Females of many vertebrate species are territorial. However, few studies have been performed on territorial aggression and its hormonal bases in females. The present study determined whether dwarf hamster females (Phodopus campbelli) display territorial aggression and the role that estradiol (E2 ) and progesterone (P4 ) play in this behavior. Two experiments were carried out. First, 28 virgin females were mated with sexually inexperienced males. The females were submitted to oviduct ligation 2 weeks before mating to prevent pregnancy. After 15 days of mating, 16 out of 28 females were submitted to resident-intruder tests, whereas the remaining 12 females were nonconfronted. Blood samples were collected 30 min after the aggression tests to determine E2 and P4 by ELISA. In the second experiment, 40 females were mated with vasectomized males. Thirty days after mating, 30 dwarf hamsters were subjected to ovariectomy; 10 were nontreated, 10 were treated with E2 , and 10 with P4 . The remaining 10 were sham-operated. All females were submitted to resident-intruder tests, and blood samples were taken to quantify E2 and P4 . In the first experiment, 87.5% of dwarf hamster females displayed territorial aggression, and in the second, 100% of females were aggressive. Ovariectomy and ovariectomy plus E2 or P4 replacement did not affect aggressive territorial behavior. These results showed that this species' females are territorial, and this behavior is not dependent on ovarian steroid hormones.

中文翻译：

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雌性侏儒仓鼠（ Phodopus campbelli ）的领土侵略：一种荷尔蒙方法

许多脊椎动物物种的雌性具有领地意识。然而，很少有关于女性领土侵略及其荷尔蒙基础的研究。本研究确定了雌性侏儒仓鼠（Phodopus campbelli）是否表现出领土侵略以及雌二醇（E2）和孕酮（P4）在这种行为中所起的作用。进行了两个实验。首先，28 名处女雌性与性经验不足的雄性交配。在交配前2周对雌性进行输卵管结扎以防止怀孕。交配 15 天后，28 只雌性中有 16 只接受了常驻入侵者测试，而其余 12 只雌性则没有遇到。在攻击性测试后 30 分钟收集血样以通过 ELISA 确定 E2 和 P4。在第二个实验中，40 只雌性与已切除输精管的雄性交配。交配后30天，30只侏儒仓鼠接受了卵巢切除术；10 人未经治疗，10 人接受 E2 治疗，10 人接受 P4 治疗。其余 10 个是假手术。所有女性都接受了常驻入侵者测试，并采集了血液样本以量化 E2 和 P4。在第一个实验中，87.5% 的雌性侏儒仓鼠表现出领土侵略性，而在第二个实验中，100% 的雌性具有侵略性。卵巢切除术和卵巢切除术加 E2 或 P4 替代不影响侵略性的领土行为。这些结果表明，该物种的雌性具有领地意识，这种行为不依赖于卵巢类固醇激素。所有女性都接受了常驻入侵者测试，并采集了血液样本以量化 E2 和 P4。在第一个实验中，87.5% 的雌性侏儒仓鼠表现出领土侵略性，而在第二个实验中，100% 的雌性具有侵略性。卵巢切除术和卵巢切除术加 E2 或 P4 替代不影响侵略性的领土行为。这些结果表明，该物种的雌性具有领地意识，这种行为不依赖于卵巢类固醇激素。所有女性都接受了常驻入侵者测试，并采集了血液样本以量化 E2 和 P4。在第一个实验中，87.5% 的雌性侏儒仓鼠表现出领土侵略性，而在第二个实验中，100% 的雌性具有侵略性。卵巢切除术和卵巢切除术加 E2 或 P4 替代不影响侵略性的领土行为。这些结果表明，该物种的雌性具有领地意识，这种行为不依赖于卵巢类固醇激素。