A year forward from this week, the long-awaited attempt to eradicate “killer” House Mice Mus musculus on Gough Island will commence by the UK’s Royal Society for Bird Protection (RSPB).  Success will give the Critically Endangered Tristan Albatross Diomedea dabbenena – and other breeding seabird species - a chance to recover their numbers, following years of attacks by the mice (click here).

“One year from today we’ll pack our bags, load the S.A. Agulhas II with four helicopters, all the equipment and supplies we need and set sail to Gough Island. After years of planning we mark this important and exciting milestone, one year until the mouse eradication departs. Thank you all for your support!

Since mice were first filmed preying upon on seabirds on Gough Island and rapidly driving some species towards extinction, we have been planning a mouse-eradication operation. With our expert partners we’ve assessed the risks, planned the complex logistics of shipping a seemingly endless list of equipment to an island via a seven-day ship journey, and have started building a strong team of some of the most knowledgeable people in the world of island restorations.

Today is an important day for us as we start counting down to the operation itself. No doubt it will come round very quickly, and there is still a lot of work to do and your support is needed more than ever! Although we can never guarantee success, we are well prepared, leaving nothing to chance, doing everything we can to ensure a successful outcome for Gough Island and its seabirds.”*

A Tristan Albatross chick on Gough Island is attacked by mice at night, photograph by Ross Wanless

Read more about the mice and their depredations on Gough’s birds in ACAP Latest News here and watch a recent video of a mouse attack on an Endangered Atlantic Yellow-nosed Albatross chick.

*Quoted text edited for style and grammar.

John Cooper, ACAP Information Officer, 18 May 2018

Verónica Cortés (Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Spain) and Jacob González-Solís have published in the on-line/open-access journal PLoS One on seabird mitigation trials conducted on Mediterranean longliners.

The paper’s abstract follows:

“High numbers of seabirds are killed annually worldwide in longline fisheries. In the Mediterranean, this mortality is seriously affecting the viability of seabird populations, in particular of the three endemic shearwaters. Even so, there is currently no specific seabird mitigation requirements for the longline fleet operating in this area. From 2013 to 2014, we assessed the efficiency and practical applicability of four mitigation measures on artisanal demersal longliners targeting European hake (Merluccius merluccius) in the western Mediterranean: night setting, tori line, weighted lines and artificial baits. We performed fifty-two pairs of experimental (with the tested mitigation measure) and control settings (without any measure), and compared their effects on seabird interactions and fish catches. In addition, we estimated the longline sink rates and the seabird access area to baited hooks in different longline configurations. Night setting reduced bycatch risk without affecting target and non-commercial fish catches. The tori line may have reduced the bycatch risk by displacing bait attacks beyond the end of the line, but at this distance shearwaters could still access to the baits and the streamers did not deter birds under calm wind conditions. Weighted lines increased sink rate, but it resulted in only a minor reduction of the seabird access window to baited hooks and led to some operational problems during the setting. Artificial baits substantially reduced commercial catches. Moreover, the seabird access to the baited hooks was influenced by the longline configuration, the setting speed and the relative position to the floats and weights. So far, night setting stands out as the best mitigation measure for reducing bycatch levels without compromising target catches in demersal longliners. Ideally, these results should be confirmed in longliners targeting species other than European hake.”

An Yelkouan Shearwater Puffinus yelkouan caught on a Mediterranean longline hook, photograph by Vero Cortés

Reference:

Cortés, V. & González-Solís, J. 2018. Seabird bycatch mitigation trials in artisanal demersal longliners of the Western Mediterranean. PLoS One doi.org/10.1371/journal.pone.0196731.

John Cooper, ACAP Information Officer, 17 May 2018

Maria Petry (Laboratório de Ornitologia e Animais Marinhos, Universidade do Vale do Rio dos Sinos, São Leopoldo, Brazil) and colleagues have published in the journal Antarctic Science on the seabird population trends at Stinker Point on the Antarctic Peninsula, including of the ACAP-listed Southern Giant Petrel Macronectes giganteus.

The paper’s abstract follows:

“Available information about seabird breeding population trends on Stinker Point (Elephant Island, Maritime Antarctic Peninsula) is outdated by decades. This study reports current numbers of breeding species, and evaluates population trends over 28 years. We counted breeding pairs of seabirds along all ice-free areas on Stinker Point during two distinct periods (summers of 1985/86–1991/92 and 2009/10–2013/14). Thirteen species currently breed in the area: four Sphenisciformes, four Procellariiformes, one Suliforme and four Charadriiformes. Chinstrap penguin Pygoscelis antarcticus has the highest number of breeding pairs (4971±590), followed by gentoo penguin Pygoscelis papua (1242±339). Comparisons between the two intervals showed declining trends for almost all breeding populations, although southern giant petrels Macronectes giganteus are experiencing a subtle population growth. Population decreases in locations with low human disturbance, such as Stinker Point, may indicate sensibility to climate and environmental change and need further investigation.”

Southern Giant Petrel and downy chick at Stinker Point

Reference:

Petry, M.V., Valls, F.C.L., Petersen, E.S., Finger, J.V.G. & Krüger, L. 2018. Population trends of seabirds at Stinker Point, Elephant Island, Maritime Antarctica. Antarctic Science doi.org/10.1017/S095410201800013.

John Cooper, ACAP Information Officer, 16 May 2018

The South Georgia Heritage Trust (SGHT) announced last week that South Georgia (Islas Georgias del Sur)* is deemed to be free of rodents after a long campaign “with some bird species already showing very dramatic signs of recovery” (click here).

The Habitat Restoration Project to eradicate Norway Rats Rattus norvegicus and House Mice Mus musculus was conducted over three separate summer seasons, starting in 2011 and concluding in 2015, as has been detailed in many postings to ACAP Latest News (click here).

Poison bait gets flown ashore by helicopter; photograph from Tony Martin

Infographic courtesy of South Georgia Heritage Trust: 8000 teabags!

Following the aerial baiting by helicopter of a total of 108 723 ha, a monitoring survey was carried out this last austral summer, searching for signs of surviving rodents using 4600 chewsticks and tracking tunnels, and three trained sniffer dogs and their two handlers – with many hundreds of kilometres walked.  No signs of rats or mice were detected after six months in the field.

Two low-lying, vegetated areas in the north-west of the island, Cape Rosa and Nunez Peninsula that are separated by a rodent-proof glacier, supported only House Mice – the only mice occurring on the island. Their areas of sheer rock were not poison baited. Baited areas were 1754 ha for Cape Rosa and 3178 ha for the Nunez Peninsula. The latter appears to be the largest “island” so far from which mice as the only predator have been successfully eradicated. Previously in the Southern Ocean, the largest “mouse-only” island that has been successfully treated was New Zealand’s 2100-ha Antipodes Island, announced as mouse free in March this year (click here).

The success with eradicating mice from an area of over 3000 ha gives hope to developing plans to eradicate House Mice on 6500-ha Gough Island next year – another “mouse-only” island (click here).

Anton Wolfaardt holds up two rats as Mark Tasker looks on, 8 January 2012; photograph by Sally Poncet

The news was also announced by the UK Delegation to the Sixth Session of the ACAP’s Meeting of Parties in South Africa last week – to general acclaim.

Read more and view photos of the eradication success here and here.

With thanks to Tony Martin and Mark Tasker.

John Cooper, ACAP Information Officer, 15 May 2018

*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.