Navigating fragmented tropical landscapes; understanding how forest fragmentation affects bird behaviour

在过去的一个世纪里，大部分热带森林生物群已经从连续不断的未受干扰的森林转变为由退化的原始森林碎片、次生林、牧场和农地组成的复杂的人为修改景观1。相比之下，10%的热带森林生物群受到严格保护区的保护。因此，热带森林生物多样性的长期养护越来越依赖于支离破碎的人为改变的地貌是否能够支持森林物种的存活种群2，4以及景观动态在多大程度上改变物种的行为和相互作用5，6以前对支离破碎的森林地貌中的鸟类的研究描述了物种的存在和丰富，但未能解释为什么我们看到某些物种以碎片形式存在，而另一些物种只在连续的森林中发现。答案可能在于动物如何利用它们的空间环境和在森林碎片之间移动的能力来满足饮食、栖息和繁殖需求，同时避免捕食8。目前，我们对鸟类如何在未受干扰的栖息地分散知之甚少，更不用说如何随着栖息地的碎片化而改变运动模式了。我们预测物种生活史和形态特征将与景观组成相互作用，以确定森林碎片之间的扩散。例如，扩散距离较大的动物物种可能比栖息地较小、分散较差的物种受碎片化影响较小。图1：Cerro Cama景观中的森林碎片。在这个项目中，我们将在巴拿马中部特色良好的风景中工作，在那里我们将使用最先进的无线电跟踪设备来标记鸟类，这些设备能够记录它们在森林碎片内和森林碎片之间的移动。这些设备代表了最新的动物运动监测技术，将为我们提供有关单个鸟类运动的前所未有的详细信息。我们将把这些新颖的数据与现有的景观知识以及鸟类的功能和生活史特征数据结合起来：1.描述鸟类(从物种的子集)如何从森林景观转变为碎片化的景观。了解景观结构和物种迁徙是如何影响移动模式的。量化人类改造的鸟类景观的功能连通性，并确定这如何塑造单个森林碎片的物种组成。

Over the last century much of the tropical forest biome has been converted from continuous tracts of undisturbed forest to complex human-modified landscapes composed of degraded primary forest fragments, secondary forest, pasture and agricultural land1,2. In contrast, <10% of the tropical forest biome is protected within strict reserves3. Consequently, the long-term conservation of tropical forest biodiversity is increasingly dependent on whether fragmented, human-modified landscapes can support viable populations of forest species2,4 and the extent to which landscape dynamics alter species behaviour and interactions5,6. Previous studies of birds in fragmented forest landscapes describe the presence and abundance of species but fail to explain why we see certain species persisting in fragments while others are only found in continuous forest7. The answer likely lies in how animals use their spatial environment and their capacity to move among forest fragments to meet dietary, roosting and reproduction needs, while avoiding predation8. Currently, we know little about how birds disperse in undisturbed habitats let alone how movement patterns shift with habitat fragmentation. We predict that species life-history and morphological traits will interact with landscape composition to determine dispersal among forest fragments9. For example, animal species with large dispersal distances may be less affected by fragmentation than poorly dispersed species with small home ranges. Fig1: Forest fragments in the Cerro Cama landscape.In this project we will work in well-characterised landscapes in central Panama, where we will tag birds with state-of-the-art radio tracking devices capable of recording their movements within and between forest fragments. These devices represent the latest in animal movement monitoring technology and will provide us with unprecedented detail on individual bird movements. We will integrate these novel data with existing knowledge of the landscape, and bird functional and life-history trait data to:1. Describe how the movement patterns of birds (from a subset of species) shift from forested tofragmented landscapes.2. Understand how movement patterns are mediated by landscape structure and species traits.3. Quantify the functional connectivity of human-modified landscapes for birds, and identify how this shapes species composition of individual forest fragments.