RSBP to Conduct Rat Removal Project at Henderson Island

The Royal Society for the Protection of Birds has committed to a project to eradicate Polynesian rats from the globally unique Henderson Island.

"We have raised £1.286m (1.788m USD) towards the £1.7m (2.36m USD) cost of the project, and have made a provisional decision to proceed with the operation in August 2011," said Jonathan Hall, Henderson Island project coordinator, said from his office in the United Kingdom.

The society needs to raise an additional £400,000 (556,074 USD) by next July to ensure before they can proceed with the project, Hall said.

"We are very excited to be on the cusp of carrying out this world-leading operation. At 37 km2, Henderson Island will be the largest tropical or sub-tropical island ever cleared of introduced rodents. The benefits from this single intervention will be enormous and long-lasting:

* the Henderson petrel saved from its slide towards extinction,

* the populations of four unique land-birds boosted,

* at least ten further unique species safeguarded for future generations, and

* a globally significant seabird sanctuary created.

Research suggests that seabird populations will increase up to a hundred-fold once rats are removed."

Online donations are being accepted, and any amount would be very much appreciated, Hall added.

During a mid-October visit to the Pitcairn Island group by Zegrahm Expeditions, a report prepared by Elizabeth Gould, expressed vividly the difference of not having rats present on Ducie Island, also an island in the Pitcairn group. Rats were eradicated here in 1997.

"The skies were filled with birds and one could not take a step upon the land without saying "excuse me" to a tiny chick or parent sitting on a nest—predominantly Murphy’s petrels, as well as dozens of sooty terns and a variety of other rare tubenoses, such as Christmas shearwaters, Herald petrels, Kermadec petrels, and Phoenix petrels. Zegrahm founder, Peter Harrison, was able to find and photograph the first pair of nesting Phoenix petrels found on this island since the 1920s. The phoenix petrel makes a nice metaphor for the recovery of the island after rat eradication."

Details of the pending project on the uninhabited Henderson Island, are available at the Society website. Henderson Island - a UNESCO World Heritage Site - is a Part of the Pitcairn Island group, a UK Overseas, Territory in the South Pacific.

Invasive House Crow Eradicated from Socotra Island

The House Crow Corvus splendens has been successfully removed from the island of Socotra, after ten years of work by the Environment Protection Authority (EPA) and Socotra Archipelago Conservation and Development Programme (SCDP).

"Eradication of the House Crow from Socotra has removed the risk posed to our native fauna", said Nadim Taleb - the National coordinator for the GEF, Governance and Biodiversity Mainstreaming Project.

House Crow accidentally arrived on Socotra via boat in the latter 1990s, and built up a breeding population of over ten pairs, posing a threat to native biodiversity of the island, designated a world natural heritage site in July 2008.

"The numbers of crows rose to 28 but a count in February 2004 found only 14, all in the capital, Hadibu," according to Richard Porter. Repeated attempts to trap the crows failed, so there was too much other food available.

An alternate to control and reduce the specie's population was successful.

Children were "paid YR1000 for each young crow they find. Eggs are not taken but left in the nest until they hatch and then the young collected," according to a published report by Porter. By 2004, "over 153 young" had been destroyed. "In addition YR2000 is paid for an adult crow, which encourages boys to kill them with catapults."

The nests containing young were taken to the Socotra Archipelago Conservation and Development Programme, according to Birdlife International. "The last birds were killed by a marksman this spring," according to Birdlife International.

"The Invasive Species Control Group freed Socotra from the invasive House Crow", said Omar Al Saghier, National Coordinator for GEF-Small Grant programme. The work was undertaken by the Invasive Species Control Group, the EPA and SADP using GEF-Small Grant programme funds.

Positive Changes for Rat Island Following Rat Removal

Nesting by a variety of birds at Rat Island are "early signs" that the removal of unwanted Norway rats has made the Aleutian Island a more suitable place for the local avifauna.

"Early signs of positive ecosystem change were documented" during a recent visit by U.S. Fish and Wildlife Service officials and other partners involved with the project. "Nests and chicks of black oystercatchers, glaucous-winged gulls, and common eiders were observed, in addition to a first-time record of breeding seabirds on an offshore rock previously inhabited by rats."

"Reports from the camp indicate that all bird species on the island except eagles are present in numbers similar to those found during pre-treatment surveys, according to a press release. "Falcons and gulls were observed successfully nesting on the island, and several observations of live adult and sub-adult eagles were made.

"Species such as murrelets, storm-petrels and puffins are expected to eventually recolonize the island if the rat eradication was successful.

"No living rats have been detected on the island, and the Service and its partners are cautiously optimistic that all of the rodents have been eradicated. If another year passes without a rat sighting, the team can declare the island rat-free for the first time in 229 years" since the rats were introduced due to a shoreline shipwreck.

Rat Island was treated in the fall 2008 with a bait containing the brodifacoum to remove the introduced Norway rats.

"A survey team dispatched to the island this May encountered a higher-than-expected number of carcasses of two non-target species. Biologists found 213 glaucous-winged gulls and 43 bald eagles. The team of biologists has reported no evidence of ongoing mortality on the island.

