Last month ACAP Latest News reported that New Zealand invasive species expert John Parkes was to undertake a feasibility study for the eradication of House Mice Mus musculus on South Africa’s Marion Island in the southern Indian Ocean during the annual relief of the island’s meteorological and research station (click here).  John recently returned from the island on the annual relief after completimg his study and has replied to five questions put to him by ALN on his impressions of Marion and of the task ahead.

John Parkes heads south for the feasibility study

How was the field work?

It was of course great to see the island - and the mice.  I was interested to see if there were mice up in the high-altitude 'polar desert' and confirmed their presence there, which means the whole island will need to be baited.  It was very useful to talk to members of the scientific and meteorological staff present on the island.  The photos of mouse-attacked Grey-headed Albatrosses Thalassarche chrysostoma by Ben Dilley and Peter Ryan of the FitzPatrick Institute, University of Cape Town reinforce the case already made by Andrea Angel and John Cooper in their 2011 report that the mice need to be eradicated.

Is eradication feasible?

Yes, the mice can be eradicated.  Mice have been eradicated from 60 islands around the World including several sub-Antarctic islands such as Macquarie, Enderby and Coal Islands.

Confidence that it is possible on Marion will be improved if the recent attempt on parts of South Georgia (Islas Georgias del Sur)* prove successful and if the intended eradications on Antipodes, Gough and Steeple Jason, Falkland Islands (Islas Malvinas)* succeed.  In fact of the 20 mouse eradication attempts made on islands since 2007 around the World only one has failed - probably due to reinvasion.  This is a great improvement on attempts made before 2007 - when about a third had failed.

Are their research needs prior to an eradication attempt?

Several questions need to be answered for Marion.  A major question is what time of year should an eradication attempt be made.  Tradition has it that winter is the best time to undertake rodent eradications on temperate islands because the rodents are then at their hungriest and are not breeding.  But winter on Marion has short days, many days on which helicopters cannot fly, and although the mice are not breeding and their numbers are reducing from their autumn peak densities, the per capita food supply may actually be better for the survivors than when they have to compete with lots of their fellows.

So a question to be resolved is whether a late summer - early autumn baiting might be better, as was the case for Enderby Island and for South Georgia (Islas Georgias del Sur)*.  Some traditional bait-acceptance trials might be conducted in April during an annual relief.  These use non-toxic bait marked with a dye that is spread in an area where mice have been trapped and tagged.  They are then retrapped after baiting to see if 100% have eaten baits.

How did you find the quarantine procedures?

The South Africans take biosecurity seriously and try to stop new plants and animals arriving on their islands.  However, if mice are finally eradicated from Marion the effort required to make sure they (or rats) do not get back needs some further thought.  Current early detection-rapid response procedures at sites where supplies are unloaded from containers and nets on the island seem adequate for invertebrates, but what would the staff do if a mouse hopped out of an opened container ashore post-eradication?  The risks of such events occurring are low, but the responses in place to stop a hitch-hiking mouse from scuttling off into the wild require some extra effort.

What were your overall impressions?

A fascinating place - few species of native plants but great to see the seals and birds.  The Wandering Albatross Diomedea exulans has to be my favourite bird!  South Africa has very few islands but the Prince Edward group must be the gem.

Wandering Albatross and chick on Marion Island, with mouse-free Prince Edward in the background 17 km away

Selected Literature:

Angel, A. & Cooper, J. 2011.  Review of the Impacts of the House Mouse Mus musculus on sub-Antarctic Marion Island, Prince Edward Islands.  Report to the Prince Edward Islands Management Committee, South African National Antarctic Programme.  Rondebosch: CORE Initiatives.  57 pp.

Angel, A., Wanless, R.M. & Cooper, J. 2008.  Review of impacts of the introduced House Mouse on islands in the Southern Ocean: are mice equivalent to rats?  Biological Invasions 11: 1743-1754.

Jones, M.G.W. & Ryan, P.G. 2010.  Evidence of mouse attacks on albatross chicks on sub-Antarctic Marion Island.  Antarctic Science 22: 39-42.

Parkes, J. 2008.  A feasibility study for the eradication of House Mice from Gough Island.  RSPB Research Report No. 34.  Sandy: Royal Society for the Protection of Birds.  51 pp.

Wanless, R.M., Cooper, J., Slabber, M.J. & Ryan, P.G. 2010.  Risk assessment of birds foraging terrestrially at Marion and Gough Islands to primary and secondary poisoning.  Wildlife Research 37: 524-530.

