Hauber Mark E
Department of Neurobiology and Behavior, Cornell University, USA.
J Comp Psychol. 2003 Mar;117(1):24-30. doi: 10.1037/0735-7036.117.1.24.
The survival of young brood parasites depends critically on their many adaptations to exploit hosts. Parasitic survival is particularly related to competitive superiorty for foster parental care whenever host young are not destroyed in parasitized nests.Brown-headed cowbirds (Molothrus ater) are generalist obligate parasites whose early social environments are unpredictable regarding host species and numbers of nestmates. Young avian brood parasites typically beg more intensively and loudly than foster siblings, but an untested prediction is that young parasites are also more likely to respond by begging to a wider variety of stimulus types. Avian vocalizations were used in a playback experiment to stimulate begging behavior in cowbird hosts. Compared with age-matched cowbird nestlings, hosts begged less frequently to acoustic stimuli, and lower begging responsiveness was irrespective of whether hosts had been reared in parasitized nests.
幼龄巢寄生者的存活严重依赖于它们为利用宿主而产生的多种适应性。每当宿主幼雏在被寄生的巢中未被消灭时，寄生者的存活尤其与争夺养父母照顾的竞争优势相关。褐头牛鹂（Molothrus ater）是专性寄生者，其早期社会环境在宿主种类和巢伴数量方面不可预测。幼龄鸟类巢寄生者通常比寄养同胞更强烈、更大声地乞食，但一个未经检验的预测是，幼龄寄生者也更有可能对更广泛的刺激类型做出乞食反应。在一项回放实验中，使用鸟类叫声来刺激牛鹂宿主的乞食行为。与年龄匹配的牛鹂雏鸟相比，宿主对声学刺激的乞食频率较低，且较低的乞食反应性与宿主是否在被寄生的巢中饲养无关。
