Wandering Albatross in flight, artwork by Grace Innemee for ACAP

Eugene Murphy (British Antarctic Survey) and colleagues have published in the journal Frontiers in Ecology and Evolution on the global connectivity of the Southern Ocean in a wide-ranging review.  Mention is made of the active dispersal of seabirds: “during both incubation and chick-rearing, albatrosses and petrels travel long distances during extended foraging trips.  For example, Wandering Albatrosses Diomedea exulans that breed south of the APF [Antarctic Polar Front] … forage in shelf areas off South America and in oceanic waters around the subtropical convergence. Some species breeding on sub-Antarctic islands north of the APF do the opposite, flying south to forage in the Southern Ocean.”

The paper’s abstract follows:

“Southern Ocean ecosystems are globally important. Processes in the Antarctic atmosphere, cryosphere, and the Southern Ocean directly influence global atmospheric and oceanic systems. Southern Ocean biogeochemistry has also been shown to have global importance. In contrast, ocean ecological processes are often seen as largely separate from the rest of the global system. In this paper, we consider the degree of ecological connectivity at different trophic levels, linking Southern Ocean ecosystems with the global ocean, and their importance not only for the regional ecosystem but also the wider Earth system. We also consider the human system connections, including the role of Southern Ocean ecosystems in supporting society, culture, and economy in many nations, influencing public and political views and hence policy. Rather than Southern Ocean ecosystems being defined by barriers at particular oceanic fronts, ecological changes are gradual due to cross-front exchanges involving oceanographic processes and organism movement. Millions of seabirds and hundreds of thousands of cetaceans move north out of polar waters in the austral autumn interacting in food webs across the Southern Hemisphere, and a few species cross the equator. A number of species migrate into the east and west ocean-basin boundary current and continental shelf regions of the major southern continents. Human travel in and out of the Southern Ocean region includes fisheries, tourism, and scientific vessels in all ocean sectors. These operations arise from many nations, particularly in the Northern Hemisphere, and are important in local communities as well as national economic, scientific, and political activities. As a result of the extensive connectivity, future changes in Southern Ocean ecosystems will have consequences throughout the Earth system, affecting ecosystem services with socio-economic impacts throughout the world. The high level of connectivity also means that changes and policy decisions in marine ecosystems outside the Southern Ocean have consequences for ecosystems south of the Antarctic Polar Front. Knowledge of Southern Ocean ecosystems and their global connectivity is critical for interpreting current change, projecting future change impacts, and identifying integrated strategies for conserving and managing both the Southern Ocean and the broader Earth system.”

With thanks to Richard Phillips, British Antarctic Survey.

Reference:

Murphy, E.J., Johnston, N.M., Hofmann, E.E., Phillips, R.A., Jackson, J., Constable, A.J., Henley, S.F., Melbourne-Thomas, J., Trebilco, R., Cavanagh, R.D., Tarling, G.A., Saunders, R.A., Barnes, D.K., Costa, D.P., Corney, S., Fraser, C.L., Höfer, J., Hughes, K.A., Sands, C.J., Thorpe, S.E., Trathan, P. & Xavier, J.C. 2021.  Global connectivity of Southern Ocean ecosystems.  Frontiers in Ecology and Evolution.  doi: 10.3389/fevo.2021.624451.

John Cooper, ACAP Information Officer, 09 August 2021

Location of identified hotspot in the middle of North Atlantic and summary information of species groups at the site (from the publication)

Tammy Davies (BirdLife International, Cambridge, UK.) and many colleagues have published open access in the journal Conservation Letters on identifying a “major hot spot” for 21 seabird species, including 10 procellariiform species of fulmars, petrels and shearwaters, in the North Atlantic, that is recommended for Marine Protected Area status.

The paper’s abstract follows:

“The conservation of migratory marine species, including pelagic seabirds, is challenging because their movements span vast distances frequently beyond national jurisdictions. Here, we aim to identify important aggregations of seabirds in the North Atlantic to inform ongoing regional conservation efforts. Using tracking, phenology, and population data, we mapped the abundance and diversity of 21 seabird species. This revealed a major hotspot associated with a discrete area of the subpolar frontal zone, used annually by 2.9–5 million seabirds from ≥56 colonies in the Atlantic: the first time this magnitude of seabird concentrations has been documented in the high seas. The hotspot is temporally stable and amenable to site-based conservation and is under consideration as a marine protected area by the OSPAR Commission. Protection could help mitigate current and future threats facing species in the area. Overall, our approach provides an exemplar data-driven pathway for future conservation efforts on the high seas.”

Read a popular account of the publication:  "The hot-spot was of particular importance to Great Shearwater [Puffinus gravius], with 1.5 million or more spending the months of April-September there".

Great Shearwater at sea

Reference:

Davies, T.E., Carneiro, A.P.B. et al. 2021.  Multispecies tracking reveals a major seabird hotspot in the North Atlantic. Conservation Letters.  doi.org/10.1111/conl.12824 and supplementary material.

John Cooper, ACAP Information Officer, 06 August 2021

Future assured? A helicopter flies a bait bucket above a Tristan Albatross chick on Gough Island, photograph by Michelle Risi

UPDATE: BAITING COMPLETED!

