Sally Poncet (South Georgia Surveys) and colleagues have published in the journal Polar Biology on the results of a survey of breeding giant petrels Macronectes spp. on South Georgia (Islas Georgias del Sur)*.

The paper’s abstract follows:

“Information on the status of giant petrels breeding at South Georgia was previously based on studies at a small number of the archipelago's breeding sites.  Here, we report the results of the first complete archipelago-wide survey of breeding northern Macronectes halli and southern M. giganteus giant petrels in the austral summers 2005/2006 and 2006/2007.  We estimate that 15,398 pairs of northern and 8803 pairs of southern giant petrels bred at South Georgia.  These are the largest and second largest populations at any island group, representing 71.0% and 17.3%, respectively, of updated global estimates of 21,682 pairs of northern and 50,819 pairs of southern giant petrels.  A comparison of counts at locations surveyed in both 1986/1987–1987/1988 and 2005/2006–2006/2007 indicated increases of 74% and 27% in northern and southern giant petrels, respectively, over the intervening 18–20 years.  The greater increase in northern giant petrels was likely influenced by the recovery of the Antarctic fur seal Arctocephalus gazella population at South Georgia, which provides an abundant but transient food resource (carrion).  Due to allochrony, this provides greater benefits to northern giant petrels.  The large, and increasing, population of king penguins Aptenodytes patagonicus at South Georgia also provides a potentially valuable food resource.  The flexible and opportunistic foraging behaviour of giant petrels has contributed to their positive population trends.  Other, more specialised, seabirds such as albatrosses have declined at South Georgia in recent decades mainly because of problems at sea, compounded by greater predation pressure from the increasing populations of giant petrels.”

A giant petrel displays on South Georgia (Islas Georgias del Sur)*, photograph by Kirk Zufelt

With thanks to Richard Phillips and Anton Wolfaardt.

Reference:

Poncet, S., Wolfaardt, A.C., Barbraud, C., Reyes-Arriagada, R., Black, A., Powell, R.B. & Phillips, R.A. 2019.  The distribution, abundance, status and global importance of giant petrels (Macronectes giganteus and M. halli) breeding at South Georgia.  Polar Biology doi.org/10.1007/s00300-019-02608-y.

John Cooper, ACAP Information Officer, 05 December 2019

*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.

Professor Denzil G.M. Miller, AM, PhD (30 May 1951 – 30 November 2019), a professorial fellow at the University of Wollongong and a Senior Adjunct Researcher at the University of Tasmania, passed away at his home in Tasmania last week at the age of 68.

Denzil Miller had a long career in Antarctic marine science and policy.  Raised in Zambia and Zimbabwe, he started his research career at South Africa’s University of Cape Town (where we were colleagues for a few years).  In 1979 he moved to the South African governmental marine environmental department where he conducted research in the Southern Ocean as a biological oceanographer.  We sailed together to Antarctic’s Prydz Bay in 1984 as part of South Africa’s contribution to the SIBEX 1 cruise of the international BIOMASS (Biological Investigations of Marine Antarctic Systems and Stocks) programme.  He trawled for Antarctic Krill Euphausia superba, I counted the birds around the vessel in between and at each sampling station; some evenings we drank beer.  From this, and other southern cruises, Denzil earned a PhD from the University of Cape Town for his important studies of krill.

Early in his career Denzil started taking managerial roles in addition to conducting research.  As Chair of the erstwhile Prince Edward Islands Management Committee he contributed to the drafting and completion of South Africa’s sub-Antarctic islands’ first management plan.  He also played an important role hosting and leading the South African Delegation to the final negotiation meeting that led to ACAP, held in Cape Town in early 2001.  I took the more lowly role of organizing the meeting and was grateful for his polite firmness when one delegation took political issue with the invitation list, and then another with the seating arrangements, leading to our having to move the tables to achieve an acceptable layout!

Shortly after the Cape Town meeting and the successful adoption of the Agreement’s text, Denzil and his family moved from South Africa to Australia to take up the position of Executive Secretary to the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) – for which he had previously served as Convener of its then krill working group (WG-Krill) and Chair of its Scientific Committee, while representing South Africa at both Scientific Committee and Commission meetings.  He served as Executive Secretary from 2002 to 2010, during which time we met up from time to time in both ACAP’s and CCAMLR’S home city of Hobart. One of our last meetings was when I gave an invited talk on the conservation crisis facing albatrosses and petrels from pirate longline fishing in the Southern Ocean as part of Hobart’s Antarctic Midwinter Festival.  Fittingly, I gave the talk in CCAMLR’S headquarters.

Denzil kept an association with CCAMLR towards the end of his career as a Board Member of the NGO Antarctic and Southern Ocean Coalition (ASOC), attending Scientific and Commission meetings on ASOC's Delegation from 2017 until this year.

Denzil Miller received a number of awards for his contributions to marine science and policy, including the no-longer issued South African Antarctic Medal in 1995 and the WWF [World Wide Fund for Nature] Duke of Edinburgh Conservation Medal in 2007.  He was made a Honorary Member of the Order of Australia in 2011 in recognition of his service to the conservation of Antarctic marine life.

Denzil receives the WWF conservation medal from the Duke of Edinburgh

Denzil leaves his wife Jenny, daughters Robyn and Hannah, son Richard and seven grandchildren.  ACAP extends its sincere condolences to them and to his colleagues who have worked ‘down south’ with him over many years.  Hamba kahle, Denzil.

A Celebration of the Life of Denzil Miller will be held on 12 December at the CCAMLR Headquarters in Hobart.

With thanks to Carol Jacobs.

