Study On Mating System And Home Range Of Wild Tree Shrews

The study on mating system and home range of wild animals is the most significant field of behavioral ecology because it provides us a detailed understanding of the complex relationship between behavior,life history,space utilization and reproductive strategies and habitat environment of a species.The tree shrews(Tupaia belangeri)is a small,squirrel-like mammal,it's a unique species of the Scandentia in China,and which is widely distributed throughout Guangxi and Hainan island as well as southwest of China including Yunnan,Guizhou and Sichuan.In the past,much of research mainly focused on laboratory,it makes the field ecological data about tree shrews relatively lacking.The research on the kinship identification,community behavior and social structure of the tree shrews in the wild can reflect the mating relationship and mating pattern of this species,and reveal the adaptation mechanism of wild populations to complex and variable environmental conditions.In addition,Tupaia belangeri have been widely used in biomedical research fields,The scale of domestication and breeding is expanding in China,The study of wild ecological behaviors of tree shrews included mating system can also provide a reference for breeding and also improve the survival rate.The animal samples were collected in the wild at the Haikou Forest Farm in Xishan District,Kunming City from March to May 2018.Highly polymorphic microsatellite DNA was selected as a marker,and all individuals were paternity identification,and mapping parenthood.Finally,we analyze the mating relationship between males and females.At the same time,to examine the potential for sperm selection in tree shrews and primates,than collated 68 primate species data on testis size and body size from earlier reviews,we used analysis of covariance(ANCOVA)with log body size as the covariate to examine whether log testis size differs between mating systems.In addition,the radio collar is used to study the home range,daily activity distance and space utilization of this species.The main results and conclusions of this thesis consists of five parts:1.A total of 151 animals were collected,involving 68 males and 83 females,the results showed that:the genetic parameters showed that only one locus(TBC1)deviated from Hardy-Weinberg equilibrium,the number of alleles was ranged from 2to 9.The average observed heterozygosity(Ho)was between 0.2476 and 0.8367,with an average of 0.5958.The expected heterozygosity(He)ranged from 0.2789 to0.7773 with an average of 0.5998.The polymorphism information content(PIC)ranged from 0.2469 to 0.8771 with an average of 0.5298,and the overall genetic diversity was higher.Based on the above data,the Tupaia belangeri in Haikou Forest Farm has a high level of genetic diversity.2.The identification of 7 microsatellite loci were analyzed in the Cervus3.0,under the confidence of 95%and 80%,the cumulative probability of paternity exclusion rate was 99.96%.A total of 48 individuals were identified,involving 15parent-female-child relationships,3 parent-child and 5 parent-child.Kingroup v2 was used to identify the kinship coefficient between individuals,and it was also shown that 7 offspring(30.43%)were sired by males that were not the presumed partner of the mother,the mating system of T.belangeri belongs to monogamous.Molecular evidence reveals that the marriage system of this species is more complex and diverse than previously recognized.3.Relative testis size of T.belangeri was similar to the primate species with uni-male mating systems but smaller than the primates with multi-male and polygamy mating systems.I also found that the evolution of multi-male mating systems was significantly associated with the evolution of larger testis size.The primate testes are significantly more related to the evolution of the evolutionary system and the mating system of the primate monkeys.And with the increase of number samples,the mating system of T.belangeri is more similar strepsirrhine primates.4.In addition,in order to understand the ecological habits of tree shrews in the wild,we used the traditional marker recapture method to estimate the population size in the Haikou Forest Farm,the density was 3.4 per hectare,the higher population density is actively related to the natural conditions such as diverse vegetation,less human disturbance,and abundant fruit resources in the region.The home range of 9individuals were studied by radio-telemetry.We used the 95%minimum convex polygon method(MCP)to estimate the home range.The results showed that the maximum distance of the adult male and female was 353.85±16 m and 285.23±18m per day respectively,the sizes of male(n=5)home range was 11583.86±32 m~2,while the sizes of female(n=4)home range was 9151.43±45 m~2.This is the first evidence using radio-collar to study the home range from wild Tupaia belangeri,we hope its can offer some substantial help in the field ecology research of Chinese tree shrews.In summary,the DNA molecular evidence reveals that the mating system of T.belangeri blongs to monogamous,but some offspring revealed multiple extrapair paternity.In addition,analysis of phylogenetically independent contrasts of testis size(controlled for body mass)and behavioral mating system indicated that the evolution of multimale mating systems in primates is significantly associated with the evolution of larger relative testis size as well as indicating that sperm competition is not an important evolutionary force in T.belangeri.During the reproductive season,there is a little overlap of home range between the male and female,lead to ineffectiveness of mate guarding and monopolizing females,and the chances of females seeking extramarital spouses increase finally exhibited one of the highest rates of EPP recorded..