A digital GIS update to the classic Ulbrich's 1930 map of muskrat (Ondatra zibethicus) population range expansion in Central Europe

Historical data sets are valuable for learning and developing new tools for understanding and predicting species spread and dispersal. We update the classic Ulbrich (1930) map of muskrat (Ondatra zibethicus) spread in Central Europe, converting it to a set of GIS maps. We illustrate the updated data by fitting a set of simple models that measure the rate of spread of species. We recover the classic findings of radial spread from previous studies and, with the finer-scale data, show when the traditional radial assumption of spread breaks down. We believe that our version of the Ulbrich data is a valuable tool for pedagogy and a type of digital playground for the design and development of new tools to estimate species spread and dispersal.

Automated summary

Historical data sets are valuable for learning and developing new tools for understanding and predicting species spread and dispersal. By updating and converting the classic Ulbrich map into GIS maps, we are able to illustrate the rate of species spread and show the limitations of the traditional radial assumption using finer-scale data. We believe that our version of the Ulbrich data is a valuable tool for pedagogy and a digital playground for the design and development of new tools for estimating species spread and dispersal.