John Cooper, ACAP Information Officer, 28 May 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.

The ACAP-listed White-chinned Petrel Procellaria aequinoctialis is the bird most commonly recorded as fisheries bycatch by longline and trawl fisheries in the Southern Ocean.  Although currently listed as globally Vulnerable, it has been suggested that limited population trend data provide some grounds for uplisting the species to Endangered, with the decision dependent largely on better information from South Georgia (Islas Georgias del Sur)*, which is believed to hold more than half of the World’s population.  At Bird Island, there was a decrease of 28% (equivalent to 2% per year) in nesting burrow occupancy from the late 1970s to the late 1990s.

Based on existing tracking data, the greatest overlap between adult birds and fisheries, and therefore the greatest risk of bycatch, occurs on the Patagonian Shelf during the pre-laying period, and on the Patagonian Shelf and off southern Chile during the non-breeding period.  However, non-breeders (10 birds) have been tracked in only one year, and stable isotope analysis of feathers from a larger sample suggests that a small proportion also spend the winter in the Benguela Upwelling region off the west coast of southern Africa.  Nothing is as yet known about the movements of newly-fledged birds.

To remedy this gap in knowledge, 13 chicks were fitted with small satellite transmitters (PTTs, made by Telonics) last month on Bird Island and are being tracked in near real-time using the Argos system.  The tagging will enable monitoring of the routes they take as they search for food sources.  Their movements are being added to a map which is updated daily (click here).

The greatest risk to these birds lies on the Patagonian Shelf where most of them appear to be heading.  The distances covered in the first few weeks after fledging are already in excess of 9000 kilometres.  The tracking is part of a wider study that involves attaching geolocators to birds to track non-breeding movements and at-sea activity patterns of adults in the South Atlantic.

White-chinned Petrels on Bird Island, photographs by Andy Wood 

With thanks to Andy Wood, British Antarctic Survey, Cambridge, UK for information and photographs.

Selected literature:

Phillips, R.A., Silk, J.R.D., Croxall, J.P. & Afanasyev, V. 2006.  Year-round distribution of white-chinned petrels from South Georgia: relationships with oceanography and fisheries.  Biological Conservation 129: 336-347.

Mackley, E.K., Phillips, R.A., Silk, J.R.D., Wakefield, E.D., Afanasyev, V. & Furness, R.W. 2011.  At-sea activity patterns of breeding and nonbreeding white-chinned petrels Procellaria aequinoctialis from South Georgia.  Marine Biology 158: 429-438.

Martin, A. R., Poncet, S., Barbraud, C., Foster, E., Fretwell, P. & Rothery, P. 2009.  The white-chinned petrel (Procellaria aequinoctialis) on South Georgia: population size, distribution and global significance.  Polar Biology 32: 655-661.

Phillips, R.A., Bearhop, S., McGill, R.A.R. & Dawson, D.A. 2009.  Stable isotopes reveal individual variation in migration strategies and habitat preferences in a suite of seabirds during the nonbreeding period.  Oecologia 160: 795-806.

John Cooper, ACAP Information Officer, 29 May 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.

Graeme Elliott (Science and Capability Group, Department of Conservation, Nelson, New Zealand) and colleagues have published a report in the New Zealand Department of Conservation’s DOC Research and Development Series on research conducted preparatory to the planned attempt to eradicate House Mice Mus musculus on Antipodes Island next year.

The report’s abstract follows

“The eradication of house mice (Mus musculus) from subantarctic Antipodes Island is likely to present many challenges, but of particular concern is the potential impact on resident non-target terrestrial and marine bird species.  Therefore, the likely impacts of the proposed eradication operation were examined in July 2013.  Non-toxic baits containing the biotracer pyranine were distributed over 6 ha of the island at a density of 16 kg/ha.  The density of mice and levels of bait uptake were then measured on three trapping grids, two within and one external to the bait distribution area.  All mice that were captured in the two trapping grids in the baited area at Reef Point returned positive results for pyranine.  In contrast, 1 snipe (Coenocorypha aucklandica meinertzhagenae), 9 pipits (Anthus novaeseelandiae steindachneri), 17 Reischek’s parakeets (Cyanoramphus hochstetteri) and 16 Antipodes Island parakeets (Cyanoramphus unicolor) that were captured within the Reef Point study area showed no signs of having eaten the baits.  Pyranine was, however, found in bird faeces collected within the bait distribution area, which predominantly originated from blackbirds (Turdus merula) and song thrushes (Turdus philomelos), along with small numbers of pipits. Pipits were also observed eating small quantities of bait and producing faeces containing the biotracer.  Scavenging species such as brown skua (Catharacta antarctica lonnbergi), kelp gulls (Larus dominicanus) and northern giant petrels (Macronectes halli) appeared to show no interest in the baits or, in the case of northern giant petrels, dead mice.  Bait persistence trials were also conducted, and population monitoring of mice, parakeet species, pipits, snipe and invertebrates are reported on, along with captive husbandry techniques and observations of the diet of parakeets.  Finally, a list of recommendations for minimising non-target impacts and carrying out monitoring prior to and following mouse eradication is provided.”

