A Comparison Of Acoustic Structure Of Vocalization In Different Habitat Frog Species In The Mt.diaoluo National Nature Reserve

Vocal communication is one of the most important methods of communication in anurans.It plays an important role in reproduction.The acoustic characteristics of anurans are affected by individual characteristics,including heredity,hormone levels,and body size.Moreover,it is limited by the environmental factors,such as temperature,relative humidity,and geographic location.In previous studies,longer duration and lower frequency of sound were found in birds from areas with dense vegetation.The dominant frequency and amplitude of acoustic signals might change to improve the efficiency of transmission,in anuran species that live near torrents.In present study,we collected and analyzed 21 species in Mt.Diaoluo National Nature Reserve for comparing the effect of different habitats factors on acoustic characteristics.Nine arboreal anurans were included in the present study.Chirixalus vittatus was the only species with a monosyllabic call,Chirixalus doriac and Philautus hainanus had multisyllabic calls,Liuixalus ocellatus,Rhacophorus rhodopus,and Rhacophorus dennysi had both monosyllabic and multisyllabic calls,and Aquixalus odontotarsus,Polypedates megacephalus,and Polypedates mutus had various types of calls.We analyzed the relationship between size and acoustic characteristics.The dominant frequency was negatively correlated with head length,body mass,head width,and snout-vent length in most species.The dominant frequency of Rhacophoridae decreased with an increase in snout-vent length,and the acoustic characteristics varied with body size and genus.We collected and analyzed seven terrestrial species.To the best of our knowledge,the first data ever on vocal characteristics of two species,Microhyla butleri and Leptobrachium hainanensis,have been studied here.The advertisement calls of one male M.butleri were successfully recorded.There are two basic call-types—monosyllabic calls(note duration:200.76 ± 7.85 ms;fundamental frequency: 580.58 ± 56.31 Hz;dominant frequency: 1401.52± 20.51 Hz)and multisyllabic call(note duration: 175.23 ± 9.50 ms;fundamental frequency:596.13 ± 54.76 Hz;dominant frequency: 1403.59 ± 15.05 Hz).The advertisement calls of 10 male L.hainanensis were successfully recorded.They revealed two basic call-types—monosyllabic call(note duration: 94.69 ± 9.85 ms;fundamental frequency:265.04 ± 108.90 Hz;dominant frequency: 1057.94 ± 161.15 Hz)and multisyllabic call(note duration: 9.80 ± 0.81 ms;fundamental frequency: 748.12 ± 13.27 Hz;dominant frequency:802.48 ± 128.66 Hz).Parapelophryne scalpta and M.heymonsi had one call type,whereas M.pulchra,Fejervarya multistriata,and Duttaphrynus melanostictus had two call types.Theadvertisement calls of terrestrial anurans were simpler than that of arboreal anurans.In the present study,we did not find any relationship between body size and acoustic characteristics of species belonging to the family Microhylidae.We recorded the calls of five species from aquatic habitats.Multisyllabic calls were comprised 56.8 ± 12.5 notes in Amolops torrentis.Two basic types of calls,monosyllabic and multisyllabic calls,were recorded in Limnonectes fragilis and Buergeria oxycephala.Three types of calls of Hylarana spinulosa,with two different monosyllabic calls were recorded.Odorrana graminea could emit nine types of calls with frequency modulation.The dominant frequency of calls by O.graminea was about 3–5 kHz,with the highest frequency of approximately 20 kHz.Several differences in call characteristics among populations from Mt.Diaoluo and Mt.Huangshan were found.The dominant frequency of B.oxycephala was lesser than that of L.fragile,although their sizes were similar.The dominant frequency of species of Ranidae from aquatic habitats was negatively correlated with snout-vent length(Pearson's correlation analysis,P < 0.05).The dominant frequency of turbulence was higher near torrents than near still water(t-test,P < 0.05).The acoustic characteristics of anurans from aquatic habitats were affected by differences in habitat characteristics,taxonomic families,and body size.