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Psyche 
[Vol. 93 
FISSIONS S 
FUSIONS 
MIGRATIONS • • 
MAT JUN JUL AUG SEP 
MONTH 
Figure 3. Large-scale events occurred infrequently over the season and were 
clustered in early spring. 
These behavioral observations accord well with inferences made 
about population structure that are based on spatial distributions of 
nests and queen distribution among nests (Herbers 1986a). If the 
cyclic polydomy hypothesis is correct, then the nests used in this 
study, which had been collected in late fall, had already undergone 
colony coalition for overwintering. The units that were set out on 
the floors, then, were presumably functional, independent colonies. 
When ants from different colonies came back into contact after 
overwintering, they re-established dominance relations through 
aggressive encounters and perhaps staked out territories. Likewise, 
under spring conditions, colonies fractionated to occupy empty 
nesting sites. After a period of fusions, fissions, brood exchange, 
and the like, a spatial pattern was achieved that was largely main- 
tained throughout the rest of the summer. We expect that, had we 
been able to expose the floors to more autumn-like conditions, we 
would have observed nest fusions and colony condensations to 
increase. 
This seasonal cycle makes comparisons to other studies difficult. 
Alloway et al (1982) reported that fusion resulted in each of three 
