Dissertation Research: Effects of Habitat Complexity and Host Dominance on Ant-Parasitoid Interactions

栖息地复杂性和宿主优势对蚂蚁-寄生虫相互作用的影响摘要被捕食或寄生的物种必须平衡逃避捕食者/寄生虫的冲突需求，同时仍然竞争有限的资源。栖息地的物理属性可能会影响物种平衡这些需求的能力，但这种可能性仍然没有探索。这个项目的目标是研究栖息地结构的复杂性如何改变宿主蚂蚁逃离其专业寄生物的能力，同时仍然有效地竞争资源。通过使用不同的蚂蚁社区内的竞争能力的主机，我们还将探讨栖息地的复杂性的主机寄生虫相互作用的后果是否取决于主机的优势水平。实验将在野外使用便携式觅食箱对蚁群进行，以操纵栖息地复杂性（落叶）、竞争和寄生水平。栖息地的复杂性为猎物提供了避难所，这样做，可能会让猎物逃离捕食者/寄生虫，但仍然有效地竞争。然而，干扰事件，如火灾和放牧是常见的美国西南部改变栖息地的复杂性。因此，这种干扰事件有可能通过改变物种间的相互作用来影响自然群落的组成。该项目不仅将在保护美国沿着奇瓦瓦沙漠土地的倡议背景下进行，墨西哥边境，它还将为来自美国和墨西哥机构的生物学学生提供宝贵的培训。

EFFECTS OF HABITAT COMPLEXITY AND HOST DOMINANCE ON ANT-PARASITOID INTERACTIONSPROJECT ABSTRACTSpecies that are subject to predation or parasitism must balance the conflicting demands of escaping from their predators/parasites while still competing for limited resources. Physical attributes of habitats may affect the ability of species to balance these demands, but this possibility remains unexplored. The goal of this project is to examine how habitat structural complexity modifies the ability of host ants to escape from their specialist parasitoids while still competing effectively for resources. By using hosts that differ in their competitive ability within the ant community, we will also explore whether consequences of habitat complexity for host-parasitoid interactions depend on host dominance level. Experiments will be implemented on ant colonies in the field using portable foraging bins to manipulate levels of habitat complexity (leaf litter), competition and parasitism. Habitat complexity provides refuge for prey, and in doing so, may allow prey to escape from predators/parasites but still compete effectively. However, disturbance events such as fire and grazing that are common in the Southwestern United States alter habitat complexity. Such disturbance events therefore have the potential to affect the composition of natural communities by modifying species interactions. Not only will this project be conducted in the context of an initiative to preserve Chihuahuan desert lands along the U.S.-Mexican border, it will also provide valuable training for biology students from both U.S. and Mexican institutions.