The Study On Population Density, Habitat Selection And Age Structure Of Eremias Multiocellata In The Northern Mountains Of Lanzhou City

Population characteristics and habitat selection are all significant issues in the study of population ecology. The population and habitat selection of Multiocellated racerunner(Eremias multiocellata) that distributed in Northern mountains of Anning, Gansu province Lanzhou city were investigated during the period of 2014. In the investigation, we have randomly captured 63 tails of Multiocellated racerunner and we have measured their body length and analysed their bone age. The main results are as follows:(1) During April to June of 2014, we choose 9 at morning until 13 in the afternoon of sunny weather to investigate the population of lizards. Through the setting study places to compile statistics, the number of lizards in every study places is different and there are 21 E. multiocellata in the Platycladus orientali—Caragana Korshinskii community, 5 E. multiocellata in the Caragana Korshinskii—Setaria viridis community. The most number of E. argus is distributed in the Caragana Korshinskii—Artemisia capillaries community, but no E. argus is distributed in the Setaria viridis community, Tamarix ramosissima and Caragana Korshinskii—Setaria viridis. Totally, there are 94 tails Eremias multiocellata recorded in the 9 study places and averagely about 10.44 individuals within every quadrat, and the distribution area is about 0.0116/m2 and 34 tails E. argus are investigated, about 3.78 individuals within every quadrat, and the distribution area of E. argus is about 0.0042/m2.(2) In the habitat selection survey, we set up 23 habitat quadrats and 25 countral quadrats to discuss the habitat selection of the E. multiocellata and used non parametric test for two independent samples to analysis the ecological factors between selected quadrats and control quadrats. The result shows that there is no significant difference among the shrub species, shrub coverages, shrub height, grass species and grass coverages. But the proportion of bare area between habitat quadrats and countral quadrats is significant. It is indicated that the proportion of bare area affects the habitat selection behaviour of E. multiocellata. Principal component analysis of the habitat ecological factor shows that the first principal component is positive correlation among herbaceous species and cover degree but is negative correlation between the proportion of bare land.The second principal component is positive correlation among shrub cover and vegetation cover and the third principal components is positive correlation among shrub species. Hence the food factor, safety factor, sun factor and so on influence the process of habitat selection for lizards.(3) The morphological index clustering analysis shows that the type traits are variables in sizes. The similarities among head length, head width, length of hind leg, shank length, snout length, length of foreleg, space and interorbital length is much high. The similarities among weight, snout-vent length and space between axilla and groin is much high. But the similarities among tail length, eye diameter and length have little similarity. They also have little similarity with the other 11 indicators above. Through the head body length of the frequency distribution chart, the E. multiocellata can be divided into 2 age groups: 37.5mm~50mm is the first age group, 52.5~67.5mm is the second age group. The skeletochronology of the age suggests that there are 10 tails belonging to the one age group(SVL=42.63±2.49m),17 tails are belonging to the 2 year old group(SVL=52.93±3.37mm), 28 tails are belonging to the 3 year old group(SVL=59.12±1.03mm)and only 7 tails are belonging to the 4 year old group(SVL=63.09±1.01mm).(4) Remove the individuals head body length below 50 mm the following, whose the sexual dimorphism index of E. multiocellata is about-0.0019. And two sexual sample mean difference test show that E. multiocellata individual size had no significant difference(P ﹦ 0.903 > 0.05). According to Powell’s classification, E. multiocellata belong to third types, that is to say, the snout-vent length of individual have no obvious size difference between two maturity sexual.