It’s too bad that Massachusetts officials have chickened out for now on a plan to create a colony of endangered timber rattlesnakes on uninhabited (by people)_ Mt. Zion Island in the Quabbin Reservoir. These creatures were once an important part of the ecosystem of the area, in part, believe it or not, as food for eagles and other creatures. They also helped control rodent populations, including deer mice, which host Lyme disease-carrying deer ticks.
You can't remove one part of an ecosystem without affecting the rest of it.
Their presence on the island would have also helped protect this little bit of wilderness by scaring off the worst and messiest predators in the area – people.