John Cooper, ACAP Information Officer, 04 December 2019

James Russell (University of Auckland, New Zealand) and colleagues have published a Department of Conservation report that summarizes field work undertaken last summer on New Zealand’s sub-Antarctic Auckland Island preparatory to an attempt to eradicate House Mice Mus musculus.

The report’s abstract follows:

“Auckland Island is the last of the New Zealand subantarctic islands to have introduced mammals, including pigs (Sus scrofa), cats (Felis catus) and mice (Mus musculus), and its large size makes mouse eradication logistically challenging.  Therefore, it has been suggested that a lower bait sowing rate than is typically used for island rodent eradications should be applied and that eradication should be undertaken during summer, despite this being the rodent breeding season and alternative food being more readily available . In February 2019, we evaluated the effectiveness of this proposal by applying 4 kg/ha of non-toxic cereal bait containing the fluorescent dye pyranine across Falla Peninsula, Auckland Island, and trapping mice for 7 days using 13 live and kill trapping grids to determine their population status, density, home range size and bait uptake.  In addition, bait availability was concurrently monitored along 30 transects.  Mice were initially neophobic towards the trapping devices and thereafter were captured at low rates across both trap types.  Mouse density varied greatly across the grids (range = 26.4–105.6 mice/ha) and was independent of habitat type, and the home range radius of mice was estimated to be 34 m, although this was based on only one grid in coastal forest, where there was a medium density of mice.  Bait was still available on the ground in a potentially palatable condition at a density of > 1.2 kg/ha at 9 nights after bait application.  Only 2 of 232 mice (< 1%) that were caught within the treatment area showed no evidence of consuming bait, both of which were very small juveniles caught in tussock grassland.  Therefore, we believe they would have been vulnerable to a second application of bait approximately 4 weeks later once they were mature.”

Loading non-toxic, biomarker-laced mouse bait on Auckland Island, photograph by Finlay Cox

Read a popular account of the field work and an earlier ALN post.

Check outr a "story map" on the whole of the summer field work: looks positive for an eradication to go ahead!

Reference:

Russell, J.C., Griffiths, R., Bannister, W.M., Le Lievre, M.E., Cox, F.S. & Horn, S.R. 2019.  Mouse bait uptake and availability trials on Falla Peninsula, Auckland Island.  DOC Research and Development Series 363.  Wellington: Department of Conservation.  11 pp.

John Cooper, ACAP Information Officer, 03 December 2019

SPEA (Sociedade Portuguesa para o Estudo das Aves) is the national partner of BirdLife International in Portugal.  Ana Almeida is SPEA’s Marine Conservation Officer.  She wrote last month to ACAP Latest News describing trials of a new device to reduce seabird bycatch in fisheries: “we have first trialled the scary bird device (kite) in purse seiners, around a designated area for birds (Berlengas SPA [Special Protection Area]) and it showed positive results in decreasing interactions between birds and the boat/gear, especially for gulls.  The kite was attached to the main mast and not used all the time, to avoid habituation.  These first trials were taken under LIFE Berlengas Project.  This project is now reaching an end and we are finalizing reports and soon we will be submitting a paper with some of the obtained results.  Currently, we have a new project (MedAves Pesca) in the same area, to continue trialling mitigation measures for seabird bycatch.  We are now testing the scary bird device in longliners and gillnets."

The bird kite is flown above a purse seiner

Testing the kite with a long liner ...

... and with a gill net

Photographs by Elisabete Silva

More information on the 2018-2020 MedAves Pesca project edited from text in Portuguese from SPEA’s website comes courtesy of Google Translate:

“Bycatch of seabirds by fishing vessels is currently a major conservation issue worldwide and is often cited as one of the causes that has led to population declines of different species of seabirds.  The most recent estimates point to about 200,000 accidentally caught birds per year in European waters alone.

These incidental catches also have negative impacts on fishers, consuming too much crew time and damaging fishing gear.  It is therefore essential to establish partnerships between the fishing industry and the scientific community to find joint solutions.

Pioneering studies in Portugal have identified that gillnets, longlines and purse-seine nets are the fishing gear with the greatest impact on seabird populations.  Despite recent advances, there are still large knowledge gaps on this issue in our territory, which prevents a realistic assessment of the true impact of this threat.

This project, which runs from July 2018 to July 2020, aims to bridge part of this knowledge gap by analysing the overlap between fishing activity and seabirds in all five Special Protection Areas (SPAs) of the continent, thus identifying the areas most vulnerable to accidental catches.  For the Berlengas Islands SPA, where SPEA has been working in recent years, we already have this more detailed information available, and we can go a step further with the development and testing of mitigation measures for accidental catches.

Two innovative measures for gillnets and longlines will be developed and tested on board fishing vessels.  This work will be carried out in close collaboration with the fishing community of Peniche and aims to find fishery-accessible solutions that are easily implemented and will reduce bird catch in fisheries.”

Portugal is neither a Party to ACAP nor supports a breeding population of an ACAP-listed species.  However, the ACAP-listed and Critically Endangered Balearic Shearwater Puffinus mauretanicus, a Spanish breeding endemic, regularly migrates into Portuguese waters where it is at risk to fisheries (click here).

With thanks to Ana Almeida and Marc Parchow.

Reference:

Oliveira, N., Henriques, A., Miodonski, J., Pereira, J., Marujo, D., Almeida, A., Barros, N., Andrade, J., Marçalo, A., Santos, J., Benta Oliveira, I., Ferreira, M., Araújo, H., Monteiro, S., Vingada, J. & Ramírez, I. 2015.  Seabird bycatch in Portuguese mainland coastal fisheries: An assessment through on-board observations and fishermen interviews.  Global Ecology and Conservation 3: 51-61.

John Cooper, ACAP Information Officer, 02 December 2019