Going west—invasion genetics of the alien raccoon dog Nyctereutes procynoides in Europe

Abstract

The raccoon dog, a medium-sized carnivore, has long been recognised as a prominent example of an invasive alien species in Europe with a wide distribution, significant ecological impact and remarkable dynamics of spread at both national and continental scales. We conducted a study of genetic diversity of 73 individuals collected at 20 sites across North and Central Europe to (1) identify major phylogenetic lineages and (2) elucidate spatial patterns of population genetic structure. Reconstructed phylogenies reveal two major clades differing on average by Tamura-Nei corrected distance of 3.4% for a 599-bp segment of the mitochondrial control region corresponding to a coalescence time of approximately 457,800 years ago (95% CI, 223,300-773,900). Many expectations based on introduction history, such as the presence of signatures of repeated founder effects and subsequently rapid population expansion, were not confirmed by our demographic analyses, probably due to an insufficient amount of time since translocations. Nevertheless, global F ST =13.9% and landscape approaches provided evidence for weak population genetic structure that followed a pattern of isolation by distance. Finally, we found no congruence between previously reported morphological differentiation and the sorting of mtDNA variation. We therefore conclude that an exceptional combination of factors including multiple translocations, secondary contact and admixture of divergent matrilineages, as well as natural processes of colonisation associated with a wide ecological tolerance, promoted the successful spread of the raccoon dog into Europe.

Home ranges of raccoon dogs (Nyctereutes procyonoides, Gray, 1834) in Southern Brandenburg, Germany

“…Beginning in 1928 in the Ukraine and continued in the 1940s and 1950s, a total of about 9,000 individuals of Nyctereutes procyonoides ussuriensis were released into the European part of the former USSR (Nowak 1973). From here, the raccoon dog began its successful expansion to Fennoscandia and Western Europe (Pitra et al 2010). In Germany, the first individuals were recorded in the 1960s (Nowak 1973).…”

Population genetic study of the raccoon dog (<i>Nyctereutes procyonoides</i>) in South Korea using newly developed 12 microsatellite markers

“…The raccoon dog (Nyctereutes procyonoides, family Canidae) is endemic to East Asia, but was introduced to Europe in the early 20 th century (Pitra et al, 2010). N.…”

Re-examination of the fossil raccoon dog (<i>Nyctereutes procyonoides</i>) from the Penghu channel, Taiwan, and an age estimation of the Penghu fauna

“…Another study based on mitochondrial genetics estimated subclades within the continental population (using the Russian raccoon dog N. p. ussuriensis, which was introduced to Europe), suggesting a division around 457800 years ago (ranging from 223300 to 773900 BP) (Pitra et al, 2010). These researchers also estimated the diversification between the Russian and Japanese raccoon dogs (N. p. viverrinus) at around 870000 years ago (ranging from 480000 to 1370000 BP) (Pitra et al, 2010).…”

“…Another study based on mitochondrial genetics estimated subclades within the continental population (using the Russian raccoon dog N. p. ussuriensis, which was introduced to Europe), suggesting a division around 457800 years ago (ranging from 223300 to 773900 BP) (Pitra et al, 2010). These researchers also estimated the diversification between the Russian and Japanese raccoon dogs (N. p. viverrinus) at around 870000 years ago (ranging from 480000 to 1370000 BP) (Pitra et al, 2010). Together, these studies, along with our results based on morphological examination, suggest that the Penghu fauna is older than the last glacial maximum (20000 BP) and is younger than 870000 BP, which corresponds to the Middle to Late Pleistocene (190000 BP, estimated by the appearance of Crocuta crucuta ultima in East Asia) (Ho et al, 1997;Chang et al, 2015), although molecular and morphological divergence could have occurred at different times, and age estimation via 'molecular clocks' is not entirely accurate.…”