The Courtshipand Mating Behavior Of Red Knobby Newts,Tylototriton Shanjing, In Ailao Mountains, Xinping, Yunnan

Different from anuran which is external fertilization, the most of the caudate amphibian species are internal fertilization except for few groups of them. During the reproduction period,there are complex courtship and mating behaviors. Whether or not they succeed in courtship and mating will determines an individual’s breeding success. This will affect not only the individual’s fitness, but also the population dynamics. The study of courtship and mating behavior of the caudate amphibians will have an important significance in the protection of amphibians.Red Knobby Newt(Tylototriton shanjing) is a typical species of caudate amphibians which distributed in montane environment of Yunnan province, which was belongs to national grade Ⅱkey protected wild animals. Although there were some researches on the morphology,geographical distribution, the taxonomic status, biological characteristics, breeding habits,spawning behavior and early embryonic development of the species, the courtship and mating behavior of the species was till unknown.In this thesis, a survey was conducted on the courtship and mating behaviors of Red Knobby Newt at Ailao mountain, Xinping, Yunnan in the April to June 2013 and from May to June 2014.During the study, I observed the courtship and mating activities of the newts, investigated the environmental variables which affect the courtship and mating behavior of the newt, measured the morphological traits of the courting individual, and observed and recorded the courtship and mating behavior process of the newts. In order to understand the general rule of the courtship and mating behavior of the newt, time of courtship and mating, daily activities rhythm, distribution,sex ratio of newt, courting habitat utilization, and impacts of environmental and climate variables on the courtship and mating behavior were analyzed, the relationship between the morphological traits of courting individuals and mating success was explored, and the courtship and mating mode the this species in terrestrial environment was recognized.The results showed that the courtship and mating time of this newt was mainly concentrated on middle May to late June every breeding season in the study site. The number of courting individuals peaked at the early period of the breeding season, and decreased gradually. In the entire courtship and mating process, the number of male newts was significantly greater than the females’. The newts mainly chose the rich vegetation, hidden and humid, and quiet ditches and other places as the courtship and mating sites. The courtship and mating activity of the newt occurred mainly in the morning. Rainfall and air relative humidity were the important environmental factors which affect the courtship and mating behavior of the newts.Study on the morphological traits of the courting newts showed that there were sexual size dimorphism between the courting male and female. Female newts were larger than males in mostmorphological variables. Analysis of morphological traits comparison for different individuals in different mating success stages showed that the male in success for mating was smaller, but larger in female. The ratio of male and female size was greater in succeeded courtship and mating. This indicated the smaller males and the larger females were more likely to mate successfully.The course of courtship and mating behavior of the Red Knobby Newts proceeded in sequence, and was composed of four stages, include orientation, static display, lure display and spermatophore transfer. Individuals of the courting newts in any stage might come back to the first stage because of internal or external intervention.The courtship and mating behavior of males was complex, 10 types were recognized including alert, pursuit, interception, creep, sniff,nudge, lure, tail-fanning, lateral walk and spernatophore deposition, but females’ monotonic,only 4 types including move away, stationary, follow and retrieval of sperm. The males’ courtship behaviors were complicated than the females’ behaviors. Males always had the initiative during the process of courtship and mating. Visual recognition may be the main cognition style between the two sexes. No amplexus were observed in land courtship and mating of the newts. The tail movements were relatively monotonous. Those behaviors changes in courtship and mating might be the adaptations to land environments.