Modification of ducklings' filial behavior by aversive stimulation.

Abstract

Three experiments examined the effects of aversive stimulation in the context of imprinting. In Experiment 1, newly hatched ducklings were electrically shocked in either the presence or absence of an imprinting stimulus, and both their tendency to follow the stimulus when it was presented alone and their preference for it over novel stimuli were subsequently assessed. The results indicated that the shock enhanced the subjects' tendency to follow the imprinting stimulus in the nonchoice situation regardless of whether the ducklings were shocked in its presence or absence. If, however, the electrical shocks were associated with the presence of the imprinting stimulus, they also reversed the ducklings' usual preference for the imprinting object over the novel stimuli. Comparable effects were obtained in the second experiment in which 5-day-old ducklings were electrically shocked in either the presence or absence of a novel, fear-eliciting imprinting stimulus. In Experiment 3, electrical shock was administered to newly hatched ducklings independently of their exposure to an imprinting stimulus, and it was found that, relative to older ducklings that received the same treatment, the newly hatched subjects subsequently displayed less emotionally in fear-eliciting situations. The results were interpreted as suggesting that there are at least three distinct effects of aversive stimulation in the context of imprinting-motivational, associative, and developmental.

Effects of group rearing on the control exerted by an imprinting stimulus

“…We also observed that when huddling in a corner, the subjects seldom, if ever, emitted distress calls. This is similar to an observation by Ratner (1976), who found that older ducklings, when tested individually in a novel box, either distress call and run about or crouch with their head in a corner of the box; they rarely distress call and crouch simultaneously. To take account of this, Ratner assessed crouching behavior as well as distress calling and combined these two measures to obtain a single index of the subjects' reaction to the test procedure.…”

Aggressive reactions of ducklings to a nonliving target object

“…The enhancement of forceful pecking at the target object as a consequence of early stimulation is consistent with the previous research demonstrating an increase in aggressive behavior directed at a conspecific as a consequence of early stimulation. Furthermore, the increased levels of following and distress call suppression in the early stimulation ducklings replicates a finding by Ratner (1976) that early stimulation results in the more rapid development of filial behavior.…”

Long‐term Potential for Imprinting in Ducks and Chickens

“…The first test assessed the possibility that -the adults' tendency to approach the imprinting stimulus would be enhanced in the presence of a novel, fear-inducing stimulus. Such an effect can be readily documented in newly hatched birds (Moltz, Rosenblum, & Halikas, 1959;Ratner, 1976;Sluckin & Salzen, 1961;Stettner & Tilds, 1966) and suggests that the imprinting object is a "comforting" stimulus whose presence reduces or alleviates conditions of fear or anxiety (Eiserer, 1978a).…”