能量分配策略对中华大蟾蜍繁殖成功率的影响

To maximize the fitness under the limited resources, animals should make trade-offs between their investments in survival and reproduction and use optimal energy allocation strategies. How they distribute the resources to survival against breeding? What causes the differences of energy allocation among individuals? What are the impacts of its variation on animals' breeding behaviors, reproductive success, and life history strategies? What factors drive its evolution? These questions are debates for biologists until now. Our previous research showed that breeding behaviors and reproductive success were significantly different among individuals and among breeding seasons in the Asiatic toad (Bufo gargarizans), which might be caused by disparate energy allocation patterns and their dynamics. Using behavior observation techniques and molecular genetic methods, we will study the following issues in this species within the Badagongshan National Nature Reserve, Hunan Province: (1) reproductive threshold and its variation among breeding seasons; (2) the impacts of body condition on their energy investments in breeding and energy allocations; (3) the influences of energy allocation strategy on their breeding behaviors and reproductive success; (4) inter-annual variation and trade-offs of their energy allocation. We will test the related hypotheses to discuss the evolutionary mechanisms of energy allocation and life history strategies of this toad species. The prospective results could promote the development of the related theories and provide scientific evidences to the studies on behavioral ecology, population dynamics, and endangerment process of amphibians and their management and conservation.

动物能获得的能量是有限的，它们需在生存和繁殖间做出权衡，采取最佳的能量分配策略，以获得最大适合度。那么，动物如何合理地分配生存和繁殖所需能量？什么原因导致了能量分配的差异？不同的能量分配策略对繁殖成功率和生活史对策产生怎样的影响？其进化受到什么原因的驱动？这些问题生物学家们一直在争论。我们的前期研究发现：中华大蟾蜍不同个体和不同年份的繁殖行为和繁殖成功率差异显著，这可能受到能量分配策略及其变化的影响。本项目拟采用野外跟踪调查和分子生物学技术，研究湖南八大公山中华大蟾蜍的：（1）繁殖阈值及其年际变化；（2）个体状况对繁殖能量投入和能量分配的影响；（3）能量分配策略对繁殖行为和繁殖成功率的影响；（4）能量分配策略的年际变化和权衡特征，以验证相关假说，探讨中华大蟾蜍能量分配策略和生活史对策进化机制，促进相关理论的发展，为两栖类的行为进化、种群动态和物种濒危机制研究及物种管理、保育提供科学依据。

动物能获得的能量是有限的，它们需在生存和繁殖间做出权衡，采取最佳的能量分配策略，以获得最大适合度。那么，动物如何合理地分配生存和繁殖所需能量？什么原因导致了能量分配的差异？不同的能量分配策略对繁殖成功率和生活史对策产生怎样的影响？其进化受到什么原因的驱动？我们在湖南八大公山建立了野外围栏种群，采用野外跟踪调查和室内实验相结合的方法，研究了中华大蟾蜍能量分配策略的特点、变化、影响因素及其对繁殖成功率的影响，探讨了能量分配策略和生活史对策的进化机制。我们的结果表明：中华大蟾蜍存在繁殖阈值；其能量分配策略是以capital breeding为主，income breeding为辅的混合策略；个体状况对能量分配策略有重要影响，个体状况越好的个体越趋向于capital breeding策略；亲本状况和能量分配策略对繁殖成功率有重要影响，好的亲本和高的繁殖投入可以提高繁殖成功率和繁殖收益；环境条件和种群状况的年际变化可能导致能量分配策略的调整。我们的研究促进了能量分配策略理论的发展，有助于我们更深入的了解两栖类的行为进化、种群动态和物种濒危机制，为两栖类物种的管理、保护和繁育提供重要的理论支持和科学依据。