Research On Acoustic Behavior And Influencing Factors Of Rhinopithecus Bieti

Acoustic behavior research has always received extensive attention from researchers.The animal's acoustic behavior research mainly includes three parts: the acoustic characteristics of the sound,the behavioral pattern of the speaker,and the behavioral response of the receiver.The main content of acoustic behavior research is to study the sound communication of animals with the sound signal as the mediation.The Yunnan snub-nosed monkey is the highest existing primate in the world.It lives in arboreal life,and voice communication is the main method of emotional communication and information transmission between its individuals.Due to the small population of Yunnan snub-nosed monkeys,high altitude distribution and limited field observation conditions,there are relatively few studies on the acoustic behavior of Yunnan snub-nosed monkeys.From August 2019 to September 2020,we used the focus animal sampling method,the scanning sampling method and the whole event recording method to study the acoustic behavior and influencing factors of a group of habitual Yunnan snub-nosed monkeys in the Baimaxueshan nature reserve,Yunnan,with a view to exploring Voice communication strategy of Yunnan snub-nosed monkey.During the study period,we observed a total of 74 Yunnan snub-nosed monkeys in 9 one-male units and 1 all-male unit.The main findings are as follows:1.The sound pedigree of the Yunnan snub-nosed monkey was established.Spectral analysis and statistical analysis of the 18 recorded sounds showed that there are differences in the acoustic characteristics and frequency of different sounds.Singlesyllable sounds and sounds composed of single-syllable repetitive arrangements are relatively high in frequency.Comparing the frequency of four different voice types,the results show that the frequency of conflict calls was significantly lower than that of contact calls(t=-4.032,df =863,p<0.01)and friendly calls(t=-8.687,df =1527,p<0.01);the frequency of alarm calls was significantly lower than friendly calls(t=-7.826,df=1168,p<0.01)and contact calls(t=-3.731,df =504,p<0.01).2.A "Dictionary" for the sound interpretation of the Yunnan snub-nosed monkey was established.Using the ASO model,a total of 13 kinds of Yunnan snub-nosed monkey's sound meanings have been established.Comparing the expressions of different meanings when different sounds were emitted,the results show that among all the recorded sounds,12 kinds of sounds can express a specific meaning when they were emitted.This shows that the sounds of Yunnan snub-nosed monkeys contain specific meanings and can be carried out by voices between individuals.Accurate information transmission,effectively avoiding communication restrictions caused by environmental barriers.3.The vocal behavior of Yunnan snub-nosed monkeys was affected by different genders,ages and social units.Comparing the frequency of the four sound types between adult males and adult females,the results show that:(1)the number of sound types of adult males(7)was less than that of adult females(17);(2)The frequency of alarm calls of adult males was significantly lower than that of adult females(t=-11.656,df =1145,p<0.01);(3)The frequency of friendly calls of adult males was significantly higher than that of adult females(t=11.925,df =3067,p<0.01).Comparing the frequency of the four voice types in different age groups,the results show that:(1)The frequency of conflict calls,alarm calls and friendly calls of adults was higher than that of individuals in other age groups;(2)The frequency of contact calls of adults was significantly lower than that of juvenile(t=-5.831,df =1398,p < 0.01)and infant monkeys(t=-5.023,df =1023,p<0.01).Comparing the frequency of the four voice types between one-male unit and allmale unit,the results show:(1)The frequency of conflict calls(t=-3.304,df =6436,p<0.01)and friendly calls(t =-3.254,df =6806,p<0.01)of one-male units was lower than that of all-male unit;(2)The frequency of contact calls of one-male units was higher than that of all-male unit(t=8.191,df =1848,p<0.01).These results show that the acoustic behavior of Yunnan golden snub-nosed monkey was affected by many factors,and the acoustic behavior caused by different factors is different.In this paper,the study of the acoustic behavior of Yunnan snub-nosed monkeys can help researchers reveal the adaptation strategies of primates to the complex ecological environment developed during the long-term evolution of primates from the perspective of sound;in addition,it's useful to provide basic information for species classification and inter-species comparison that combining with other non-human primates related research.