Behavior i 
1983] 
Herbers — Social Organization in Leptothorax 
371 
Table 5. Synopsis of one-step transition probabilities among worker behaviors. 
Entries indicate the number of nonzero transitions from Behavior i to Behavior j 
observed over three colonies. 
Behavior j 
Personal 
Brood 
Social 
Physical 
Provision- 
Category 
Behavior 
Care 
Inter- 
Main- 
ing 
actions 
tenance 
Personal Behavior 
9 
20 
15 
8 
9 
Brood Care 
16 
33^ 
6“ 
2 ~ 
0“ 
Social Interactions 
14 
8 
17+ 
0“ 
2' 
Physical Maintenance 
7 
2“ 
r 
7+ 
r 
Provisioning 
8 
0" 
2~ 
3~ 
21 + 
^ more than expected by chance 
“ fewer than expected by chance 
G = 55.24, 16 df, P< .001 
transition matrix therefore gave important insights to the nature of 
polyethism in L. ambiguus. However, Table 5 must be interpreted 
with caution, since it does not report linkage over several acts. 
Analysis of per-second transition probabilities cannot detect transi- 
tions between behaviors intervened by other acts. That is, over a 
relatively long period, workers may switch roles, which would not 
be disclosed by single-step transition analysis (Herbers and Cun- 
ningham 1983). While single-step transitions suggest patterns of 
polyethism, inferences must be corroborated by long-term observa- 
tions of behavior. 
Information on worker behavior over 30-minute periods is given 
in Table 6. There is indicated the number of ants (out of a total of 
57) that executed two behaviors within a 30-minute period. It is clear 
from Table 6 that behaviors provisionally assigned to different roles 
were often displayed by one worker over 30-minutes’ time. Results 
of statistical testing of Table 6 are summarized by Venn diagrams in 
Figure 2. Behaviors intersecting in this figure co-occurred more 
often than expected by chance (x^ tests) whereas sets not intersect- 
ing were observed for the same individuals at a rate no different 
from chance expectation. Thus behaviors involved in egg care were 
related, as were those concerning care of larvae and those related to 
