ACAP Latest News has previously reported a number of times on ongoing efforts to remove introduced Reindeer Rangifer tarandus from South Georgia (Islas Georgias del Sur)* in the South Atlantic with an aerial survey last month confirming that at least 21 animals remained on the island (click here).  News is now in that the alien herbivore may have been finally eradicated from the island with a total of 44 being shot by marksman this year on the Barff Peninsula.  As a consequence vegetation is recovering in the absence of Reindeer to the eventual advantage of burrowing petrels, including the ACAP-listed White-chinned Petrel Procellaria aequinoctialis.

Reindeer on South Georgia with King Penguins, photograph by Martin Collins

Environment Officer Jennifer Lee’s account is given below.

“Following many years hard work of planning, and two years of field operations, in January two marksmen from the Norwegian Nature Inspectorate (SNO) made one final sweep of the Barff Peninsula in order to locate and shoot any reindeer that remained.

The two SNO marksmen on newly named Ranger Ridge

One of the marksmen searching for any remaining reindeer on the Barff Peninsula. Photograph from SNO

The operation to eradicate reindeer from South Georgia began in 2013.  A combination of herding and ground shooting were used in the Busen area with Sami herders gathering around 1,000 animals and SNO ground shooters removing another 1,000 animals from areas where the terrain meant herding was not possible.  As shooting in the Busen area took less time than anticipated, marksmen were also deployed on the Barff Peninsula where a further 1,555 reindeer were killed.  The following year, a team of six marksmen worked to remove the remaining reindeer on the Barff Peninsula and were successful in shooting 3,140 animals.

In the months since the main cull of the Barff heard took place, field parties and aerial searches had been undertaken to determine how many reindeer remained and where they were located. In January 2015 two of the SNO marksmen returned to conduct a final sweep. Just prior to their arrival HMS Dragon visited the island and identified a group of 21 reindeer close to the tip of the peninsula.  In an incredible feat of efficiency and professionalism, within 6 hours of being deployed to the field, the two marksmen [had] shot these 21 animals and harvested some of the meat ready for collection the next day by staff from KEP.

As expected, in the absence of reindeer, vegetation has started to recover from the severe overgrazing it had been subject to for more than 100 years.  Interestingly, the marksmen were able to use this to their advantage and could often determine where the reindeer were located by looking at the height and composition of the vegetation.  In areas where even a small number of reindeer persisted, the grass was short and cropped whereas the valleys, which had had a year to recover, were lush and thickly vegetated.

Early signs of vegetation recovery now the reindeer have gone. Photograph from SNO

In the subsequent three weeks, the marksmen worked their way south and shot a further 15 animals at Penguin Bay, 5 at the top of Sorling Valley and 3 close to St Andrews Bay.  This brings the total number of reindeer killed on the Barff Peninsula to 4,739, and the total number of reindeer eradicated on South Georgia to over 6,700.  In the coming weeks, eagle eyed field workers and helicopter pilots will continue to search for any signs of reindeer.”

Reference:

Lee, J. 2015.  Clean sweep?  South Georgia Newsletter January 2015.

John Cooper, ACAP Information Officer, 24 February 2015

*A dispute exists between the Governments of Argentina and the United Kingdom of Great Britain and Northern Ireland concerning sovereignty over the Falkland Islands (Islas Malvinas), South Georgia and the South Sandwich Islands (Islas Georgias del Sur y Islas Sandwich del Sur) and the surrounding maritime areas.

Helen Gummer (Department of Conservation, Wellington, New Zealand) and colleagues have published in the journal Global Ecology and Conservation on successes achieved in bringing back the threatened Chatham Petrel Pterodroma axillaris from the brink.

The paper’s abstract follows:

“Conservation of gadfly petrels, some of the most threatened seabirds, is frequently dependent on long-term research and management.  We review 20 years of a program preventing the extinction of the Chatham petrel (Pterodroma axillaris), a New Zealand endemic once declining due to intense burrow competition from another native seabird. Breeding success in the early 1990s was unsustainably low (10–30%).  Recovery measures started in 1992 when Chatham petrel burrows were converted and artificial entrances blockaded to exclude broad-billed prions (Pachyptila vittata).  Pair and burrow fidelity were enhanced, though prions still posed a threat during Chatham petrel chick-rearing.  Breeding success improved when prions were culled, however a less intensive and contentious solution was to introduce burrow flaps in 2001 which reduced interference from prospecting prions.  Subsequently, breeding success increased to a mean 80% per annum.  Finding burrows, primarily using radio-telemetry, increased those under management from eight in 1990 to 217 in 2010 when spotlight surveys indicated 72% of juvenile birds had fledged from managed burrows.  Chick translocations to two other islands and increasing population size (from 200–400 birds in 1990 to an estimated 1400 birds by 2010) has improved the species IUCN status from Critically Endangered in 1990 to Endangered in 2013."

