The Joys of people introducing creature that don't belong or removing ones that should stay!
Australia has a history of this.
When the first europeans got going in Australia and wanted something to shoot at, they didn't want to shoot at the roo's (too big, to fast, and skippy might attack!
) So they imported a dozen rabbits, they managed to shoot six of them but they missed the others, we now have millions of their offsping causing problem (but less so with some of the management plans that have been used)
After having fun with rabbits, they decided they wanted a proper fox hunt, so in came the foxes, and again they missed knocking them all off (the booze gave the foxes a fighting chance!) and they've been a problem ever since.
Then there are the others, Camels - out of 250 different species of plant life in the desert they can eat 248 of them! At leat we are now exporting them back to the middle east!
Cane toads- to help get rid of one pest with introduce another, guess what? it didn't work. Now causing problems in three states, they only benift that these ugly buggers can give is help with your golf swing!
(and a nick name for state!)