Conservation paradox: Invasive species are often threatened in their native range

Non-native species introduced by humans are among the main causes of global species decline -- they were partly responsible for 60 percent of the species that have become extinct worldwide in recent decades. In Central Europe, non-native mammals include species such as the Norway rat, the mouflon and the mink. Now a study shows that some of these species introduced by humans are themselves endangered in their native range.