Ecuador is to begin dropping poison bait to target 180 million invasive rats on Pinzón island and an adjacent islet in the Galapagos archipelago today, the Associated Press reports. “It’s one of the worst problems the Galapagos have. (Rats) reproduce every three months and eat everything,” according to a Nature Conservancy specialist involved in the operation quoted by the news service. Read the full AP report.
The bait has been specially formulated and tested for targeting exclusively at rats, according to conservationists on the project. Galapagos hawks on the island have been rounded up for a period of safekeeping, to prevent accidental deaths from swallowing poisoned rodents.
Today’s mass raticide begins the second phase of an ambitious program to eradicate introduced rats from the iconic Galapagos, an island chain of volcanic cones about 600 miles west of South America. The Galapagos is famous for its unique wildlife, including giant tortoises, marine iguanas, sea lions, albatrosses, and Darwin’s finches. The animals found by Charles Darwin on his visit to the islands in the early 1800s played a formative role in the development of his thinking about evolution.
The Galapagos is also the venue for regular cruises hosted by Lindblad/National Geographic Expeditions. Thousands of passengers on the cruises have supported the Lindblad/National Geographic conservation fund which in turn supports projects such as the eradication of rats and other invasive species from the islands.
The black rat (Rattus rattus), which was accidentally introduced to the archipelago by pirates and/or whalers in the 17th or 18th centuries, and the brown rat (Rattus norvegicus), are currently among the most serious threats to Galapagos biodiversity, according to the Galapagos Conservancy website. “Introduced rats, both black and brown, wreak havoc among the wildlife of Galapagos by preying on eggs and hatchlings of bird and reptile species, to such an extent that one species of Galapagos tortoise has had no natural recruitment for nearly a century, and some unique bird species have become critically endangered. Their control and possible eradication in specific sites is a major priority for conservation in the islands,” the Conservancy explains.
The Conservancy believes that recent successes in rodent eradications on a number of small- and medium-sized islands “provided conservation managers sufficient knowledge and expertise to carry out the planned rat eradication on Pinzón in 2012, with little risk to native fauna and flora.”
The seven-square-mile (1815-hectare) Pinzon is home to giant tortoises (approximately 100 of the original old natives and an estimated 250 repatriated tortoises ranging in age from 5-40 years old), snakes, lava lizards, hawks and owls, passerine birds including several species of Darwin’s finches, and endemic invertebrates and vegetation, the Galapagos Conservancy website says. “Recent toxicological studies on reptiles and experience in maintaining hawks in captivity during the period of risk (method used during eradication on Rábida and other small islets) have filled those knowledge gaps and helped quantify and mitigate potential risk to non-target species,” the Conservancy says.
“Phase one of the project—assessing the potential risk to non-target species, calibrating the application rate of toxic baits and logistical planning—has been completed. Phase two, the shortest and most expensive part of the work, is the application of approximately 40 tons of bait by means of helicopter. The final phase of the project will be long-term monitoring of ecosystem recovery.”
For a timeline of rats in the Galapagos, visit the Galapagos Conservancy’s Rat Eradication on Pinzon in 2012 website.