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A brave new world with a wider view Researchers have long attempted to follow animals as they move through their environment. Until relatively recently, however, such efforts were limited to short distances and times in species large enough to carry large batteries and transmitters. New technologies have opened up new frontiers in animal tracking remote data collection. Hussey et al. review the unique directions such efforts have taken for marine systems, while Kays et al. review recent advances for terrestrial species. We have entered a new era of animal ecology, where animals act as both subjects and samplers of their environments. Science , this issue 10.1126/science.1255642 , 10.1126/science.aaa2478

Restrictions on roaming Until the past century or so, the movement of wild animals was relatively unrestricted, and their travels contributed substantially to ecological processes. As humans have increasingly altered natural habitats, natural animal movements have been restricted. Tucker et al. examined GPS locations for more than 50 species. In general, animal movements were shorter in areas with high human impact, likely owing to changed behaviors and physical limitations. Besides affecting the species themselves, such changes could have wider effects by limiting the movement of nutrients and altering ecological interactions. Science , this issue p. 466

The importance, extent, and mode of interspecific gene flow for the evolution of species has long been debated. Characterization of genomic differentiation in a classic example of hybridization between all-black carrion crows and gray-coated hooded crows identified genome-wide introgression extending far beyond the morphological hybrid zone. Gene expression divergence was concentrated in pigmentation genes expressed in gray versus black feather follicles. Only a small number of narrow genomic islands exhibited resistance to gene flow. One prominent genomic region (<2 megabases) harbored 81 of all 82 fixed differences (of 8.4 million single-nucleotide polymorphisms in total) linking genes involved in pigmentation and in visual perception-a genomic signal reflecting color-mediated prezygotic isolation. Thus, localized genomic selection can cause marked heterogeneity in introgression landscapes while maintaining phenotypic divergence.

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Many of the world's migratory animals are in decline. This essay explores the unique scientific and political challenges of protecting migratory species while they are still common.

Movement ecology and the integration of ecology, behavior and biomechanicsRecent advances in mechanistic modeling and tracking technology have enriched our capacity to disentangle the key parameters affecting movement processes and to characterize movement patterns accurately. These advances set the stage for integrating the four existing paradigms for studying movement -the random, biomechanical, cognitive and optimality approaches ( Fig.1) -in the form of a new cohesive 'movement ecology' framework . The biomechanical paradigm elucidates the machineries that enable individuals or propagules to move, including their physical mechanics, energetics and physiology, and thus focuses on the study of the motion capacity of individual organisms. The cognitive paradigm explores the mechanisms of gathering, processing and responding to the environment in a way that produces nonrandom movement in time and space and thus focuses on the navigation capacity of the individual. The optimality paradigm examines the relative efficacy of different movement strategies in optimizing some particular fitness currencies (e.g. energy gain or survival) over ecological or evolutionary timescales, and thus focuses mostly on the external factors affecting the internal state of the individual. The random paradigm analyzes the fit of observed animal tracks to various random walk models to assess, for example, search efficiency and thus focuses exclusively on the movement patterns. The movement ecology framework explicitly combines these basic components of movement and the links among them ( Fig.1) , which can be identified across all movement types and taxonomic groups . Thus, this framework offers a template for transdisciplinary integration of the four existing movement research paradigms ( Fig.1) to create jointly the new paradigm of movement ecology, devoted to the comprehensive study of all biological (whole-organism) movement phenomena. Movement ecology thus aims at unifying organismal movement research and aiding the development of a general theory of wholeorganism movements . To facilitate this unification, we need tools that can provide simultaneous information about the movement, energy expenditure and behavior of the studied organisms, and the environmental conditions they SummaryIntegrating biomechanics, behavior and ecology requires a mechanistic understanding of the processes producing the movement of animals. This calls for contemporaneous biomechanical, behavioral and environmental data along movement pathways. A recently formulated unifying movement ecology paradigm facilitates the integration of existing biomechanics, optimality, cognitive and random paradigms for studying movement. We focus on the use of tri-axial acceleration (ACC) data to identify behavioral modes of GPS-tracked free-ranging wild animals and demonstrate its application to study the movements of griffon vultures (Gyps fulvus, Hablizl 1783). In particular, we explore a selection of nonlinear and decision tree methods that include support vector mach...

Summary 1.Measurements of phytohemagglutinin (PHA)-induced tissue swelling are arguably the most popular surrogates for immunocompetence in wild birds. It is largely unresolved, however, whether the basic assumption underlying these measures is valid, particularly whether more swelling represents a 'better' or 'stronger' cell-mediated immune response. 2. In this study we took a first step towards such validation by characterizing immune cell infiltration over time into the wing-webs (patagia) of PHA-challenged House Sparrows ( Passer domesticus ). Relative to saline-injected wing-webs, PHA-injected wingwebs displayed intensive infiltration of many immune cell types, including basophils, eosinophils, heterophils, lymphocytes, macrophages and thrombocytes. The abundance of most of these cell types changed over the course of the swelling response (6 -48 h postinjection). Peak infiltration time varied depending on cell type. At several time points, significant correlations between the numbers of some cell types (particularly heterophils) and the degree of swelling were detected. 3. Together, these data indicate that PHA-induced swelling is related to heightened immune cell activity in House Sparrows, but also that the PHA swelling response in this species is dynamic and involves both innate and adaptive components of the immune system. We thus caution against interpreting larger swellings as 'greater cell-mediated immunocompetence', given the complex nature of this immune response.