Pathways in Animal Invasions
Two main ways of dispersal of species can be distinguished: natural dispersal and anthropogenic spread, either indirectly or directly.Natural spread is usually slow and occurs within evolutionary times, it hardly crosses biogeographic borders, and is mostly undirectional. Anthropogenic dispersal is enabled or facilitated directly by human activities. This includes domestication and the worldwide spread of selected species, releases into the wild of suitable game, and escapes from captivity. Humans use animals for nutrition in multiple ways (farming, game, aquaculture and mariculture) and, as humans settle in the world, other species accompany them.More recent motivations to spread species worldwide include the demand for luxury and exotic products (e.g. fur farms), biological control and the pet trade. The main directions of anthropogenic dispersal until the 19th century were from Europe to the European colonies and many other parts of the world. Later, with the increasing independence of numerous countries, with growing world trade, and also with the actual step of globalization, species have been distributed to and from everywhere in the world.
KeywordsGrass Carp Ballast Water Sika Deer Grey Squirrel Nile Perch
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