 “JOB DONE! Baiting on Gough is complete! Now there’s nothing more we can do to increase our chances of eradicating the mice – everyone has given this everything they’ve got!” - Gough Island Restoration Programme (GIRP) Facebook Page.

Full coverage attained! The colours refer to areas baited by the four different helicopters

For those amongst us who have been waiting anxiously to hear, the news has now arrived to much relief.  The Gough Island Restoration Programme (GIRP) announced yesterday on its Facebook Page that the second bait application to eradicate the island’s introduced House Mice was completed on the first of August.  This follows a long gap since the completion of the first bait drop back in June (the usual gap is around two weeks), with poor weather conditions having caused the delay.

“The second bait application on Gough Island is complete!  The team finally got a decent enough break in the weather and managed to finish the second application yesterday.  Whilst the completion of the second drop is significant and means we now have a reasonable chance of the mouse eradication operation being a success, a supplementary application had always been planned over 'high-risk' areas - to ensure we did absolutely everything within our power to eradicate the mice.  The great news is that with two consecutive good days for baiting, most of this supplementary baiting has also been completed!”

It seems South Africa’s Antarctic research and supply ship, the S.A. Agulhas II will arrive at Gough to remove the eradication team around mid August, so there should be ample time to complete the supplementary drops. Here’s hoping that will signal the end of the “killer” mice and allow the island’s albatrosses and petrels to breed unhindered for the first time in decades. In fact, there Already early signs of success with no losses of Tristan Albatross chicks to mice in two study areas after the first bait drop.

Access the latest (No. 9, July 2021) and earlier editions of Island Restoration News, the GIRP newsletter, here.

John Cooper, ACAP Information Officer, 03 August 2021, updated 05 August 2021

Black-winged Petrel

Luke Halpin (School of Biological Sciences, Monash University, Clayton, Victoria, Australia) and colleagues have published in the journal The American Naturalist on endemic giant centipedes preying upon chicks of the Black-winged Petrel Pterodroma nigripennis on Phillip Island, Norfolk Islands, Australia.

The paper’s abstract follows in English and Spanish:

“On isolated islands, large arthropods can play an important functional role in ecosystem dynamics. On the Norfolk Islands group, South Pacific, we monitored the diet and foraging activity of an endemic chilopod, the Phillip Island centipede (Cormocephalus coynei), and used a stable isotope mixing model to estimate dietary proportions. Phillip Island centipede diet is represented by vertebrate animals (48%) and invertebrates (52%), with 30.5% consisting of squamates, including the Lord Howe Island skink (Oligosoma lichenigera) and Günther’s island gecko (Christinus guentheri); 7.9% consisting of black-winged petrel (Pterodroma nigripennis) nestlings; and 9.6% consisting of marine fishes scavenged from regurgitated seabird meals. Centipede predation was the principal source of petrel nestling mortality, with annual rates of predation varying between 11.1% and 19.6% of nestlings. This means that 2,109–3,724 black-winged petrel nestlings may be predated [sic] by centipedes annually. Petrels produce a single offspring per year; therefore, predation of nestlings by centipedes represents total breeding failure for a pair in a given year. Our work demonstrates that arthropods can play a leading role in influencing vertebrate reproductive output and modifying trophic structures and nutrient flow in island ecosystems.

La depredación de artrópodos sobre vertebrados estructura las dinámicas tróficas de ecosistemas insulares

En islas remotas, los artrópodos de gran tamaño pueden jugar un papel funcional importante en la dinámica del ecosistema. En las Islas Norfolk, en el Pacífico sur, monitoreamos la dieta y comportamiento de forrajeo de un quilópodo endémico, el ciempiés de Phillip Island (Cormocephalus coynei), y usamos isótopos estables para estimar la composición de su dieta. La dieta del ciempiés de Phillip Island está representada por animales vertebrados (48%), e invertebrados (52%): con un 30.5%, las especies del orden Squamata como el eslizón de Lord Howe Island (Oligosoma lichenigera) o el gecko de Günther’s Island (Christinus guentheri); un 7.9% pollos de petrel alinegro (Pterodroma nigripennis); y un 9.6% peces obtenidos de los regurgitados de las aves marinas. La depredación por parte de los ciempiés fue la principal causa de mortalidad de los pollos de aves marinas, con tasas de depredación entre el 11.1% y el 19.6%. Considerando el límite superior del tamaño poblacional estimado para el petrel alinegro, los ciempiés podrían estar depredando 2.109–3.724 pollos por año en este ecosistema. Como los petreles producen un solo huevo por año, la depredación del pollo representa el fracaso reproductivo total para una pareja en ese año. Nuestra investigación demuestra que los artrópodos pueden desempeñar un papel central en los ecosistemas insulares, al influir en el éxito reproductivo de vertebrados y modificar las estructuras tróficas y el flujo de nutrientes.”

Read a popular account of the research here, with video of centipede predation.

Reference:

Halpin, L.R., Terrington, D.I., Jones, H.P., Mott, R., Wong, W.W., Dow, D.C., Carlile, N. & Clarke, R.H. 2021.  Arthropod predation of vertebrates structures trophic dynamics in island ecosystems.  The American Naturalist  doi.org/10.1086/715702.

John Cooper, ACAP Information Officer, 05 August 2021