Peter Ryan (FitzPatrick Institute, University of Cape Town, Rondebosch, South Africa) and colleagues have published open access in the journal Marine Ornithology on the increasing breeding population of ACAP-listed and Vulnerable Spectacled Petrels Procellaria conspicillata, as well as information on population sizes of three albatross species breeding on Inaccessible Island.

The paper’s abstract follows:

“Inaccessible Island, in the Tristan da Cunha archipelago, is the sole breeding site of the Spectacled Petrel Procellaria conspicillata.  The island also supports globally important populations of four threatened seabirds, as well as populations of other seabird species.  A seabird monitoring protocol was established in 2004, following baseline surveys of most surface-breeding species in 1999.  For the species monitored, we report population trends that are based on visits in 2009 and 2018.  Populations of most monitored species appear to be stable or increasing, including three albatross species currently listed as Endangered or Critically Endangered.  However, numbers of Northern Rockhopper Penguin Eudyptes moseleyi may have decreased slightly since 1999, and numbers of Antarctic Tern Sterna vittata have decreased since 1982.  The population of Spectacled Petrels is estimated to be at least 30 000 pairs and continues to increase since feral pigs Sus scrofa died out on the island in the early 20th century.  We describe a new monitoring protocol for Spectacled Petrels that will be easier to repeat and implement and that should provide a more sensitive measure of future population changes.”

A Spectacled Petrel calls on Inaccessible Island, photograph by Peter Ryan

Read an earlier ALN post on the 2018 Inaccessible survey.

Reference:

Ryan, P.G., Dilley, B.J. & Ronconi, R.A. 2019. Population trends of Spectacled Petrels Procellaria conspicillata and other seabirds at Inaccessible Island.  Marine Ornithology 47: 257-265.

John Cooper, ACAP Information Officer, 19 October 2019

In 2006/07 and 2007/08 I spent two summers on Gough, a UK island in the South Atlantic, working on alien plant eradications with small teams of volunteers.  As well as this necessary work towards the island’s conservation management, we climbed into Gough’s mountainous interior to the localities where Critically Endangered (and near-endemic) Tristan Albatrosses Diomedea dabbenena breed – and where their downy chicks were being attacked and killed by the island’s introduced House Mice Mus musculus during winter months (click here).  In addition to conducting island-wide censuses of incubating birds, we also set up a long-term monitoring study of Tristan Albatrosses in Gonydale, metal and colour banding incubating adults, which we sexed by bill measurements and plumage, and staking and mapping their nests.  With a 150 or more nests to visit multiple times to record and band partners over both summers of a biennial breeder in a locality that requires a two-hour climb from the South African weather station we needed to overnight on visits using light-weight geodesic tents, back-packing in all our equipment and supplies.

Ever since these two summers a decade ago annual field teams on Gough have continued to climb to Gonydale to follow the fortunes of the colour-banded birds, re-stake nests, record the presence of eggs and band the few chicks that survived the onslaughts of the mice.  Hard, but rewarding work, camping in often cold, wet and windy conditions.

From this coming summer, however, field work will become a little easier by the placement of twin huts in Gonydale during the annual relief of the weather station last month by the South African National Antarctic Programme (SANAP) of the Department of Environment, Forestry and Fisheries.  Ben Dilley, of the University of Cape Town’s FitzPatrick Institute of African Ornithology, modified a second-hand six-metre shipping container into two field huts in Cape Town, fitting both sections with windows, doors, insulation, wooden bunks (two single beds in each hut), tables and a cooking counter served by gas in one hut.  These were shipped to the island on South Africa’s Antarctic research and supply ship, the S.A. Agulhas II and flown into the mountains by helicopter, where they were placed side by side and securely tied down with ropes to counter the island’s often savage winds.

A base for the huts gets prepared in Gonydale, Green Hill (left) and West Rowett behind

From left: Alexis Osborne, Andrew Callender, Chris Jones, Ben Dilley & Michelle Risi

Celebrating completing erection of the Gonydale huts, snow-sprinkled South Rowett behind

Michelle Risi and Chris Jones display their World Albatross Day banner outside the entrance doors of the Gonydale twin huts, photo by Alexis Osborne

A basic interior but beats camping and outside cooking in the snow!

Field researchers Chris Jones, Alexis Osborne & Michelle Risi (in their second consecutive year on the island as members of South Africa’s G65 team) will now be able to overnight in the dry and (relative) warmth while they continue monitoring Gonydale’s Tristan Albatrosses.  If all goes well 2019/20 will be the last season that the albatross chicks will have to face attacks by mice, as next May poison bait will be dropped by helicopter over the whole island in an ambitious attempt to eradicate them.  The huts will also be used when Critically Endangered and endemic Gough Finches Rowettia goughensis are caught to be kept in temporary captivity next year to avoid them being at risk of poisoning along with mice.  A decision is expected to be made on how long the huts should remain in Gonydale after the eradication exercise.

With thanks to Ben Dilley and the FitzPatrick Institute for information and photographs.  The container huts were funded by the UK’s Royal Society for the Protection of Birds (RSPB) as part of the Gough Island Restoration Programme.

