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[Vol. 85 
were not confounded by variation between observers, husbandry 
techniques, or colony size. 
The two species are ecologically similar. Both inhabit temperate 
forests throughout eastern North America, nest in small plant cavi- 
ties such as acorns, twigs, and hollow roots, and scavenge for 
arthropod parts. On the Huyck Preserve, L. longispinosus is more 
common, preferring deep woods, while L. amhiguus appears re- 
stricted to relatively open habitats; despite some microhabitat segre- 
gation, the two do co-occur in many places. 
A subjective analysis of their overall demeanor suggests that L. 
amhiguus is the higher-tempo species (sensu Oster and Wilson 
1978). That is, they are more excitable and appear to move faster 
than L. longispinosus. While this study was not designed to detect 
tempo differences, one set of behaviors clearly illustrated it: for the 
L. amhiguus colonies, certain workers were often stationed at the 
nest entrance. While there, they periodically roused to inspect the 
entrance, moving a few cm outside the opening before returning to 
their position. This combination (LOT, MOT) was observed for all 
3 colonies (Table 3). By constrast, L. longispinosus workers only 
occasionally positioned themselves near the nest entrance, and the 
apparent guarding behavior was observed for only one of four colo- 
nies watched (Herbers 1982). Thus the more excitable nature of the 
presumed higher tempo species was evident in the colony etho- 
grams. 
Both species displayed a division of labor, with similar patterns of 
polyethism. Roles of brood care, social organization, and nest main- 
tenance were identified in each. For L. longispinosus, though, 
foragers comprised a unique caste whereas in L. amhiguus foragers 
displayed other provisioning behaviors as well. Moreover, in L. 
longispinosus the division of labor was much tighter: very few 
instantaneous transitions between roles were observed, most of 
them between brood care and nest maintenance (Herbers and Cun- 
ningham 1983). For L. amhiguus, transitions among roles were 
more frequent (Table 5), although less common than chance expec- 
tation. Over 30-min. periods, workers of both species switched roles, 
but again, role-switching was far more common for L. amhiguus 
than for L. longispinosus. Therefore, although specialization 
occurred in both species, division of labor was considerably tighter 
for one. 
