A team from the University of Minnesota Raptor Center went to the Galapagos Island of Pinzon to exterminate black rats that have been decimating the tortoises. The giant tortoises (Pinzon Tortoise) are classified as “extinct in the wild” by the International Union for Conservation of Nature (IUCN) because of the introduction of these invasive rats, likely seomtime in the 17th century by pirates or whalers. The rats prey on eggs and hatchlings of birds and reptile species. Because the team wanted to poison the rats, they first had to capture all of the Galapagos hawks which feed on the rats. The hawks were held for six weeks until the risk of exposure to the rat proison was reduced. For more than 45 years the Galapagos Naitonal Park and the Charles Darwin Foundation have raised Pinzon Tortoises in captivity and returned them to the wild at about 4 years old, when they are considered rat-proof.