Study On Chemical Communication By Giant Pandas(Ailuropoda Melanoleuca)

As a flagship species of biodiversity conservation worldwide,the giant panda(Ailuropoda melanoleuca)is a solitary species.Currently,this species has been confined to isolated patches of mountainous habitats in southwestern China due to human activities and climate change.Conspecific communication among giant pandas depends heavily on chemical signals.To better promote the survival and reproduction of this species,we conducted a long-term study by investigating and monitoring,and analyzed the characteristics of behavioral ecology and consist of chemical signal by giant panda.We expect a systematic understanding of chemical communication,and wish to make more scientific suggestions based on our results.This study obtained a novel dataset by integrating transect surveys,infrared camera traps and gas chromatography-mass spectrometry.We systematically analyzed the characteristics of chemical communication by giant panda in Wolong Nature Reserve from selection of scent mark tree,behavioral characteristics oof scent communication and compounds composition of scent signal,the results shown that:(1)The marked trees are more commonly located on ridges,where the main forest type was coniferous forests(54.8%),canopy coverage of trees was 0.45±0.19,the dominant tree species was Faxon Fir(Abies faxoniana Rehd.et Wils.)(49.9%),the average height of shrub was 3.2 m ± 0.6 m and coverage was 38% ± 14%.Giant pandas preferred to mark the trees with greater than 50 cm DBH.Giant pandas also more commonly chose the trees with heights of more than 5 m as scent marking trees.Roughness,aspect,average height of trees in environment,slope,tree species,DBH of scent mark tree and elevation were key factors that affect scent marking by giant panda.(2)The monitoring results from infrared cameras shown that leg cock(42%)and quadrupedal postures(40%)were used more often than the other two postures of handstand and squat.The time spent scent marking and investigating usually take less than 30 seconds.With respect to behavioral rhythm,there were three peaks throughout the year(i.e.,around October,December,and March),most frequent scent communication behaviors occurred during 18:00-20:00,which present seasonal changes.Scent marking activity in spring initially increased from 5:00 in the morning,which is earlier than the other two seasons.Springtime scent marking had three apparent peaks(5:00 to 8:00,11:00 to 14:00,and 17:00 to 19:00).The peak of scent marking in summer-autumn was mainly in the afternoon(15:00 to16:00)and evening(18:00 to 20:00).The summer-autumn evening peak was the highest peak across the three seasons.In the winter,frequency of scent marking increased from 7:00,then reached the highest peak around 18:00.The use frequency of scent marker also varies with breeding season and non-breeding season,the frequency of use of AGS signals was significantly greater than urine markings only for the mating season(P=0.018),but not other times of year(P=0.396).(3)91 compounds were obtained by analyzing scent marker of giant panda using GC-MS technology,including 76 volatile compounds and 15 Semi-volatile compounds.There were 17 alcohols compounds,15 carboxylic acid compounds,10 olefin compounds,9 ketone compounds,7 heterocyclic compounds,6 cyclic compounds,5 aldehyde compounds,3 Amine compounds,2 ether compounds,1aromatic compound and 1 ester compound.Octanal,2,2,4-Trimethyl-1,3-pentanediol diisobutyrate,Hexanal and Nonanal were more common in all samples,and found in other study,they were potential important source of chemical pheromones in the giant panda.