Figure 2.

A second example of the hyena's giggle call for two experimental animals. A majority of animals used in this study were treated with hormones or gonadectomized as participants in other research projects. In this figure, we show two giggle bouts emitted by two different individuals, Winnie and Kadogo. Winnie is a 14 yr old male treated with anti-androgens in utero. Kadogo is a 6 year old female treated with anti-oestrogens in utero. Hormonal treatment did not have an effect on the acoustical structure of the giggle notes or giggle bouts as assessed by our measures. Winnie is a subordinate animal while Kadogo is a dominant animal. The sounds of the giggle bouts for Winnie are available as Additional Files 5 and 6. The sounds of the giggle bouts for Kadogo are available as Additional Files 7 and 8.