Life History And Behavioral Response Strategies Of North Grass Lizards(Takydromus Septentrionalis)to Climate Warming

Climate warming caused by human activities has become a major global issue,which has a huge influence on animal groups all over the world.Life history response is the key to understanding how animals respond to climate warming.The behavior and physiological response of animals to climate warming will eventually be reflected through life history response.Furthermore,life history response determines the basis of animal population response to climate warming.The northern grass lizard(Takydromus septentrionalis)is a short generation small lizard widely distributed in China.As a typical exothermic reptile,its physiological function is directly controlled by environmental temperature.Therefore,studying the physiological mechanism of animal life history characteristics in response to climate warming is an ideal material.Here,all individuals were divided into heating group and normal temperature group,and they were raised in semi natural enclosure.In heating group,the top of enclosure was covered with half transparent plastic film to increase temperature.In normal temperature group,the top of enclosure was covered with half sunshade net to maintain normal temperature,and in enclosure,grass was allowed to grow naturally to simulate the natural environment.The effects of climate warming on Takydromus septentrionalis and its physiological mechanism adapt to climate warming were evaluated by measuring its behavior heat regulation mode and rhythm(time of coming out to bask in the back,mode and frequency of basking in the back),reproductive survival(body length,body weight,frequency of reproduction,number of eggs in the nest,weight of eggs in the nest),hatching cycle and hatching success rate of offspring.Meanwhile,some individuals of different treatments were randomly selected,and the potential impact of climate warming on animal intestinal microbiota was assessed by measuring the intestinal microbiota diversity.The main results are as following:1.There was no significant difference in body length and body weight among different treatment groups,however the survival rate at the end of breeding season in the heating treatment group was significantly lower than that in the normal temperature treatment group.The reproductive frequency in the normal temperature treatment group was significantly lower than that in the heating treatment group,but the number of clutch size in the heating treatment group was less than that in the normal temperature treatment group.The mean egg mass in the the heating group was significantly higher than that in the the normal temperature group.The hatching time and hatching rate of eggs in the normal temperature treatment group were significantly higher than that in the heating treatment group,but the hatching rate of eggs in the normal temperature treatment group was significantly lower than that in the heating treatment group.2.From three aspects of time,space and behavior,warming had significant effects on the thermoregulatory behavior of Takydromus septentrionalis.Compared with the normal temperature treatment,the warming treatment,there was higher activity frequency in the morning and dusk,and higher activity frequency in the filter and noshade place in the semi natural fence.The frequency of resting thermoregulatory behavior of the two groups was higher than that of moving thermoregulatory behavior,but the frequency of moving thermoregulatory behavior of the warming treatment was higher.3.Through the classification and identification of the microbial community in the intestinal contents of the lizard,19 phyla and 100 genera of different microbial species were detected.Although there were some differences in the major species of intestinal microflora between the two treatment groups,the results indicated that there were no significant differences in the richness and diversity of intestinal microflora between the two treatment groups.4.In this study the physiological mechanism of life history characteristics in response to climate warming was quantified,and it was changed under warming conditions.The results showed that the temperature would affect the survival of the lizard,and would change the reproductive characteristics of the lizard.Moreover,thermoregulatory behavior of the lizard in response to climate warming would also change,but the structure and abundance of intestinal microorganisms of the lizard did not change significantly.It can be effectively confirmed that climate warming is an important factor affecting the life history characteristics of Takydromus septentrionalis.