Fichtel Claudia
Department of Behavioral Ecology and Sociobiology, German Primate Center, Göttingen, Germany.
Am J Primatol. 2008 Feb;70(2):127-35. doi: 10.1002/ajp.20464.
The production of vocalizations in nonhuman primates is predominantly innate, whereas learning influences the usage and comprehension of vocalizations. In this study, I examined the development of alarm call recognition in free-ranging infant Verreaux's sifakas. Specifically, I investigated their ability to recognize conspecific alarm calls as well as those of sympatric redfronted lemurs (Eulemur fulvus rufus) in Kirindy forest, western Madagascar. Both species have functionally referential alarm calls for aerial predators and give general alarm calls for both aerial and general predators and also other kinds of threats, such as intergroup encounters with conspecifics. I conducted playback experiments with members of two birth cohorts (nine and ten individuals) to determine the age at which infant Verreaux's sifakas discriminate between conspecific alarm calls, heterospecific alarm calls, and non-alarm vocalizations (parrot song). Most 3-4 months old infants fled toward adults after hearing any playback stimuli, whereas 4-5-month-old infants did so only after presentation of alarm calls. Moreover, all infants of these age classes showed a longer latency to flee after the parrot song indicating their emerging ability to discriminate between alarm calls and non-alarm stimuli. At an age of about 6 months, infants switched from fleeing toward adults to performing adult-like escape responses after presentation of conspecific and heterospecific alarm calls. Thus, the ability to discriminate between alarm from non-alarm stimuli precedes the appearance of adult-like responses. The transition to adult-like escape behavior was coincident with the physical independence of infants from their mothers.
非人类灵长类动物发声的产生主要是先天的，而学习则影响发声的使用和理解。在本研究中，我考察了自由放养的婴儿维氏冕狐猴警报叫声识别能力的发展。具体而言，我研究了它们识别同种警报叫声以及马达加斯加西部基林迪森林中同域分布的红额狐猴（Eulemur fulvus rufus）警报叫声的能力。这两个物种都有针对空中捕食者的功能性指示警报叫声，以及针对空中和地面捕食者以及其他种类威胁（如同种群体间遭遇）的一般警报叫声。我对两个出生队列的成员（九个和十个个体）进行了回放实验，以确定婴儿维氏冕狐猴能够区分同种警报叫声、异种警报叫声和非警报叫声（鹦鹉叫声）的年龄。大多数3 - 4个月大的婴儿在听到任何回放刺激后都会跑向成年个体，而4 - 5个月大的婴儿只有在听到警报叫声后才会这样做。此外，这些年龄段的所有婴儿在听到鹦鹉叫声后逃跑的潜伏期更长，这表明他们开始有能力区分警报叫声和非警报刺激。在大约6个月大时，婴儿在听到同种和异种警报叫声后，从跑向成年个体转变为做出类似成年个体的逃避反应。因此，区分警报和非警报刺激的能力先于类似成年个体反应的出现。向类似成年个体逃避行为的转变与婴儿从母亲身边的身体独立同时发生。