"The U.S. Fish and Wildlife Service has received laboratory results on an initial group of bird carcasses collected on Rat Island in late May and early April. Examination of the livers of two bald eagles, two glaucous winged gulls, one peregrine falcon, and one rock sandpiper all tested positive for the rodenticide brodifacoum."

F.W.S. officials are "in the process of analyzing all of the viable bird remains and tissue samples collected, in order to more fully understand the cause of mortalities and more effectively plan future operations in the Aleutians. Results will be released when they are available. In addition, soil and water samples were collected, and will be analyzed to more fully understand the potential movement of the rodenticide into, and degradation from, the ecosystem.

"The Service has no evidence that new mortalities have occurred. The partnership intends to dispatch a second team in early August to continue monitoring on the island."

Apparent Success for Rat Eradication at Aleutian Island

After a thorough survey of Rat Island, officials have found no sign of the Norway rats that had been present since they were introduced about 1780 when a Japanese ship wrecked on the beach, and the rats invaded.

"So far, no living rats have been observed," said Bruce Woods of the U.S. Fish and Wildlife Service, noting that seven observers walked the island looking for any indication of surviving rats. "We’re cautiously optimistic, but it’s a big island. It would be presumptuous to assume that we would have noticed rats if only a few were left."

A monitoring camp was established by biologists at the island on May 26, with results of the surveys reported June 10.

During the survey, several bird species, including Aleutian Cackling Geese, ptarmigan, Peregrine Falcons, and Black Oystercatchers were observed nesting on the ten-square-mile island.

The island will be surveyed again next year, before it is considered rat-free.

The goal was to restore the populations of seabirds and other parts of the native ecosystem.

"Restoring the natural habitat will likely bring back Tufted Puffins, Storm Petrels, Song Sparrows, Glaucous-Winged Gulls, Ancient Murrelets, and so many other important breeding seabirds," according to project sponsors. "Overall, the project will benefit at least 26 species of breeding birds, including at least 13 seabird species, some of which currently breed in small numbers on Rat Island or are restricted to breeding on small offshore islets."

Rat Island – comprising 6,861 acres is not inhabited and is located in the Aleutian Island Chain about 1,300 miles west of Anchorage, Alaska - is part of Alaska Maritime National Wildlife Refuge. It was treated in September 2008 when helicopters dropped 100,000 pounds of poison bait to eliminate the invasive rats, which preyed on bird eggs, chicks and small adult birds.

The island received its name due to its population of the rodents (Rattus norvegicus).

The visiting biologists also found "157 juvenile and 29 adult glaucous-winged gull carcasses and a total of 41 Bald Eagle carcasses that appear to have died in recent months. Seventy-five percent of the eagle carcasses appear to be juvenile birds."

The specific cause of death for these birds was not known.

"Several of the gull carcasses found initially are now at the National Wildlife Health Center’s laboratory in Madison, Wisconsin, and it is estimated that information on the cause of death will be available by late June," according to project officials. "Eagle carcasses and tissue samples were picked up from Rat Island by the refuge ship Tiglax on June 10 and will be shipped to the Wildlife Health lab after the ship makes port at Adak on June 11.

"Field personnel are in the process of collecting additional tissue samples for study before destroying any remaining bird carcasses to eliminate any possibility of ongoing risk. Reports from the camp indicate that all bird species on the island except eagles are present in equal or greater numbers than were counted during pre-treatment surveys. Although adult and juvenile eagles are still present on the island, numbers of sub-adult eagles are lower than pre-treatment totals."

None of the bird deaths happened recently, and Fish and Wildlife Service officials pointed out the losses "will not significantly impact" overall Aleutian bird populations. The agency estimates some 2,500 eagles live in the Aleutians, with gull numbers far higher.

In early May, a Partners in Conservation Award was presented to Rat Island Restoration Project, by Ken Salazar, Secretary of the Department of Interior, for this eradication effort.

The $2.5 million Rat Island Restoration Project, a partnership among the U.S. Fish and Wildlife Service, the Nature Conservancy, and Island Conservation, began operations in 2008 after a two-year planning process. This included an environmental analysis by federal regulators, who issued a Finding of No Significant Impact on April 15, 2008.

"Rat Island is the third largest of 250 islands world-wide where rats have been eradicated," according to F.W.S. officials. 

Gough Island Project to Investigate Eradicating Mice That Kill Birds

The Royal Society for the Protection of Birds has advertised online for the hiring of two senior research assistants for a project titled "Control of alien mice and plants at the Gough Island World Heritage Site."

The "mice are literally eating to extinction the populations of albatrosses, petrels and other birds," according to information on the RSPB website, and "achieved worldwide notoriety ... when the plight of Tristan albatrosses and Gough buntings was highlighted by the RSPB, ... albatross chicks were being eaten alive by the mice, stuck in their burrows as the mice launched their nocturnal attacks."

The research assistants "will be responsible for biological research to remove key areas of uncertainty for a proposed future attempt to eradicate house mice from Gough Island, monitoring of albatrosses and petrels, and to lead on the control and eradication of a small invasive plant from cliffs on Gough Island," during a period of 13 months, according to the online job description.

Gough Island, at Tristan da Cunha in the South Atlantic Ocean, is a world heritage site and its 10 million birds make it the most important seabird colony in the world, according to information on the RSPB website.

The United Kingdom government is funding a study of mouse eradication methods, with details for a project indicated in an online report.