WOUNDS AND WEIGHTS OF AGGREGATIONS OF RATS 
NUMBER OF 
wounds NO rth ALLEY 
BURROW 
- r 
20 
15 
10 
WEIGHT 
IWOUNDS 
1 « « 1 1 ■ ■ 1 1 r jj! 
TILE 3 N. A. 
BURROW 
WOUNDS 
384 
l. III. ill. 
BOX 25 BURROW 
BOX 23 
WEIGHT 
388 
WOUNDS 
480 
WOUNDS 
WEIGHT 
WEIGHT 
IN GRAMS 
— 1 600 
550 
500 
450 
•435 _ 
400 
■350 
— 300 
250 
bii & 8 ?? 
9 <? <? & 8 %% 
1 ah &. 5 ?? 
1 0 <? <? &. 6 ? .? 
JAN. 1949 
JAN. 1949 
FEB. 1949 
FEB. 1949 
1 
2 
3 
4 
NUMBER OF 
WOUNDS 
25p- WEIGHT 
EAST ALLEY 
I BOX — H S6 3 LADDER 
20— 36 
15 - 
10 — 
SOUTH ALLEY 
BURROW 
- WOUNDS 
5 — 
: 42.5 
WEIGHT 
wounds weight 
•12 
#435 
WOUNDS 
■22 
BOX I 
BURROW 
WEIGHT 
BOX 33 
WEIGHT 
-1600 
458 
WOUNDS 
467 
WEIGHT —550 
— 500 
-443 — K50 
WOUNDS 
-4.6 
400 
350 
300 
250 
| At* 
6<r<* 
6?? 
4*#& 4?? 
2 ? ? 
■ DEC. 1948 
MCH 1949 1 
FEB 1949 
FEB 1949 
FEB 1949 ■ 
5 
6 
7 
8 
9 
Figure 129. — Comparative differences between aggregations of rats whose past histories differ. Groups between which the 
major comparisons are intended are set off by heavy bars at the base of the histograms. The four sets of aggregations 
are: 1 and 2; 3 and 4; 5 and 6; and 7, 8 and 9. Within each grouping the aggregation with the most favorable past 
history is placed on the left. Each individual is represented by a vertical bar. Means are indicated by horizontal 
lines cutting across the histograms. Three trends stand out: (1) fewer wounds, (2) greater weight, and (3) more females 
among those aggregations with the more favorable past histories. These are some of the aggregations as they existed 
prior to the reorganization of group; at the beginning of the 1949 spring breeding season. They show that even during 
the winter, when breeding had ceased and fighting was reduced, there were marked differences even between neighboring 
aggregations. 
returned to the place of their birth up until the 
beginning of the 1949 breeding season. Of these 
males, 786 weighed from 100-150 grams more than 
any of these five males during May 1949 despite 
the fact that he was younger than they. The 
advantage of increased size is reflected by the fact 
that during the reorganization of the population 
coincident with the beginning of the breeding 
season, male 786 moved to a more favorable 
situation and assumed control of Area III, whereas 
the five smaller males became members of the 
lower ranking colonies h, j, and k. 
The formation of colony e epitomizes the results 
of many of the forces determining social oranization 
in the Norway rat. 
209 