An Antipodean Albatross pair on the Antipodes, photograph by Erica Sommer

Winter in the Subantarctic is a short film recorded on the 2013 expedition which describes the research then undertaken in preparation for the eradication of mice and restoration of the island.

Reference:

Elliott, G.P., Greene, T.C., Nathan, H.W. & Russell, J.C. 2015.  Winter bait uptake trials and related field work on Antipodes Island in preparation for mouse (Mus musculus) eradication.  DOC Research and Development Series No. 345.  34 pp.

John Cooper, ACAP Information Officer, 28 May 2015

The National Marine Fisheries Service (NMFS) of the United States has reported the incidental take of a globally Vulnerable Short-tailed Albatross Phoebastria albatrus in the logline fishery of the Bering Sea/Aleutian Islands Management Area (BSAI).  The bird was taken on 16 December 2014.

The albatross take was not reported to the NMFS observer on the vessel, nor was the bird retained by the vessel crew.  The bird was later identified by NMFS as a Short-tailed Albatross with the assistance of seabird experts who reviewed video of the bird taken onboard the vessel. The last two documented Short-tailed Albatross fatalities from a longline fishing vessel were recorded in Alaskan waters in September 2014 (click here).

Short-tailed Albatrosses gather off the Aleutians, photograph by Rob Suryan

“The short-tailed albatross is protected in Alaska waters by the Endangered Species Act (ESA).  As a result of consultation with the US Fish and Wildlife Service (USFWS) under the ESA, USFWS issued an incidental take statement of four birds during each two-year period for the BSAI and Gulf of Alaska (GOA) hook and-line groundfish fisheries. In instances where the amount or extent of incidental take is exceeded, reinitiation of formal ESA consultation is required.  This is the third take in the two-year period that began on September 16, 2013. To-date, the incidental take levels have not been reached during the current or any previous Biological Opinions.

The NMFS Alaska Regional Office, NMFS North Pacific Groundfish Observer Program, and the USFWS are actively coordinating efforts and communicating with each other in response to this take incident and are complying to the fullest extent with ESA requirements to protect this species.  NMFS is also working closely with the freezer longline fleet in which the bird was taken, to evaluate what additional actions can be taken by the fleet to avoid further takes.  To assist in this coordinated effort, NMFS reminds operators of hook-and-line vessels in the BSAI and GOA that they are required to employ multiple seabird avoidance measures.  NMFS encourages vessel operators to consider not deploying gear amidst congregations of endangered birds; if possible, move on to a location where you don’t see the short-tailed albatross.

Ed Melvin, a seabird mitigation gear researcher and specialist from Washington Sea Grant, reiterated that in order to keep birds from baited hooks in windy conditions that the streamer line on the windward side should be maintained to windward of the groundline and with a minimum of 200 feet of the line with streamers in the air. This configuration can be achieved by maintaining sufficient drag using a skid buoy with a 10-pound weight fixed at the nose of the buoy. It is this aerial extent of the streamer line with streamers attached that scares birds. The use of round buoys for this purpose should be avoided, as their position astern can be erratic. Also, individual streamers should be long enough to extend to the water. Given that all vessels are different, he recommends that each vessel purchase extra tubing to adjust streamer length as necessary and to make repairs if streamers are damaged. Each crew should have one person in the setting crew responsible for bird avoidance. Additionally, when short-tailed albatross are around the vessel, an additional crew member at the roller may be helpful. NOAA Fisheries also reminds vessel operators that when an observer is on-board, any short-tailed albatross caught by hook-and-line gear be retained and reported immediately to the NMFS observer.” (click here).

Click here for detailed information on seabird avoidance measures in US longline fisheries.

John Cooper, ACAP Information Officer, 27 May 2015