Mayer A D, Rosenblatt J S
J Comp Psychol. 1984 Jun;98(2):177-88.
Changes in maternal responsiveness during late pregnancy were traced by exposing females to foster pups (15-30-min tests) under conditions favoring the rapid initiation of maternal behavior. Groups were tested when nonpregnant or on Days 17, 20, 21, or 22 of pregnancy (Day 22 = parturition). Nulliparous females were compared with primiparous and with "experienced breeders." Nest defense was observed by introducing unfamiliar males (2-min tests) on Day 22. Results focused attention on three periods: (a) Days 17-20, when maternal responsiveness was lower than in the nonpregnant condition, (b) Day 21, when maternal responsiveness returned to or rose above nonpregnant levels, and (c) on Day 22, the 3.5 hr prior to delivery, during which 90% of females almost immediately retrieved, gathered, and tended foster pups and during which 92% attacked the unfamiliar intruders. (Attacks were rare earlier.) Maternally experienced females were more responsive to pups than nulliparous females when nonpregnant and throughout late pregnancy, but both groups were equally likely to show prepartum aggression.
在有利于快速引发母性行为的条件下，通过让雌性接触寄养幼崽（15 - 30分钟测试）来追踪妊娠后期母性反应性的变化。在未怀孕时或怀孕第17、20、21或22天（第22天 = 分娩）对各组进行测试。将未生育的雌性与初产雌性以及“经验丰富的繁殖者”进行比较。在第22天通过引入陌生雄性（2分钟测试）来观察巢穴防御行为。结果聚焦于三个时期：(a) 第17 - 20天，此时母性反应性低于未怀孕状态；(b) 第21天，此时母性反应性恢复到或高于未怀孕水平；(c) 在第22天，分娩前3.5小时，在此期间90%的雌性几乎立即找回、聚拢并照料寄养幼崽，且92%的雌性攻击陌生入侵者。（早期攻击行为很少见。）有母性经验的雌性在未怀孕时以及整个妊娠后期对幼崽的反应比未生育的雌性更敏感，但两组在产前攻击行为上的可能性相同。
