Poaching can have devastating impacts on animal and plant numbers, and in many countries has reached crisis levels, with illegal hunters employing increasingly sophisticated techniques. We used data from an 8-year study in Savé Valley Conservancy, Zimbabwe, to show how geographic profiling-a mathematical technique originally developed in criminology and recently applied to animal foraging and epidemiology-can be adapted for use in investigations of wildlife crime. The data set contained information on over 10,000 incidents of illegal hunting and the deaths of 6,454 wild animals. We used a subset of data for which the illegal hunters' identities were known. Our model identified the illegal hunters' home villages based on the spatial locations of the hunting incidences (e.g., snares). Identification of the villages was improved by manipulating the probability surface inside the conservancy to reflect the fact that although the illegal hunters mostly live outside the conservancy, the majority of hunting occurs inside the conservancy (in criminology terms, commuter crime). These results combined with rigorous simulations showed for the first time how geographic profiling can be combined with GIS data and applied to situations with more complex spatial patterns, for example, where landscape heterogeneity means some parts of the study area are less likely to be used (e.g., aquatic areas for terrestrial animals) or where landscape permeability differs (e.g., forest bats tend not to fly over open areas). More broadly, these results show how geographic profiling can be used to target antipoaching interventions more effectively and more efficiently and to develop management strategies and conservation plans in a range of conservation scenarios.

The ring-necked parakeet Psittacula krameri is one of the best-known invasive species in the UK. It is also arguably the species whose origins as an invasive have been the subject of the greatest speculation, with explanations ranging from birds escaping from the set of the film 'The African Queen' to animals being released in Carnaby Street in London by Jimi Hendrix in the 1960s. Here, we use geographic profilinga statistical technique originally developed in criminology to prioritise the large lists of suspects typical in cases of serial crime such as murder, rape and arson, but more recently applied to ecology and conservation biologyto analyse the spatial patterns of the ring-necked parakeet, from the first detailed records in the 1960s to the 21st century and ask whether spatial analysis supports these hypotheses. We show that, despite the undoubted appeal of the different hypotheses concerning their origin, spatial analysis provides no support for any of them, leading us to conclude that the birds' establishment in Britain is more likely to be a consequence of repeated releases and introductions, a view supported by a detailed search of the British Newspaper Archive. More generally, our study shows how geographic profiling can be used to understand the spatial patterns of biological invasions over time.

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Geographic profiling, a mathematical model originally developed in criminology, is increasingly being used in ecology and epidemiology. Geographic profiling boasts a wide range of applications, such as finding source populations of invasive species or breeding sites of vectors of infectious disease. The model provides a cost-effective approach for prioritizing search strategies for source locations and does so via simple data in the form of the positions of each observation, such as individual sightings of invasive species or cases of a disease. In doing so, however, classic geographic profiling approaches fail to make the distinction between those areas containing observed absences and those areas where no data were recorded. Absence data are generated via spatial sampling protocols but are often discarded during the inference process. Here we construct a geographic profiling model that resolves these issues by making inferences via count data, analyzing a set of discrete sentinel locations at which the number of encounters has been recorded. Crucially, in our model this number can be zero. We verify the ability of this new model to estimate source locations and other parameters of practical interest via a Bayesian power analysis. We also measure model performance via real-world data in which the model infers breeding locations of mosquitoes in bromeliads in Miami-Dade County, Florida, USA. In both cases, our novel model produces more efficient search strategies by shifting focus from those areas containing observed absences to those with no data, an improvement over existing models that treat these areas equally. Our model makes important improvements upon classic geographic profiling methods, which will significantly enhance real-world efforts to develop conservation management plans and targeted interventions.

than a thousand V-2 rockets struck Great Britain, causing 2,754 deaths and 6,523 injuries.. Unlike the V-1, the V-2 could not be shot down, and M.I.5 responded with an ingenious scheme to mislead the Germans about the impact sites so they would shorten the range, missing Westminster and the docks. This is widely regarded as a success, with claims that the M.P.I. moved eastwards by two miles a week, ending outside London and saving 1,300 lives. Here, we use geographic profiling-a statistical technique originally developed to prioritise large lists of suspects in cases of serial crime-to show that this deception had little or no effect. Our results suggest rockets aimed at a single target would form clusters of 30 km radius, swamping the claimed movement. Our study shows how geographic profiling may be applied to diverse data sets beyond criminology and epidemiology.