Possum-Killing Poison Helps Protect New Zealand Parrot

An endangered New Zealand parrot known as the kaka (Nestor meridionalis) has had a much-needed population boost after poisons were used to kill introduced possums, stoats and rodents in Waitutu Forest

Common brush-tailed possums (Trichosurus vulpecula) were introduced to New Zealand from Australia in 1870 for their fur and meat, but they overran the islands, threatening the country's native fauna, which evolved without any mammalian predators. A survey six years ago indicated that so many female kaka were being killed by possums that the birds were at risk of extinction in Waitutu Forest.

To help the parrots, last October the New Zealand Department of Conservation (DOC) dropped cereal pellets laced with a poison known as 1080 over 25,000 hectares of the forest. The results were dramatic. According to the DOC, possum populations within the area have dropped 99.5 percent. Populations of stoats and other rodents, also introduced species, dropped to a level so low, the animals could not be detected "with standard monitoring methods," the DOC reports.

The birds, meanwhile, are thriving in the absence of these predators. The DOC asserts that female kakas have nests full of healthy chicks, making this a record breeding season.

The DOC monitored the area before and after the 1080 drop and found that no birds were killed by the poison. Water samples also showed no signs of the biodegradable poison.

The use of the 1080 toxin has been highly controversial. Also known as sodium fluoroacetate, 1080 is derived from tea and is deadly to most mammals. It has been effective in New Zealand because there are no native mammals for it to kill, but some fear it is too indiscriminate and may pose an eventual danger to humans.

Kakas face threats from several other introduced species, including deer, pigs and wasps. The wasps eat shimmering honeydew, which is a primary source of the birds' diet, providing necessary energy for their breeding periods.

 

Formaldehyde: Poison could have set the stage for the origins of life

Formaldehyde, a poison and a common molecule throughout the universe, is likely the source of the solar system's organic carbon solids—abundant in both comets and asteroids. Scientists have long speculated about the how organic, or carbon-containing, material became a part of the solar system's fabric. New research from Carnegie's George Cody, along with Conel Alexander and Larry Nittler, shows that these complex organic solids were likely made from formaldehyde in the primitive solar system. Their work is published online April 4 by the Proceedings of the National Academy of Sciences.

"We may owe our existence on this planet to interstellar formaldehyde," Cody said. "And what's ironic about it is that formaldehyde is poisonous to life on Earth."

During the early period of the inner solar system's formation, much of the organic carbon that wasn't trapped in primitive bodies was lost to space, along with much of the water. Prior to this study numerous competing ideas emerged to explain the existence of primitive organic solids. Cody, of the Geophysical Laboratory, along with Alexander and Nittler, of the Department of Terrestrial Magnetism, and the team decided to study primitive solar system objects using advanced methods. What they discovered clearly pointed to a polymer formed from formaldehyde.

They tested their conclusion with experiments to reproduce the type of organic matter found in carbonaceous chondrites, a type of organic-rich meteorite, starting with formaldehyde. They found that their formaldehyde-synthesized organic material was not only similar to that found in carbonaceous chondrites, but also similar to organic material found in a comet named 81P/Wild 2, pieces of which were collected in space by NASA's Stardust mission, as well as in interplanetary dust particles, or particles from space that likely originated from comets and asteroids.

Their results make sense, because formaldehyde is relatively abundant throughout the galaxy and the polymerization process would have been possible under conditions of the primitive solar system.

"Establishing the likely origin of the principal source of organic carbon in primitive solar system bodies is extremely satisfying," Cody said.

Provided by Carnegie Institution