Black
rats have prevented tortoises from breeding
November 2012. Galapagos National Park Service (GNPS) rangers and partners from
Island Conservation have begun to spread rat bait on South Plaza Island and
Pinzón Island.
No
tortoises have bred in the wild for 150 on Pinzon
Introduced black rats have prevented the giant tortoises on Pinzón Island from successfully reproducing in the wild for nearly 150 years, due to their predation on tortoise eggs and hatchlings. For the past 45 years, the GNPS and Charles Darwin Foundation have collected eggs, and artificially incubated, hatched, and raised the young in captivity. At four years of age, the young are considered "resistant" to attack by rodents and can be returned to their natural habitat. Since the first reintroduction of 20 young Pinzón tortoises in 1970, more than 550 juvenile tortoises have been released on the island. The rodent bait used in the project does not pose a risk to the tortoises.
Introduced black rats have prevented the giant tortoises on Pinzón Island from successfully reproducing in the wild for nearly 150 years, due to their predation on tortoise eggs and hatchlings. For the past 45 years, the GNPS and Charles Darwin Foundation have collected eggs, and artificially incubated, hatched, and raised the young in captivity. At four years of age, the young are considered "resistant" to attack by rodents and can be returned to their natural habitat. Since the first reintroduction of 20 young Pinzón tortoises in 1970, more than 550 juvenile tortoises have been released on the island. The rodent bait used in the project does not pose a risk to the tortoises.
The
Galapagos National Park Director, Edwin Naula, said, "Invasive species are
recognized as a major threat to the biodiversity of Galapagos, so the National
Park Service and its partners are using new techniques to remove these threats
and to prevent the extinction of species not found anywhere else in the world,
such as the giant tortoise of Pinzón."
Lava
lizards
Invasive rats also have had negative effects on the endemic Pinzon lava lizard, resulting in the decline of this unique species. On South Plaza Island, invasive rats destroy the root systems of the Opuntia cacti, a favorite food of Galapagos land iguanas and other endemic species such as the cactus finch.
Invasive rats also have had negative effects on the endemic Pinzon lava lizard, resulting in the decline of this unique species. On South Plaza Island, invasive rats destroy the root systems of the Opuntia cacti, a favorite food of Galapagos land iguanas and other endemic species such as the cactus finch.
Are
rodenticides safe?
The GNPS has received many inquiries regarding the risks of using anticoagulant rodenticides in protected areas. Before implementing eradication programs, the Park and its partners conduct thorough toxicity studies involving the species found on each of the islands where baits are to be applied in order to determine which species are at high, medium, or low risk. Mitigation plans have been implemented for such species as the Galapagos hawk, which are being kept in captivity for as long as the bait is considered toxic in order to protect them from primary exposure (by eating the bait) or secondary exposure (indirect contact from eating dead or live animals that have been poisoned).
The GNPS has received many inquiries regarding the risks of using anticoagulant rodenticides in protected areas. Before implementing eradication programs, the Park and its partners conduct thorough toxicity studies involving the species found on each of the islands where baits are to be applied in order to determine which species are at high, medium, or low risk. Mitigation plans have been implemented for such species as the Galapagos hawk, which are being kept in captivity for as long as the bait is considered toxic in order to protect them from primary exposure (by eating the bait) or secondary exposure (indirect contact from eating dead or live animals that have been poisoned).
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