Selected References:

Angel, A. & Cooper, J. 2006.  A review of the impacts of introduced rodents on the islands of Tristan da Cunha and Gough.  RSPB Research Report No. 17.  58 pp.

Caravaggi, A., Cuthbert, R.J., Ryan, P.G., Cooper, J. & Bond, A.L. 2018.  The impacts of introduced House Mice on the breeding success of nesting seabirds on Gough Island.  Ibis doi.org/10.1111/ibi.12664.

Cuthbert, R., Sommer, E., Ryan, P.G., Cooper, J. & Hilton, G. 2004. Demography and conservation of the Tristan Albatross Diomedea [exulans] dabbenena. Biological Conservation 117: 471-481.

Davies, D., Dilley, B.J., Bond, A.L., Cuthbert, R.J. & Ryan, P.G. 2015. Trends and tactics of mouse predation on Tristan Albatross Diomedea dabbenena chicks at Gough Island, South Atlantic Ocean. Avian Conservation and Ecology 10 (1): 5. http://dx.doi.org/10.5751/ACE-00738-100105.

Ryan, P.G., Cooper, J. & Glass, J.P. 2001. Population status, breeding biology and conservation of the Tristan Albatross Diomedea [exulans] dabbenena. Bird Conservation International 11: 33-46.

John Cooper, ACAP Information Officer, 18 October 2019

Erica Donnelly-Greenan (Moss Landing Marine Laboratories, Moss Landing, California, USA) and colleagues have published in the Marine Pollution Bulletin on surveys of entangled seabirds on the coast of California.  Sooty Shearwaters Ardenna grisea made up 8%.  A few Arctic or Northern Fulmars Fulmarus glacialis were also reported, as was a Black-footed Albatross Phoebastria nigripes entangled with a balloon.

The paper’s abstract follows:

“Marine fauna in the California Current System is susceptible to entanglement in anthropogenic debris.  We examined beach survey data from six California counties to describe trends of entangled marine birds and mammals (1997–2017). Surveyors reported 357 cases of entanglements among 65,604 carcasses. Monterey County had the greatest average entanglement rate (0.007) of surveyed counties, however, was not statistically different from Santa Cruz (p > 0.05). Twenty-six seabird species (97%) and three marine mammal species (3%), and three non-marine birds were affected. Numerically, Common Murre (23%), Brandt's Cormorant (13%), Western Gull (9.6%), Sooty Shearwater (8%) and Brown Pelican (7%) were the most affected due to abundance, but their entanglement rates were not statistically different (p > 0.05). The most vulnerable species were those frequently documented as entanglement despite low deposition numbers (Merganser spp. 25%). Entangling material consisted primarily of monofilament line (some hooks/lures), but other entanglement items were reported.”

Entangled Black-footed Albatross - from the publication

With thanks to Hannah Nevins.

Reference:

Donnelly-Greenan, E.L., Nevins, H.M. & Harvey, J.T. 2019.  Entangled seabird and marine mammal reports from citizen science surveys from coastal California (1997–2017).  Marine Pollution Bulletin 149: doi.org/10.1016/j.marpolbul.2019.110557.

John Cooper, ACAP Information Officer, 17 October 2019

Davi Tavares (Department of Theoretical Ecology and Modelling, Leibniz Centre for Tropical Marine Research, Bremen, Germany) and colleagues have published open access in the journal Animal Conservation on at-sea mortality of three seabird species based on stranding data, including of the ACAP-listed and globally Endangered Atlantic Yellow‐nosed albatross Thalassarche chlororhynchos.

The paper’s abstract follows:

“Large‐scale climatic processes such as the El Niño‐Southern Oscillation (ENSO) can have severe effects on the survival of seabirds in their breeding regions. However, there is a fundamental lack of understanding about how environmental factors are related to the mortality of these organisms in non‐breeding areas of the tropics. We investigate here the direct and indirect effects of ENSO and oceanographic variables on the mortality of three migratory seabird species targeted by conservation programmes focused on human impacts: the Atlantic yellow‐nosed albatross Thalassarche chlororhynchos, the Magellanic penguin Spheniscus magellanicus and the Manx shearwater Puffinus puffinus in a non‐breeding area in Brazil, tropical Atlantic. We find that the intensification of ENSO increases the mortality of Manx shearwaters by enhancing the local storm activity. The mortality of Atlantic yellow‐nosed albatrosses and Magellanic penguins is also related to a local increase in storm activity but regardless of the ENSO signature. Increased mortality of Magellanic penguins is observed when biological productivity falls below the annual average (1.7 mg m⁻³). Adverse climatic conditions are highly deleterious for migratory seabirds and single storm episodes can cause massive deaths, thus exacerbating population declines. We argue that conservation and management strategies for migratory seabirds studied here should not only focus on direct human impacts but should also consider mitigating the effects of climate variability.”

Juvenile Atlantic Yellow-nosed Albatross washed ashore in Brazil (click here)

Reference:

Tavares, D.C., Moura, J.F., Merico, A. & Siciliano, S, 2019.  Mortality of seabirds migrating across the tropical Atlantic in relation to oceanographic processes.  Animal Conservation doi:10.1111/acv.12539.

John Cooper, ACAP Information Officer, 16 October 2019