A pair of Sandwich Terns engage in mutual display on the United Kingdom's Farne Islands

Wouter Courtens (Research Institute for Nature and Forest, Brussels, Belgium) and colleagues have published open access in the journal Nature Communications showing that older Sandwich Terns Thalasseus sandvicensis are more likely to succumb to Highly Pathogenetic Avian Influenza (HPAI) than are younger birds. The implications for long-lived ACAP albatrosses and petrels warrant study,  as the following texts taken from their publication attest.

“We show that HPAI-related mortality during the 2022 outbreak in northwestern European Sandwich terns was age-biased, with older individuals disproportionately affected, while mortality was not biased by sex.  This pattern suggests that HPAI did not act as a random mortality source, but selectively removed individuals that likely contribute substantially to population growth. … Seabirds – including penguins, albatrosses, petrels, gannets, gulls, terns and auks – share life-history traits such as delayed maturity, low annual reproductive output, and colonial breeding, making them particularly vulnerable to adult mass mortality events caused by infectious diseases.  The loss of experienced individuals could reduce the reproductive output, delaying recovery, and increase the risk of long-term population declines. … For seabirds already facing multiple pressures, including climate change, overfishing, predation, and habitat loss, the emergence of HPAI adds an additional source of vulnerability in an increasingly unstable world.”

The paper’s abstract follows:

“In recent years, highly pathogenic avian influenza (HPAI) A (H5N1) clade 2.3.4.4b viruses have caused mass mortality events in seabirds worldwide, raising concern for long-lived species with low reproductive rates. Using 28 years of ringing data together with individual-level data from the 2022 mass mortality event in northwestern European Sandwich terns (Thalasseus sandvicensis), we show that mortality was biased towards older individuals, while no sex bias was observed. HPAI-related mortality increased from approximately 5–10% in young breeders to more than 40% in the oldest individuals. This age-biased loss likely removed the most experienced individuals from the population. Our findings highlight a previously underappreciated mechanism through which HPAI outbreaks may impair the resilience of long-lived avian populations.”

Reference:

Courtens, W., Ballmann, M., Fijn, R. et al. 2026.  Avian influenza amplified age-related mortality in a long-lived seabird. Nature Communications 17, 8653 doi.org/10.1038/s41467-026-76726-7.

With thanks to Rob Simmons.

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 25 August 2026

A Northern Giant Petrel chick close to fledging on New Zealand’s Auckland Island, photograph by Colin O'Donnell

Highly Pathogenetic Avia Influenza (HPAI) has been confirmed in a Northern Giant Petrel Macronectes halli from the southeastern corner of New Zealand's North Island.

“A third case of H5 bird flu has been detected in a northern giant petrel, in the Wairarapa.  Ministry for Primary Industries says it was found dead on a remote Cape Palliser beach.  It follows cases found in a kāhu, or swamp harrier, and a brown skua.  It was found by a Department of Conservation (DOC) ranger, who notified the MPI hotline.  Samples received by the MPI Animal Health Laboratory on 14 August were tested and initially found low levels of influenza virus in the bird. It took several rounds of testing to confirm bird flu.”

The New Zealand record is the first for an ACAP-listed seabird.  In Australia at least 17 giant petrels have been found to be infected with HPAI.

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 24 August 2026

Unconcerned: Michelle Risi pauses while reading colour bands next to an incubating Southern Giant Petrel in the Low Hump colony on Gough Island, photograph by Chris Jones

I am sometimes asked “Which is your favourite among the 31 ACAP-listed seabirds?”  My answer might surprise, for it is not the iconic Wandering Albatross Diomedea exulans of Marion Island or the equally iconic Tristan Albatross D. dabbenena of Gough Island, both of which I have studied.  No, my co-favourites are the two giant petrels, the Northern M. halli and the Southern M. giganteus, which I have also studied on Marion (both species) and Gough (Southern) Islands. With my last island visits now over a decade ago, I am pleased that the data collected from the long-term studies of colour-banded Northerns on Marion and Southerns on Gough that I set up years back will now contribute to a PhD study by ACAP supporter, Michelle Risi – who has worked with both species in the field on Marion and Gough.  She is based in the FitzPatrick Institute of African Ornithology at the University of Cape Town, where I worked for several decades last century.

Michelle Risi writes to ACAP Latest News: “I hold an MSc in Biology from the University of KwaZulu-Natal (2015), along with BSc Honours and BSc degrees, both awarded cum laude.  Over the past decade, I have dedicated my career to wildlife conservation, with a particular focus on long-term seabird monitoring and the restoration of remote island ecosystems for threatened species.  For the past seven years, I have worked extensively on the demographic datasets for giant petrels from Gough and Marion Islands.  This has included compiling, cleaning and curating long-term monitoring data, as well as standardising records for mark-recapture and breeding success analyses.  My familiarity with these datasets and the colonies they represent provides me with a unique advantage, allowing me to conduct the planned analyses efficiently and produce high-quality outputs for my PhD thesis.”

