Nemesis came after 18 weeks of freedom.
Tracker dogs picked up a strong patch of rodent scent, and it was there that the conservationists uncloaked the finest weapon in their arsenal: a juicy chunk of penguin.
Rasputin's demise is science's gain, though.
Until now, field studies have focused on the risk of high-density populations of rats, in which juveniles escape because of competition for food and territory.
This is the first research into a single rat, and shows that a lone rat may behave quite unexpectedly, taking the risk of crossing open water to a new home even when its existing habitat is full of food and without predators.
"Eliminating a single invading rat is disproportionately difficult, not only because of atypical behavior... but also because bait can be less effective in the absence of competition for natural food resources," says lead author James Russell of the University of Auckland's Department of Conservation.
Primary Classification: Rattus (Rats)
Location: Worldwide
Habitat: Areas populated by humans, as well as forests and deserts.
Diet: Omnivorous
Size: Up to 10 inches in length and 1 lb in weight.
Description: Large, dark eyes; pointy noses; cupped ears; short fine hair on tails; long, slender bodies; back legs longer and stronger than their front legs; clawed feet covered with short, silky fur.
Cool Facts: They have glands on the bottom of their feet, so they leave a wet scent trail wherever they walk. They use their tails for many functions including balance, temperature control and communication.
Conservation Status: Common
