Measuring the response of animals to contemporary drivers of fragmentation

From the perspective of most animals, fragmentation is a landscape-scale process in which habitat is separated into many smaller patches that have less total area. Here, we examine how two contemporary drivers of fragmentation, anthropogenic climate change and exurbanization, affect movement and responses of animal species to new environmental conditions. We address the definition of fragmentation and how the spatial patterns created by fragmentation can be measured at the scales at which different species of animals respond to their environments. We discuss tools, such as satellite remote sensing, that increasingly make it possible to identify and quantify changes in land cover and vegetation structure across extensive areas. We also describe a range of methods that are available to guide decisions about faunal surveys and monitoring programs in fragments or reference areas. Examination of stochastic changes in land cover and species occurrence over time is important because these shifts can confound detection of systematic responses to fragmentation. Careful evaluation of fragmentation and its influence on the distribution and viability of fauna may help to identify underlying mechanisms and to develop effective strategies for conservation and land use.