Dynamics of large mammal range collapse and extinction: evidence from the Holocene record of Europe

Developing an increased understanding of the ecology of species decline and extinction is imperative in the current age of escalating global biodiversity loss. However, although meta-analyses have begun to provide substantial new insights into correlates of extinction risk in well-studied vertebrate groups, relatively little remains known about fundamental aspects of the extinction process, such as the biogeography of range contraction and collapse in endangered species. In particular, existing databases typically exclude extinct species and populations, and so contain biases which make extinction-proneness studies difficult to interpret. Large-scale studies of extinction that also incorporate data from the recent past therefore have the potential to provide unique new insights into key patterns and processes of extinction and hence inform both early warning systems and management interventions. Possibly the best source of data for such studies is the Holocene record of Europe. Faunal and environmental changes across the Holocene, a period of relative climatic stability but rapid human expansion, are documented by extensive zooarchaeological, palaeontological and historical records spanning the last 11,500 years. The Holocene archaeology of Europe, in particular, has been the subject of substantial continent-wide research: extensive data on changing patterns of prehistoric human population density, resource use and environmental impacts, and also on changing patterns of large mammal occurrence and distribution, are available across the region. However, although several large mammal species have experienced severe Holocene range collapse, regional extirpation or global extinction, previous studies have addressed Holocene mammal population change almost entirely in terms of qualitative reviews of species- or region-specific case studies with minimal wider-scale ecological analysis. This study system therefore has the potential to provide extensive new insights into fundamental processes driving large-scale range contractions and fragmentations, regional extirpations and global extinctions of mammal species in response to human impacts. Insights gained from comparative studies of past and present mammal ecology can also inform current mammal conservation and re-wilding efforts, and can be used to generate predictive models of species responses to environmental shifts driven by anthropogenic impacts and future climate change. The proposed project will combine data from a series of different academic fields to develop a novel interdisciplinary research programme for understanding the long-term dynamics and drivers of mammal range decline and extinction in response to increasing anthropogenic threats. The student will compile data on past mammal distributions and associated human impacts from the literature and from examination of existing museum collections, as the basis for quantitative investigation of the correlates and dynamics of changing patterns of species persistence across the Holocene of Europe. This will permit GIS-based analysis of range declines across a range of environmental variables displayed by species with differing ecology, life history and trophic status, and will address whether common patterns exist for range contraction, fragmentation and/or refugium formation. Statistical investigation of the quality of Holocene data will be provided by analysis of the zooarchaeological and subfossil records of species that remain widely distributed across the region today. Analysis of local last-occurrence data across the ranges of regionally extirpated or globally extinct species will also form the basis for investigating whether critical thresholds of human impact, e.g. human population density, can be identified. These related studies will ultimately form the basis for intercomparisons between the past and present that can inform conservation planning for today's endangered mammal species.