Heimkehrer und Neubürger unter den Säugetieren der Niederlande im 19. und 20. Jahrhundert

2001

S. 155-170

32 Lit. Ang.

Unselbständiges Werk

200072818

Returning by mammal species can be differentiated as: (1) spontaneous recolonization by expansion from the remaining area of distribution, crossing national boundaries: (grey seal Halichoerus grypus, and wild boar Sus scrofa); (2) artifical reinroduction (beaver Castor fiber; otter Lutra lutra (planned for 2002), and Hamster Cricetus cricetus (planned for 2002 from breeding in captivity, as extinction is expected); (3) secondary recolonisation by expansion from reintroduced populations abroad (possibly the lynx Lynx lynx, as tracks are mentioned in the south-eastern part of the country. Reintroduction in the central part of the Netherlands is under discussion). Populations of exotic species may originate from: (1) expansion of the original area of distribution (no examples in The Netherlands); (2) animals escaped or released from captivity (Coypu Myocastor coypus; mink Mustela vision; Siberian chipmunk Tamias sibiricus; raccoon Procyon lator; Reever's muntjac Muntiacus reevesi); (3) expansion of introduced populations abroad (muskrat Ondatra zibethicus and raccoon dog Nyctereutes procyonoides). In general, exotic semi-aquatic species not dependent on unpolluted water, are much more successful than species relaying on wooded areas, as fragmentation and isolation of those areas is one of the main problems for Dutch nature conservation.