Edward Abraham and colleagues (Dragonfly Data Science, Wellington, New Zealand) have produced a report for the New Zealand Department of Conservation on the demographic parameters of 12 albatross taxa that breed within New Zealand.

The report’s executive summary follows:

“The New Zealand Department of Conservation is developing a seabird threat framework, “to better understand, and manage, at-sea threats to our seabirds”.  This framework will allow the impact of threats on seabird populations to be qualitatively assessed, and will be used to prioritise a programme of seabird population monitoring.  As a first stage in developing the framework, a database of demographic parameters and threats was prepared.  In this project, a process was established for reviewing and synthesising this information.  The demographic parameters were then used to develop an online tool, which allowed for the impact of changes in parameters on population growth rates to be assessed.  In the future, this tool will allow the impact of current and potential threats on seabird populations to be promptly explored.  The process was trialled on the 12 albatross taxa recognised by the New Zealand Threat Classification System: Gibson’s wandering albatross (Diomedea antipodensis gibsoni); antipodean wandering albatross (Diomedea antipodensis antipodensis); southern royal albatross (Diomedea epomophora); northern royal albatross (Diomedea sanfordi); Campbell Island mollymawk (Thalassarche impavida); New Zealand white-capped mollymawk (Thalassarche cauta steadi); Salvin’s mollymawk (Thalassarche salvini); Chatham Island mollymawk (Thalassarche eremita); grey-headed mollymawk (Thalassarche chrysostoma); southern Buller’s mollymawk (Thalassarche bulleri platei); northern Buller’s mollymawk (Thalassarche bulleri bulleri); and light-mantled sooty albatross (Phoebetria palpebrata).  An online survey was conducted, with 16 seabird researchers invited to review the albatross demographic data. Of these researchers, seven participated in the survey.  A statistical model was then used to estimate the demographic parameters, and the population growth rate was estimated through a matrix population model.  A web application was built that provides these demographic estimates as a base case, allowing the user to explore how changes to the parameters affect the population growth rate.  For most albatross species, there was a wide uncertainty, both in the demographic parameters and in the population growth rate.  The growth rate of Gibson’s wandering albatross was negative (a mean annual population growth of -4.7%, 95% c.i.: -9.5 to -1.0), aligning with results from more detailed modelling.  The uncertainty of the growth rates of all other taxa included zero, and so this analysis could not differentiate whether or not their populations were stable.  The parameters will continue to be updated as more information becomes available.”

Buller's Albatrosses at The Snares, photograph by Jean-Claude Stahl

Reference:

Abraham, E., Yvan, R. & Clements, K. 2016.  Evaluating Threats to New Zealand Seabirds, Report for the Department of Conservation.  Wellington: Dragonfly Data Science.  19 pp.

John Cooper, ACAP Information Officer, 11 April 2016

Sarah Gutowsky (Dalhousie University, Halifax, Canada) has submitted her thesis in partial fulfilment of the requirements for the degree of Doctor of Philosophy that looks at analysing at-sea movements of Black-footed Phoebastria nigripes and Laysan P. immutabilis Albatrosses.

The thesis abstract follows:

“Wide-ranging pelagic seabirds are among the most threatened and most mobile of all marine taxa.   Understanding their movement ecology is necessary to develop effective conservation solutions for declines, yet many drivers of their movements throughout the life cycle are poorly understood. Particularly, movements during two critical life stages are known in little detail for many species: the period of post-natal dispersal for fledglings and the non-breeding period for adults.  Biologging technologies provide means to study individual at-sea movements during all life stages.  However, advances in analytical approaches for examining biologger data have in some cases lagged behind that of the technologies themselves.  The objectives of my thesis are to address weaknesses in our understanding of seabird movement ecology and in the approaches used to describe seabird movement from biologger data, using two threatened seabirds, the Laysan Phoebastria immutabilis and black-footed P. nigripes albatrosses, as models.  In Chapter Two, I describe for the first time the movement and habitat of black-footed albatross fledglings, and compare with those of non-breeding adults.  In Chapter Three, I develop an approach to assess detailed activity budgets for non-breeding seabirds, and apply this method to explore drivers of non-breeding movements for both model species.  In Chapter Four, I evaluate the limitations of a common approach where period-specific space use for a group, such as a colony, is inferred from a sample of biologger-equipped individuals.  In Chapter Five, I build a conceptual framework of the drivers of movement with a focus on the albatross family (Diomedeidae), and apply this to identify trends and weaknesses in the literature on albatross movement.  My work demonstrates the value of taking a holistic view of seabird movement ecology; interpreting observed movement patterns requires considering multiple interacting factors that drive individuals to move, including intrinsic factors, such as age, breeding phase, and moult status, as well as how “decisions” are made of when and where to move, and what modes of movement are used.  Biologging tools afford insights into these drivers of movement, especially when the individual nature of biologger data is considered in analyses, with implications for ecological understanding and conservation.”

