The Study On The Mating System Of Himalayana Marmot And Potential Ecological Factors In Zoige Wetland

The Himalayan marmot(Marmota himalayana)is a large burrowing rodent that lives a family life.At the same time,as the main carrying species of plague,the detection of population dynamics is very important.Mating system can provide help to explore the dynamic changes of population,understand its life history,reproductive strategies,group selection and so on.From April to September in 2019-2020,we selected two populations of Himalayan marmot in Duoma Village,Ruoergai County,Sichuan Province.We used two methods of trap cage and ground net(laying fishing net on the ground).Capturing complete individuals from 9 families in front of the village(high disturbance population,HDP),and complete pups from 8 families behind the village(low disturbance population,LDP).The study hypothesized that the marmots' mating system is monogamous,which fits with the Habitat Variation-Mating System model,and that human interference increases their extramarital reproductive behavior.The parents were identified by microsatellite loci to establish a family,determine the mating system of Himalayan marmot,and quantify the two ecological factors of food resources and burrow resources.The results are as follows:1)Twenty pairs of microsatellite primers(19 pairs of genetic identification primers and 1 pair of sex identification primers)were screened,and a total of 111 alleles were detected in 77 individuals of HDP population by 19 pairs of primers.The minimum number of alleles was 4 and the maximum number of alleles was 12.A total of 120 alleles were detected in 37 individuals of LDP population.The minimum number of alleles was 4 and the maximum number of alleles was 12.2)According to the results of analysis of molecular variance(AMOVA),the genetic variation of HDP population was mainly from within the population,and the inter-population genetic variation accounted for 33%of the total variation,while the intra-population genetic variation accounted for 67%of the total variation.The genetic variation of individuals in LDP population mainly came from inter-population,among which the inter-population genetic variation accounted for 52%of the total variation,and the intra-population genetic variation accounted for 48%.3)All adult females and males available for reproduction were used as candidate mothers and candidate fathers for parental identification of each individual in HDP population.Among the 77 individuals,there were 31 candidate mother and 28 candidate father.When the confidence level was 95%,the identification rate of true mother and true father was 25.97%and 37.66%,respectively.The parental identification rate was 11.69%.The family mating system of Himalayan marmot is relatively complex.In HDP region,most families are a complete breeding pair,and no multiple independent breeding pairs are found in the same family,that is,the mating system is mainly monogamy,polygyny,extramarital breeding,and inbreeding phenomenon exists.Compared with the HDP area,the extramarital infidelity was not obvious in the LDP area.4)The biomass abundance of HDP family grassland was 100.5±5.083 g/m2,and that of LDP family grassland was 111.8± 5.702 g/m2.There was no significant difference between HDP and LDP family grassland.One-way analysis of variance(ANOVA)showed that the biomass distribution of grassland was uniform.The abundance of food resources and the even distribution of food reduced the pressure for sexual selection between the sexes,leading to monogamy in Himalayan marmot.5)The average number of burrows in HDP family was 19.76±1.393,and that in LDP family was 13.39±0.9545.Compared with LDP family,the average number of burrows in HDP family was significantly increased.An increase in the average number of burrows in a household facilitates extramarital infidelity(providing more hidden places);the temporary burrow range of HDP and LDP family was 3454±247.2 m2 and 2198±285.5 m2,respectively.Compared with LDP,the temporary burrow range of HDP family was significantly increased.The distance between breeding holes in HDP and LDP families was 118.3±5.156 m and 143.7±7.037 m,respectively.Compared with LDP,the distance between breeding holes in HDP families was significantly reduced.An increase in the range of temporary family burrows and a decrease in the distance between breeding burrows would change the frequency of encounters among marmots,increasing the likelihood of infidelities.Finally,we draw the following conclusions about the mating system of Himalayan marmot in the study area:1.Himalayan marmot mating system for the basic monogamy system.2.The mating system of Himalayan marmot conforms to the habitat variation-mating system model.3.Human disturbance did not affect the abundance and distribution of grassland biomass,but the changes of burrow resource characteristics caused by human disturbance affected the mating system of Himalayan marmot.