1981] 
Levings & Traniello — Territoriality in Ants 
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depend upon whether or not nest sites are farther apart or closer 
together than this distance. We predict one of 2 patterns: (1) nests 
will be more overdispersed than potential nest sites (Case 3a) or (2) 
although nests may be clumped in space, foraging ranges which are 
asymmetric and which partition foragers will develop (Case 3b). If 
potential nest sites are farther apart than twice r, then nests will be 
distributed only with respect to potential nest sites. The effects of 
habitat heterogeneity will depend upon the scale and extent of the 
patchiness in relation to the foraging range of a species. If patches 
hold several to many colonies, then clumps of nests which are 
overdispersed within the clump are predicted. Smaller patches in 
complex mosaics will not generate predictable nest distributions 
unless the arrays of patches are very regularly distributed. 
The effect of adding more species to the system will depend upon 
the species. Generally, in multi-species systems, the level of repul- 
sion observed between co-occurring species should be directly 
proportional to the amount of overlap in resource use. Species 
utilization curves can range in overlap from 0 to essentially com- 
plete ecological identity (100% overlap). Predicted spatial patterns 
will clearly depend on the actual distribution of species. If two or 
more species with identical requirements and foraging radii occur in 
the same area, interactions within and between species should be 
equally strong. In this case, the pattern of nest distribution predicted 
is random for any one species (Franks 1980; Levings and Franks 
1982). Nests should be overdispersed, but each species is distributed 
with respect to every other species (i.e., nests of all species are 
treated as equivalents). In addition, there should be no pattern in 
the species identity of nearest neighbors (Case 4). Removal of any 
one species should have the effect of the removal of a nest at random 
from an overdispersed array; the degree of observed overdispersion 
should decrease. The spatial dispersion of any one species in such an 
array should tend to look like a low density nest population (Case 
2), but the history of the area may cause any type of pattern under 
different conditions. 
If two or more species have the same foraging radius but do not 
overlap 100% in resource requirements, intraspecific interactions 
should be stronger than interspecific interactions (Case 5). We 
predict that (1) the entire array will be overdispersed and (2) each 
species will also be overdispersed from itself. Franks (1980) and 
