||Experiment 2: Results||Page 7|
Territorial fighting was obtained in seven of the eight males and seven of the eight females. It was strongest in the males against male intruders (mean attack frequency 2.74) and weakest in females against male intruders (0.22). The data are shown in Table 2 and Fig. 2.
The motor patterns of offense were the same as those seen in competitive fighting, but in different proportions, depending upon the sex of the animal and the sex of its opponent. Bite-and-kick attack was seen primarily in resident males against male intruders, while a biting attack was seen most commonly in the attack of a resident female against a female intruder. Offensive sideways posture was seen most often in resident males against male intruders.
Territorial fighting was dependent upon the sex of the opponent. Both males and females attacked intruders of the same sex more than intruders of the opposite sex. The interaction of sex of test animal and sex of intruder was significant in the analysis of variance (F = 14.0, p < 0.001). In the analysis of variance, none of the main effects and neither of the other two two-way interactions were significant. Offensive sideways posture by the female residents, unlike attack, was more frequent against male intruders than against female intruders.
Five of the eight DA females became pregnant during the course of the experiment. The rates of offense for the pregnant females were as follows: 1.14 bite; 0.55 bite-and-kick attack; and 0.55 offensive sideways posture. The corresponding rates for the three nonpregnant rats were higher: 1.25 bite; 0.67 bite-and kick; and 1.82 offensive sideways posture.