Dissertation Research: Development of Alarm-Call Response Behavior

[3111508]福尔摩斯警报呼叫是捕食者发出的声音，可以提醒物种的其他成员即将发生危险。警报呼叫只有在对捕食者的类型做出适当的反应时才具有功能价值。吉尔·m·马特奥（Jill M. Mateo）的博士论文研究旨在确定年幼的贝尔丁地松鼠何时以及如何对警报信号做出反应，因为她的试验数据显示，当年幼的地松鼠刚从它们出生的洞穴中钻出来时，警报信号的反应还没有完全形成。马特奥女士将测试关于听觉经验和社会环境对警报呼叫反应发展的相对重要性的三个预测：(1)断奶前母亲发声的经验有助于幼儿在断奶后区分警报呼叫；(2)断奶后，通过观察成人的报警反应，可以促进幼儿报警反应的发展；(3)在有其他响应个体在场的情况下，如果幼儿反复听到报警反应，其报警反应的质量会迅速提高。这些预测将通过回放警报的录音，记录未断奶幼犬的心脏反应，以及饲养在半自然环境或生活在野外的幼犬的行为反应来验证。结果将有助于解释社会影响如何促进关键生存技能的发展，并将推进我们对行为如何通过生物体与其一生中遇到的一系列环境之间紧密交织的相互作用而发展的理解。

9311508 Holmes Alarm calls are vocalizations elicited by predators that can alert other members of the species to impending danger. Alarm calls have functional value only if they are responded to appropriately for the type of predator. Ms. Jill M. Mateo's doctoral-dissertation research seeks to determine when and how responses to alarm calls develop in young Belding's ground squirrels, as her pilot data show that alarm-call responses are not fully developed when young ground squirrels first emerge from the burrow where they were born. Ms. Mateo will test three predictions about the relative importance of auditory experience and social context for the development of alarm-call responses: (1) experience with the mother's vocalizations before weaning helps the young to discriminate alarm calls after weaning; (2) development of alarm-call responses after weaning is socially facilitated by observing adult alarm-call responses, and (3) the quality of juvenile alarm-call responses improves rapidly if they repeatedly hear alarm calls in the presence of other responding individuals. These predictions will be tested by playing back tape-recordings of alarm calls and recording the cardiac responses of unweaned pups and the behavioral responses of juveniles housed in a semi-natural environment or living in the field. Results will help explain how social influences contribute to the development of a critical survival skill, and will advance our understanding of how behavior develops through tightly-woven interactions between the organism and the series of environments it encounters throughout its life.