References Beecher, M. D. (2021). Why are no animal communication systems simple languages ? Frontiers in Psychology , 701. Burling, R., Armstrong, D. F., Blount, B. G., Callaghan, C. A., Foster, M. L., King, B. J., ... & Wynn, T. (1993). Primate calls, human language, and nonverbal communication [and comments and reply]. Current Anthropology , 34 (1), 25- 53. Čadková , L. (2015). Do they speak language?. Biosemiotics, 8(1), 9-27. Clutton -Brock, T. H., and Albon , S. D. (1979). The roaring of red deer and the evolution of onest advertisement . Behaviour 69 , 145–170. doi : 10.1163/156853979X00449 Hockett, C. F., & Hockett, C. D. (1960). The origin of speech. Scientific American , 203 (3), 88-97. Rachel Iileka Petrina Hamulunga