Female mammals often demonstrate a rapid initiation of maternal responsiveness immediately after giving birth, as a result of neuroendocrine changes that occur during pregnancy and parturition. However, fathers and virgins of some species may display infant care similar to that performed by mothers but without experiencing these physiological events. In biparental species, in which both mothers and fathers care for their offspring, both sex and age may affect parental motivation, even in adult virgins. We examined the effects of sex and age on parental motivation in the California mouse, a monogamous, biparental rodent. We compared parental motivation of male and female virgins in both mid- and old adulthood using two new tests - a T-maze test and a rain test - as well as in standard parental-behavior tests. Adult virgin males were more parentally motivated than adult virgin females in both the T-maze test and the parental-behavior test, but parental motivation did not differ markedly between middle-aged and older adults of either sex. These findings suggest that sex differences in parental motivation in adult virgins are similar to those observed in other biparental rodents, and indicate that the T-maze test may be useful for evaluating parental motivation in this species.

中文翻译：

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性别和年龄对成年加州处女小鼠父母动机的影响

由于怀孕和分娩期间发生的神经内分泌变化，雌性哺乳动物通常在分娩后立即迅速启动母体反应。然而，某些物种的父亲和处女可能会表现出与母亲相似的婴儿护理，但没有经历这些生理事件。在双亲物种中，母亲和父亲都照顾他们的后代，性别和年龄都可能影响父母的动机，即使是成年处女也是如此。我们研究了性别和年龄对加州老鼠（一种一夫一妻制的双亲啮齿动物）的父母动机的影响。我们使用两项新测试——T 迷宫测试和降雨测试——以及标准的父母行为测试，比较了中老年男性和女性处女的父母动机。在 T 迷宫测试和父母行为测试中，成年处女男性比成年处女女性更有父母动机，但父母动机在任何性别的中年人和老年人之间没有显着差异。这些发现表明成年处女的父母动机的性别差异与在其他双亲啮齿动物中观察到的相似，并表明 T 迷宫测试可能有助于评估该物种的父母动机。