Johnston T D, Gottlieb G
Dev Psychobiol. 1985 May;18(3):261-71. doi: 10.1002/dev.420180306.
If Peking ducklings are given social experience with agemates after their initial exposure to a maternal imprinting model (a stuffed mallard hen) their subsequent maternal preferences in simultaneous choice tests are different from those of isolate-reared ducklings. Early in development (at 48 hr after hatching), they show a visual preference for the mallard over a redhead model, a difficult discrimination that isolated birds do not make (Experiment I). However, later in development (at 72 hr after hatching) the social experience interferes with the birds' maternal preferences, in that socially reared birds do not show a visual preference for the mallard over a pintail model, a preference that isolated birds do show at that age (Experiment II). It was found that it is the later social experience with agemates (between 48 and 72 hr) that actively interferes with the preference for the mallard model, because birds that have had only early social experience with agemates (between 24 and 48 hr) prefer the familiar mallard to the pintail model at both 48 and 72 hr (Experiment III). The conventional view of visual imprinting is that it serves to establish a maternal bond that does not require further experience with the mother to be maintained. Our results suggest that in the natural situation, where potentially interfering social stimulation is provided by siblings, continual exposure to the mother may be necessary to maintain the maternal bond even after it has been established.
如果北京鸭在初次接触母性印记模型（一只填充的绿头鸭母鸡）后与同龄伙伴有社交经历，那么它们在同时选择测试中随后的母性偏好与单独饲养的鸭子不同。在发育早期（孵化后48小时），它们在视觉上更偏好绿头鸭而非红头鸭模型，这是一种单独饲养的鸭子无法做出的困难辨别（实验一）。然而，在发育后期（孵化后72小时），社交经历会干扰鸭子的母性偏好，因为群居饲养的鸭子在视觉上并不更偏好绿头鸭而非针尾鸭模型，而单独饲养的鸭子在那个年龄会表现出这种偏好（实验二）。研究发现，正是后期与同龄伙伴的社交经历（在48至72小时之间）积极干扰了对绿头鸭模型的偏好，因为仅在早期（24至48小时之间）与同龄伙伴有社交经历的鸭子在48小时和72小时时都更偏好熟悉的绿头鸭而非针尾鸭模型（实验三）。视觉印记的传统观点是，它用于建立一种母性联系，这种联系不需要与母亲有进一步的经历就能维持。我们的结果表明，在自然情况下，兄弟姐妹会提供潜在的干扰性社会刺激，即使母性联系已经建立，持续接触母亲对于维持这种联系可能也是必要的。
