100 
Psyche 
[March 
Many location and activity variables were tested in the six species 
for their potential as taxonomic characters, including cosine-fitted 
rhythm parameters as well as simple hourly values (Table 1). For 
most of them the species difference was significant. 
By contrast with the fitted-rhythm and other processed variables, 
the hourly variables taken singly can indicate only the level (of 
activity or location) at a given hour. In the aggregate they become 
more meaningful. For example, scanning the hourly P values in 
Table 1 indicates one time of day to be more important than another 
in distinguishing species. Or more formally, a multivariate approach 
can compare in terms of the whole hourly pattern. MANOVA con¬ 
firmed the overall species difference, and multidiscriminant analysis 
made it possible to discriminate each species from the others. It 
should be noted again that the purpose here is to examine these 
variables as taxonomic characters, rather than to develop a classifi¬ 
cation. 
Nearly every one of the processed variables was abstracted from all 
the hourly values of a given type of assay, and hence should have high 
information content. So it is noteworthy that the groups of hourly 
variables seemed to distinguish species about as well as the group of 
processed ones. However, if some of both kinds were included in the 
same analysis, the most highly weighted were processed variables, 
most highly weighted were processed variables. 
How might the list in Table 1 be compared with catalogues of ant 
behavior, such as that of Wilson (1976)? In the first place, the varia¬ 
bles reported here were population rather than individual phe¬ 
nomena. Secondly, many of them are derived rhythm parameters 
(e.g., acrophase or amplitude) of certain items of behavior, rather 
than the behavior itself. The hourly variables, on the other hand, do 
represent behavior more directly (e.g., the number active or the 
number in the hot location, at a given point in time). Any compre¬ 
hensiveness of catalogue (e.g., for choice of heat or light or location 
in the nest assembly) would require more habitat complexity, and 
preferably field studies as well. But such comprehensiveness is 
needed to facilitate behavioral comparisons at species or higher 
levels (Wilson 1976). 
In summary, this study suggests a variety of rhythm-related char¬ 
acters that might be observed in laboratory or field, whether single 
hourly values, composite hour-by-hour patterns, or fitted rhythm 
parameters. 
