Original sentence: During the 1960s, South Korea began to export these animals to Europe as pets.In the 1970s there were sightings in parks in Europe, and a number of small populations have become resident in suburban forests and urban parks in Belgium, France, Switzerland, Germany, Italy, the Netherlands, and Austria
Edited sentence: By the 1970s, the Siberian chipmunk inhabited suburban forests and urban parks in Belgium, France, Switzerland, Germany, Italy, the Netherlands, and Austria.During the 1960s, South Korea began to export these animals to Europe as a part of the pet trade.Human introduction is a major risk for the spread of this species into other forests and areas.Siberian chipmunks were found only in their native range of Eastern Asia until the 1960s, when this species was introduced to European countries