DEB (Ecology): Seed Dispersal by Central American Agoutis - A Mutualism Conditioned by Predators or Food?

种子传播和动物对种子的捕食是影响森林更新和植物多样性进化的关键自然过程。啮齿动物在这方面的作用是有争议的，有人认为啮齿动物对树木有好处，因为它们传播和埋藏种子，对树木有坏处，因为啮齿动物吃种子，或者有条件地互惠互利，取决于当地的食物或捕食者。这种关系仍然不确定，因为很少有研究能够跟踪种子以确定它们的最终命运。这项研究使用运动敏感的无线电发射器来跟踪啮齿动物散布的种子的命运。测试的假设是，啮齿动物是树木的条件互惠者：它们是有效的传播者，只有在种子密度低的地方，啮齿动物死亡的可能性很高，从而留下埋在地下的种子发芽。 影响啮齿动物是种子的传播者还是捕食者的因素对森林管理至关重要，因为啮齿动物仍然倾向于被视为应被杀死的害虫。我们的研究将提供一个框架，了解啮齿动物的作用，以及如何干扰，如破碎和狩猎影响森林再生修改捕食者和啮齿动物的丰度。强调科学有趣的研究与魅力的雨林动物和重要的保护意义将把研究在一个强有力的地位，继续参与教育计划。

Seed dispersal and seed predation by animals are key natural processes that affect forest regeneration and the evolution of plant diversity. The role of rodents in this regard is controversial, having been argued as good for trees because they disperse and bury seeds, bad for trees because rodents eat seeds, or conditionally mutualistic depending on local food or predators. This relationship remains uncertain because few studies have been able to follow seeds to determine their ultimate fate. This study uses motion-sensitive radio transmitters to track the fate of rodent-dispersed seeds. The hypothesis tested is that rodents are conditional mutualists of trees: they are effective dispersers only where seeds are at low density AND rodents have a high likelihood of dying, thus leaving their buried seeds to germinate. The factors affecting whether rodents are dispersers or predators of seeds are of major importance for forest management, where rodents still tend to be viewed as pests that should be killed. Our study will provide a framework for understanding the role of rodents, and of how disturbances such as fragmentation and hunting affect forest regeneration by modifying predator and rodent abundances. Emphasis on scientifically interesting research with charismatic rainforest animals and important conservation implications will put the study in a strong position for continued involvement in educational programs.