Black-footed Albatrosses dance with Laysan Albatrosses behind, photograph by Pete Leary

Reference:

Gutowsky, S.E. 2016.  Pelagic seabird movement ecology: assessing drivers of albatross (Diomedeidae) movement and the utility of biologging tools for wide-ranging and threatened seabirds.  PhD thesis.  Halifax: Dalhousie University.  171 pp.

John Cooper, ACAP Information Officer, 08 April 2016

Tony Martin’s new book (authored along with “Team Rat”) tells the stirring story of ridding South Georgia (Islas Georgias del Sur)* of introduced rodents by aerial bombardment of a thousand square kilometres with 12 500 bags of poison bait from three vintage helicopters.  It relates, in word and image, the baiting work that took place on the island in three phases (in 2011, 2013 and 2015) that has been regularly reported in in ACAP Latest News (click here).  The book has been produced to help raise funds for the final and crucial phase of the project that will conduct monitoring next year to confirm - or not - that the island’s Norway Rats Rattus norvegicus and House Mice Mus musculus are finally gone.

Snow- and ice-clad mountains rear behind a Wandering Albatross on Prion Island, photograph by Anton Wolfaardt

The three phases of the eradication, depicted in green (Phase One) and red (Phase Two top, Phase Three bottom)

The Author’s Preface says the book “is a story of highs and lows, excitement and frustration, fear and astonishment, and lots of plain hard graft.”  It also shows how such a big island, far larger than any previously treated, could be successfully baited in phases due to glaciers impenetrable to rats dividing the island into zones.  Retreating glaciers, presumed due to climate change, were putting rat-free areas at risk so it was essential the eradication was not delayed.

I much enjoyed reading Tony’s book – and admiring the stunning scenery it depicts.  The achievement it portrays should be a welcome boost to developing plans to eradicate rodents at other infested islands in the Southern Ocean, notable the United Kingdom’s Gough and South Africa’s Marion, both overrun with predatory House Mice that have taken to killing albatrosses and petrels.

Flying loaded bait pods ashore 

Flying a bait drop, photographs courtesy of Tony Martin

Anthony Martin is Director of the South Georgia Heritage Trust’s Habitat Restoration Project, as well as being Professor of Animal Conservation at the Centre for Remote Environments, University of Dundee in Scotland.  The South Georgia Heritage Trust seeks to undertake projects that will conserve and protect the island’s important natural habitat, such as restoring large areas of habitat that threatened species of birds are unable to use to breed because of the presence of rats introduced some 150 years ago.

Professor Martin has previously published a book on albatrosses; click here for its review in ACAP Latest News.  His latest book, reviewed here, comes with a Forward by HRH The Princess Royal, Patron of the SGHT, who has been a great supporter of the eradication project.

With thanks to Tony Martin.

Reference:

Martin, T. with photographs by members of Team Rat.  undated*.  Reclaiming South Georgia.  The Defeat of Furry Invaders on a Sub-Antarctic Island.  [Dundee]: South Georgia Heritage Trust.  144 pp.  ISBN 978-0-9564546-3-8.  Hardcover, profusely illustrated in colour.  UK£ 25.00.

*Published October 2015.

John Cooper, ACAP Information Officer, 07 April 2016

*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 Ninth Meeting of ACAP’s Advisory Committee, to be held in La Serena, Chile next month, will be preceded by the Seventh Meeting of the AC’s Seabird Bycatch Working Group from 2 to 4 May and the Third Meeting of the AC’s Population and Conservation Status Working Group on 5 and 6 May.

Documents and Information Papers for these two working groups are now available on this website (click here).  Note that some are password protected, with only summaries publically available.

White-phase Southern Giant Petrel scavenging on Bouvet Island, photograph by Greg Hofmeyr

John Cooper, ACAP Information Officer, 06 April 2016