Table 51. — Colony g: Passage 4 burrow and its North Alley extension, April-May 1949 
Rat’s number 
Place of birth 
Maturity 
index 
May 
weight 
May 
wounds 
Surviving young (0) 
Placental 
scars 
Males: 
59 
Area III 
111.00 
395 
12 
385 
SAB 
11.40 
464 
11 
879 
SAB 
11.50 
438 
15 
Mean 
11.63 
432 
12.7 
Females: 
72 
SAB 
1.90 
378 
5 
No 
851 
Area I 
11.80 
322 
3 
No 
2 
77 
NAB 
1.00 
570 
20 
No 
691 
NAB 
1.60 
470 
9 
No 
0 
674 
NAB 
1.58 
471 
4 
No .... 
7 
792 
NAB 
11.63 
406 
1 
No 
9 
894 
NAB 
1.67 
486 
7 
No 
791 
NAB 
11.37 
396 
3 
No 
3 
886 
NAB 
1.33 
392 
0 
12 
658 
Area III 
1.90 
420 
5 
No 
9 
661 
Area III 
11.25 
458 
5 
No 
12 
370 
Area IV 
11.17 
3 
No 
42 
NAB 
0) 
Mean 
1.93 
413 
5. 4 
6. 8 
1 She is a senescent female too old to breed. 
Table 52. — Colony j: North Alley Burrow, April- 
May 1949 
Rat’s 
No. 
Place of 
birth 
Maturity 
index 
May 
weight 
May 
wounds 
Males: 1 
74 
SAB 
1.68 
468 
62 
66 
SAB 
I 73 
445 
42 
897 
SAB 
1.50 
473 
16 
99 
SAB. 
II 00 
430 
3 
696 
NAB 
II 22 
435 
11 
757 
Area I . . . 
III 00 
390 
9 
52 
Area II ... . 
11.20 
470 
22 
660 
Area III . . . 
1.50 
478 
14 
464 
Area IV .... 
11.80 
446 
16 
Mean . . 
11.07 
448 
21.7 
Females: 
659 
Area III. . . 
11.83 
413 
16 
1 Male 69, born at SAB., M.I.: 1.40, probably belonged 
to this group. He was found partially eaten by other rats 
on May 26, 1949, along the path from the Food Pen to the 
North Alley Burrow. 
The nearly all-male aggregation, designated as 
colony j, inhabited that portion of the burrow 
which had disintegrated into the most isolated 
parts. As shown in table 57, these males repre- 
sented so many places of origin that colony j had 
the lowest homogeneity index (p. 214) of any of 
the colonies. This lack of common background 
is presumed to be a contributing factor in the lack 
of maintaining tunnels between adjoining nest 
cavities. The unkempt nature of their nests points 
to the fact that the members of socially disorganized 
groups lose the motivation or ability to maintain 
repair of the burrow system or to expand it. Actu- 
ally this section of the North Alley Burrow had 
been disintegrating even during 1948 while female 
42 and her several litters lived here. Compare 
figures 25 and 26. Therefore, the important point 
of interest may be simply the aggregating of these 
low-ranking males at this disintegrating burrow. 
Most of them had certainly been forced from more 
favorable localities. To what extent rats of dis- 
turbed past history are attracted to each other is 
unknown. The only female residing with these 
males was slower growing than any in the adjoining 
North Alley Extension of the Passage 4 burrow. 
211 
