecedents (Furthermore, different exocrine glands are involved in 
recruitment.), and this term thus describes a range of “variations on 
one theme”. Indeed in some species, group raiding is followed by 
solitary retrieving of the prey. The occurrence of group hunting is 
unlikely to be related to one ecological factor only. 
There has not been a phylogenetic trend towards the elaboration 
of patterns of cooperation and recruitment during predation in the 
Ponerinae, and these characteristics can vary from species to species 
regardless of the nature of the reproductive system. Indeed, group 
foraging is characteristic of the genus Leptogenys, and this behav- 
iour is unaffected by the change to gamergate breeding which has 
occurred in L. schwabi (M. Zini, in prep.). Thus we reject the possi- 
bility that the simple hunting strategy seen in O. berthoudi is a 
secondary modification caused by a reduction in altruism in colo- 
nies with numerous matrilines. We note that solitary-hunting spe- 
cies with a highly-specific diet are more vulnerable to seasonal 
fluctuations in prey availability. Rather than implying that elimina- 
tion of the queen caste would result in a simplification of social 
