Since the 1880’s, the Big Island has been home to the Small Asian Mongoose; a native of India.  They were brought here by owners of sugar cane plantations who were having problems with another invasive species; the rat.  Rats follow humans wherever we go and found their way to Hawaii as soon as someone showed up in a ship big enough for them to hide in.  The rat is a pest for many agricultural activities and the plantation owners were looking for a solution.

When they heard that some guy in Jamaica had success controlling rats by releasing a bunch of mongooses, they got some of their own.  It seemed to make sense.  The mongoose is a speedy predator and could make quick work of a lowly rat.  Just look at that face; he’s a killer alright.

Unfortunately the great benefit they heard about was sorely overstated.  The mongoose does its hunting during the day to take advantage of its high visual acuity.  The lowly rat, meanwhile, does most of its feeding and scurrying around during the night to take advantage of its night vision and superior sense of smell and touch.  So while the mongoose may be willing and able to kill a rat, the chances of them running into each other is pretty low.  Each is sleeping while the other is feeding.

Instead of eating all the rats, the mongooses went for any number of other prey including ground-nesting birds.  They may not have ate as many rats as hoped, but they sure did breed like them.  130 years later, the island is stuck with hoards of mongooses and the state bird is a threatened species.

We humans seem to have a knack for creating a problem and then making it worse because we jumped on a solution that sounded right without checking to see if it would really help.