Chatham Petrel, photograph by Don Merton

Graeme Taylor holds a Chatham Petrel chick, photograph by Helen Gummer

Reference:

Gummer, H., Taylor, G., Wilson, K.-J. & Rayner, M.J. 2015.  Recovery of the endangered Chatham petrel (Pterodroma axillaris): A review of conservation management techniques from 1990 to 2010.  Global Ecology and Conservation 3: 310-323.

NOTE:  Starting with this item, ACAP Latest News will from time to time report on efforts to conserve gadfly petrels in the genus Pterodroma where it is thought that findings or techniques are relevant to efforts to conserve ACAP-listed species, especially the burrowing petrels of the genus Procellaria.

John Cooper, ACAP Information Officer, 23 February 2015

 . Seabird McKeon (Smithsonian Marine Station at Fort Pierce, Florida, USA) and colleagues postulate open access in PeerJ PrePrints that sightings of Atlantic seabirds, including of Manx Puffinus puffinus and Great P. gravis Shearwaters, in the North Pacific may be due to the loss of summer ice in the Arctic opening up the Northwest Passage as a route between the two oceans.  Based on their model it may be that North Pacific seabirds, such as the Laysan Albatross Phoebastria immutabilis, could reach the North Atlantic.

The paper’s abstract follows:

Accelerated loss of sea ice in the Arctic is opening routes connecting the Atlantic and Pacific oceans for longer periods each year.  These changes will increase the ease and frequency with which marine birds and mammals are able to move between the Pacific and Atlantic ocean basins.  Indeed, recent observations of birds and mammals suggest these movements are already occurring.  Reconnection of the Pacific and Atlantic Ocean basins will present both challenges to marine ecosystem conservation and an unprecedented opportunity to examine the ecological and evolutionary consequences of faunal exchange in real time.  To understand these changes and implement effective conservation of marine ecosystems, we need to further develop modeling efforts to predict the rate of dispersal and consequences of faunal exchange.  These predictions can be tested by closely monitoring wildlife dispersal through the Arctic Ocean and using modern methods to explore the ecological and evolutionary consequences of these movements.”

Laysan and Black-footed Albatrosses, photograph by Eric Vanderwerf

Reference:

McKeon, C.S., Weber, M.X., Alter, S.E., Seavy, N.E., Crandall, E.D., Barshis, D., Fechter-Leggett, E.D. & Oleson, K.L.L. 2015.  Melting barriers to faunal exchange across ocean basins.  PeerJ PrePrints.  http://dx.doi.org/10.7287/peerj.preprints.835v1.

John Cooper, ACAP Information Officer, 22 February 2015

Twenty-two Laysan Albatross Phoebastria immutabilis chicks have disappeared over the past three weeks from a wildlife refuge on the USA’s island of Kauai, with feral Domestic Cats Felis catus being suspected as the culprits (click here and here).

A Laysan Albatross incubates its egg on Kauai, photograph by Hob Osterlund

As a consequence traps have been set and so far eight cats have been caught.  “We’ve noticed the mortality has subsided since we’ve removed eight cats,” said Michael Mitchell of the Kauai National Wildlife Refuge Complex.  The complex includes the Kīlauea Point National Wildlife Refuge where 115 to 130 pairs of Laysan Albatrosses breed unprotected by a predator-proof fence that would keep out cats, as has proved successful at the Kaena Point Natural Area Reserve on the nearby island of Oahu (click here and here).

A live-trapped cat

As well as the suspected cats killing chicks, domestic dogs Canis familiaris running loose have from time to time killed numbers of adult Laysan Albatrosses on Kauai (click here).

Unlike some of the other main Hawaiian islands Kauai apparently does not have an established population of alien Small Indian Mongoose Herpestes javanicus, a known seabird predator, although two animals were live-trapped on the island in 2012 (click here).

To view photos and accounts of Laysan Albatrosses breeding on Kauai visit My Albatross Diary, the Kaua’i Albatross Network and The Albatross of Kaua’i.  There's also a live-streaming webcam, in its second year, that is keeping watch on two Laysan nests, currently with small chicks (click here and here).  

John Cooper, ACAP Information Officer, 21 February 2015