India, Nov. 1 -- In 1884, St. Croix had a rat problem in its sugarcane fields, and a small predator seemed like the perfect answer. According to a study in the journal Oryx by Nicole Angeli and Lee Fitzgerald, small Indian mongooses were brought to the island to control those rats. Over the following decades, a native lizard disappeared from nearly all of its historic range there, and mongooses had a hand in that.

St. Croix is about 218 square kilometers (roughly 21,800 hectares). Between 1754 and 1800, its plantations shifted from cotton to sugarcane. Rats became a problem in those fields, so mongooses were released in 1884 to control them. The island's landscape was changing too. By 1917, nearly 90% of the island's native forests and w...