The World in 2015: Economist (II)

choi

Alun Anderson, Death in the Far South; South Georgia takes on its rat.
www.economist.com/news/21631813- ... rat-death-far-south

("In 2013 and 2014 Team Rat baited two-thirds of South Georgia, so success lies close, with just one-third left to complete in 2015. Surprisingly, the £7.5m ($12m) project is being carried out by a small non-governmental organisation, the Dundee-based South Georgia Heritage Trust, which has raised 90% of its funds from donations, with only a little help from the British government. South Georgia is a British Overseas Territory, 850 miles east of the Falkland Islands and inhabited only in summer by visiting researchers. * * * 'Rats smell it from hundreds of metres away and go through thick and thin to get to it,' says Mr [Tony] Martin[, project leader and a professor at the University of Dundee]")

Note:
(a) Eradication Of Rodents. South Georgia & South Sandwich Islands, undated
www.sgisland.gs/index.php/(e)Eradication_Of_Rodents
("Rats eat the eggs and chicks of many ground-nesting bird species. As a result, the main island has been all but abandoned by" those birds)
(i) South Georgia and the South Sandwich Islands
en.wikipedia.org/wiki/South_Georgia_and_the_South_Sandwich_Islands
(a remote and inhospitable collection of islands; South Georgia "is by far the largest island in the territory. The South Sandwich Islands lie about 520 kilometres (320 mi) southeast of South Georgia"/ no permanent residents on the islands--the present inhabitants are the British government employees; Captain James Cook in 1775 claimed the territory for the Kingdom of Great Britain, and named it "the Isle of Georgia" in honour of King George III)
(ii) South Georgia pipit
en.wikipedia.org/wiki/South_Georgia_pipit
(a sparrow sized bird, only found on the South Georgia archipelago; is the only song bird in Antarctica)

(b) "Other islands have been cleared of rats, but the biggest of them, Macquarie Island south-east of Tasmania, is just one-tenth the size of South Georgia."

Macquarie Island
en.wikipedia.org/wiki/Macquarie_Island
(about half-way between New Zealand and Antarctic; Politically, it is part of Tasmania, Australia since 1900 [when 'six colonies federated, forming the Commonwealth of Australia' on Jan 1. 1901)

Quote: "The Australian/Briton Frederick Hasselborough discovered the uninhabited island accidentally [in] 1810 * * * He claimed Macquarie Island for Britain and annexed it to the colony of New South Wales [capital: Sydney] in 1810. The island took its name after Colonel Lachlan Macquarie, Governor of New South Wales from 1810 to 1821 [Macquarie University (public; 1964- ; in Sydney) is also named after that governor]. * * * In 1890, New South Wales transferred the island to Tasmania [which became a state on Jan 1, 1901.]

(c) James Cook (1728-1779; killed in Hawaii in a fight with Hawaiians during his third exploratory voyage)  Wikipedia

choi

Eradicating Invasive Rodents From South Georgia. In "SGHT Habitat Restoration Project." South Georgia Heritage Trust (a Scottish charity), undated (video)
www.sght.org/sght-habitat-restoration-project

Quote:

"at 100,000 hectares in size, the area of South Georgia to be cleared is more than eight times larger than Campbell Island (New Zealand), which at 11,300 hectares is the largest island ever cleared of rodents until now. However, as South Georgia’s rodent population is divided into a number of independent units by the island’s sea-level glaciers, eradication of all rodents is feasible. The eradication operation on South Georgia will require three helicopters, approximately 300 tonnes of rodent bait and three seasons to complete the work.

"Experience from other rodent eradication operations has demonstrated that the bait pellets to be used on South Georgia are extremely attractive to rodents; they will eat them in preference to their natural food. The active ingredient in the rodent bait pellets is called brodifacoum. It is an anti-coagulant, which causes the rodent to die of internal bleeding and organ failure. * * * Suffering by any animal is deeply regrettable

"The majority of the birds on South Georgia are seabirds that eat only marine prey; therefore, it is unlikely that they will consume the poison. Scavengers, such as skuas and giant petrels, could ingest enough poison through eating dead or dying rats to become ill themselves. However, rodents that take the bait become photophobic (scared of light) and consequently most die in their burrows, where they are inaccessible. Therefore, death of scavengers due to secondary poisoning is likely to be relatively rare. Streams and drinking water will not be affected because brodifacoum is not soluble in water.

brodifacoum
en.wikipedia.org/wiki/Brodifacoum
is no mystery. This class of chemicals, which we absorb from food (vegetable and animals) inhibits synthesis of vitamin k, which is needed to produce prothrombin etc to make blood clots. So brodifacoum gradually--because the existing prothrombin is not affected, it takes days for lack of production of prothrombin to show effects, which is worse and worse--causes the bleeding through every pores (bleeding in the brains bring about headache). The slow onset makes rat unaware what causes the problems, so they continue eating the bait. Vitamin K itself is the antidote to this class of chemicals.