During the last 54 000 years, the range of red deer in Europe and the Ural Mountains changed in response to climate oscillations, generally decreasing in cooler periods and expanding in warmer periods, largely in agreement with the Expansion-Contraction model. However, these processes were asynchronous and differed in western and central regions when compared to eastern parts of Europe and the Ural Mountains.
Above: Red deer in the Białowieża Primeval Forest, Poland (Photo: Adam Wajrak)
The impact of climate changes on the distributions of red deer and other temperate mammal species is well recognized for the populations inhabiting western, south-western and southern Europe, but little is known about impacts of climate changes on mammal populations in eastern Europe. Our study, covering the whole continent and the Ural Mountains over 50 000 years, showed that the response of red deer to climate oscillations was different in western than in eastern Europe plus the Urals due to different environmental conditions in these areas. Easternmost Europe and the Urals were not covered by ice sheet during the Last Glacial Maximum (LGM) to such an extent as the western and central part of the continent. Consequently, much larger areas were available to terrestrial mammals, including red deer. Moreover, environmental niche modelling showed that during the LGM there were large areas suitable for red deer not only in western and southern Europe but also in eastern and south-eastern Europe in the vicinity of the Black Sea. We surmise that these areas were an important LGM refugium for temperate species such as red deer and the species recolonized eastern Europe from this region in postglacial times.
Cover paper: (read for free for a year) Niedziałkowska, M, Doan, K, Górny, M, et al. (2021) Winter temperature and forest cover have shaped red deer distribution in Europe and the Ural Mountains since the Late Pleistocene. J. Biogeogr. 48:147–159. https://doi.org/10.1111/jbi.13989
However, some of the results of the environmental niche modelling astonished us as they showed that some areas in the easternmost part of the continent and the Urals were not suitable for red deer during the last 50 000 years, although some red deer fossils dated to this time period were found there. The most probable explanation for this discrepancy is that, according to phylogenetic data, most of these red deer belonged to a more cold adapted red deer species: wapiti deer (Cervus canadensis).
Another interesting process took place during postglacial times. In western and central Europe red deer relatively quickly recolonized the area released by the glacier. However, recolonization was very different in the easternmost part of Europe, where clear disjunction appeared in the species range. Since the middle Holocene, red deer disappeared from the lower and middle Volga River region and later also in the Ufa region, to the west of the Ural Mountains. The last red deer were recorded in the Urals in the 19th century. The disappearance of the species in this part of the continent is probably related to climate and habitat changes. The contemporary easternmost border of red deer range in Europe runs parallel to the isoline of mean January temperature between −10 and −15°C, which is consistent with the 50 000 year-long climatic limits (mean January temperature below −10°C) of red deer found in this study.
Another explanation of the disappearance of red deer from eastern Europe and the Urals during the Holocene is west-east shift in range of wapiti deer, as was shown for other cold-adapted species such as the Siberian roe deer (Capreolus pygargus). Results of our study provide one more example that during at least the last 50 000 years the ranges of different species changed according to climatic oscillations not only in north-south but also west-east directions.
Future studies will enable checking of how other large mammal species have responded to climatic oscillations in eastern Europe during the last 50 000 years and how the geographical range of temperate mammals can change in the future due to present environmental changes.
Associate Professor, Mammal Research Institute Polish Academy of Sciences in Białowieża, Poland