Climate change poses a major risk to biodiversity and understanding and predicting the resilience of ecological communities is a fundamental question, critical to guiding policy. But how robust are ecological communities to a changing climate? Are ecological communities like crystals, initially resisting change until a threshold of pressure is exceeded and they finally shatter? Or are ecological communities more like plasticene, locally deformed by the slightest pressure, but able to reform and maintain their global ecological function? Key to answering this question is understanding the extent to which organisms are able to exploit, avoid and manipulate the huge variation that exists in local climatic conditions, such as the cooler more stable temperatures occurring beneath a forest canopy, or the variation across the surface of a single leaf that can be as large as the thermal gradient between London and Madrid. Our preliminary results suggest that while this fine-scale climatic variation can buffer individuals, it may make ecological communities more prone to abrupt climate driven collapse. This means that – although organisms are individually plastic, the ecologically communities they form may behave more like crystals as species converge on similar fundamental limits to their resilience. This PhD project will test this idea using communities of butterflies and birds as model systems. The student will be based in the Centre for Biodiversity and Environment Research (UCL) and will be supported by a well-established research infrastructure, including postdoctoral researchers and international collaborators funded through ongoing grants from NERC and the Royal Society. There is much opportunity for the student to take the project in their own direction according to their interests, and to gain a broad range of fundamental and transferable skills; from physiological experiments, to fieldwork at our established sites in central Spain, to advance modelling.