Clark AB, Lee Wh
Department of Biological Sciences, Binghamton University
Anim Behav. 1998 Sep;56(3):563-570. doi: 10.1006/anbe.1998.0831.
The begging behaviour of nestling birds appears to be the main signal telling parents how much food is needed by the brood. Not only may the accuracy of that information be reduced through exaggeration due to competition, but it may also vary with the age of the nestling. Younger nestlings may vary more in how frequently they call than older nestlings because they cannot discriminate stimuli as well. Thus, even if 'honest', begging from younger nestlings could be a less reliable hunger signal than that from older nestlings. We tested the prediction that parents should respond less to the increased frequency of begging from very young versus older nestlings by playing back begging calls at the nests of both younger (</=5 day) and older (>/=6 days) red-winged blackbirds, Agelaius phoeniceus. In neither case did parents respond with consistent increases in feeding, nor did young gain more weight during playbacks. This lack of response is discussed in relation to two other recent studies of blackbirds that did demonstrate increased feeding with playbacks of begging calls. Copyright 1998 The Association for the Study of Animal Behaviour.
雏鸟的乞食行为似乎是向父母传达一窝雏鸟需要多少食物的主要信号。由于竞争导致的夸张行为，不仅可能降低该信息的准确性，而且它还可能随雏鸟的年龄而变化。较年幼的雏鸟相比年长雏鸟在鸣叫频率上的变化可能更大，因为它们对刺激的辨别能力较差。因此，即使是“诚实的”乞食行为，年幼雏鸟发出的信号可能也不如年长雏鸟发出的饥饿信号可靠。我们通过在较年幼（≤5天）和较年长（≥6天）的红翅黑鹂（美洲红翼鸫）巢中播放乞食叫声，来检验这样一个预测：相比于年长雏鸟，父母对年幼雏鸟增加的乞食频率反应会更少。在这两种情况下，父母都没有通过持续增加喂食做出反应，而且在播放叫声期间雏鸟体重也没有增加更多。结合另外两项关于黑鹂的近期研究（这两项研究确实表明播放乞食叫声会增加喂食量）对这种缺乏反应的情况进行了讨论。版权所有1998动物行为研究协会。
