Holman S D, Seale W T
MRC Neuroendocrine Development and Behaviour Group, Institute of Animal Physiology and Genetics Research, Babraham, Cambridge, UK.
Dev Psychobiol. 1991 Mar;24(2):103-15. doi: 10.1002/dev.420240204.
Sexual differentiation of emission rates (Experiment 1) and physical structure of ultrasonic vocalizations (Experiment 2) were investigated in Mongolian gerbils between 17 and 85 days of age. Animals from different litters were allowed to interact in iso- and heterosexual pairs. Vocalization rates increased in all groups, reaching a plateau at approximately day 56. Female pups had significantly higher rates of all vocalizations than male pairs before the plateau stage. Five stereotypic categories of physical structure were easily distinguished and confirmed by sound spectrographic analysis. Only mid-range frequencies of vocalizations appeared to decline throughout the juveniles' lives: this change may communicate the animal's age. Two male and one female categories were sexually dimorphic and similar in structure to those made during courtship interactions. Rates of male-type vocalizations appear to increase as testicular androgens start rising.
研究了17至85日龄蒙古沙鼠发声率的性别分化（实验1）和超声波发声的物理结构（实验2）。来自不同窝的动物以同性和异性对的形式进行互动。所有组的发声率均有所增加，在大约第56天达到平稳状态。在平稳阶段之前，雌性幼崽的所有发声率均显著高于雄性对。通过声谱分析很容易区分并确认了五种物理结构的刻板类别。在整个幼年期，只有发声的中频似乎在下降：这种变化可能传达了动物的年龄。有两种雄性类别和一种雌性类别具有性别二态性，其结构与求偶互动期间发出的声音相似。随着睾丸雄激素开始上升，雄性类型发声的比率似乎也在增加。