Michelle guiding aboard the Roald Amundsen along the Antarctic Peninsula in summer 2025/26

A summary of Michelle’s PhD project, entitled “Understanding the drivers of seabird demography in a changing ocean: insights from long-term studies of giant petrels”, follows:

“Global climate change and human activities are transforming marine ecosystems, yet the impacts on long-lived apex predators remain poorly understood.  Seabirds, such as giant petrels Macronectes spp., are key indicators of ocean health, integrating ecological change across broad spatial and temporal scales. Northern (NGP, M. halli) and Southern Giant Petrels (SGP, M. giganteus) are large, long-lived seabirds with circumpolar distributions in the Southern Hemisphere, breeding mostly at scattered sub-Antarctic and Antarctic islands.  Males play critical ecological roles as both predators and scavengers, occupying the top of the marine food web and making them especially sensitive to ecosystem changes.  Females have a more pelagic distribution, ranging as far from their colonies as albatrosses, and consume a diverse diet that includes fish, crustaceans, squid and carrion.  Both sexes commonly scavenge behind fishing vessels and are bycaught in various longline and trawl fisheries across the Southern Ocean.  Giant petrel nestlings are impacted by heat stress, and nesting adults have also been recorded being attacked by House Mice Mus musculus on Marion Island, leading to nest abandonment.

A previous study of adult survival at Bird Island, South Georgia (Islas Georgias del Sur)*, showed that sex-specific ecological differences can lead to divergent responses to environmental drivers.  For example, females were more likely to be impacted by changes in pelagic longline effort.  However, that study did not assess how changing oceanographic conditions influence other critical demographic parameters, such as breeding probability and success.  Even less is known about the demographic drivers of populations at other sites.  As scavengers, giant petrels are at risk of secondary poisoning during rodent eradication operations, as they may forage on the carcasses of other scavenging birds.  Gough Island had a failed mouse-eradication attempt in 2021, and a mouse eradication operation is planned for Marion Island in 2029 by the Mouse-Free Marion Project.  On Macquarie Island, now free of invasive mammals, the aerial eradication campaign conducted between 2010 and 2011 had a substantial immediate impact on giant petrels, resulting in the deaths of up to 1400 NGPs over two years and an estimated 33% decline in breeding pairs.  Rodent eradication operations are generally undertaken during winter, when most seabirds are foraging at sea, and natural food availability for mice is lowest, thereby maximising bait uptake while reducing potential impacts on non-target species.  It is therefore important to establish a baseline for the number of giant petrels that remain on Marion Island during winter.

Long-term demographic datasets are available from seven Southern Ocean island groups: Signy Island in the South Orkney Islands, Bird Island at South Georgia (Islas Georgias del Sur)*, Gough Island, Marion Island in the Prince Edward Islands, Île de la Possession in the Crozet Archipelago, the Kerguelen Archipelago and Macquarie Island. These datasets include annual counts of breeding birds and fledged chicks, intensive monitoring of individual breeding attempts and, at four sites, capture-mark-recapture records that follow marked birds through their breeding histories.  Together, the sites span broad geographical, oceanographic and management gradients.  Marion Island will serve as the focal system for identifying environmental drivers of breeding success and other demographic parameters, after which the transferability of the results to other giant petrel colonies will be tested.

By analysing long-term demographic data from these breeding sites, the study will explore relationships between vital rates (adult and juvenile survival, breeding frequency, and breeding success) and potential oceanographic drivers (e.g. sea surface temperature, marine productivity, wind regimes).  This will provide a step change in our understanding of how these key predators respond to climate variability and other anthropogenic pressures, while also identifying implications for seabird monitoring and conservation management.

Research Questions:

1.  How have breeding population size and breeding success of Northern and Southern Giant Petrels at Marion Island changed over time, and what is the relative importance of local weather and breeding-season oceanographic conditions on breeding success?
2.  How does winter attendance by giant petrels vary on Marion Island, and is attendance associated with previous breeding outcome and subsequent breeding probability or success?
3.  How transferable are the environmental variables identified as the best predictors of giant petrel breeding success at Marion Island to other populations across the Southern Ocean?
4.  How does environmental variability influence survival, recruitment and breeding probability in giant petrels?

Methods and Impact:

Using long-term breeding counts, nest-monitoring records, winter surveys, capture-mark-recapture data and remotely sensed environmental information, the study will investigate demographic variation at both colony and individual levels.  Winter surveys will be used to determine which giant petrels attend Marion Island during the non-breeding period, whether winter attendance is associated with previous breeding outcome and subsequent breeding probability or success, and what proportion of breeding birds may be exposed during the planned winter mouse-eradication operation.  Analyses will test whether environmental relationships identified at Marion Island are transferable to other colonies.  Multi-event capture-mark-recapture analyses will then assess whether selected environmental variables explain variation in survival, recruitment and breeding probability.  The study will identify the factors associated with demographic change and provide evidence to support ACAP monitoring and conservation management.”

A Northern Giant Petrel on Marion Island eyes the camera, photograph by Michelle Risi

Michelle’s study will be supervised by Associate Professor Susan Cunningham (FitzPatrick Institute), Dr Steffen Oppel (Swiss Ornithological Institute), Professor Richard Phillips (British Antarctic Survey) and Emeritus Professor Peter Ryan (FitzPatrick Institute).

Back in 2019, Michelle proposed to me that there should be a World Albatross Day.  Although I was initially somewhat reluctant, we submitted an Information Paper proposing the day to the ACAP Advisory Committee’s 11th Meeting, held in Brazil the same year.  With the committee’s approval, ACAP marked the first World Albatross Day on 19 June 2020 under the theme of “Eradicating Island Pests”.  Michelle played a significant role in supporting the first “WAD” years by producing a series of photo posters, as well as entering a cake for the “Great Albicake Bake Off” competition in 2020 (click here).  Surely, now that there have been seven successful World Albatross Days held, it is past time for the two ACAP-listed giant petrels to be recognized as “honorary albatrosses” and included in the celebrations for WAD2027.

Husband and wife team, Chris Jones and Michelle Risi, sail from Cape Town for a year on Gough Island aboard the S.A. Agulhas II in September 2024

Michelle and her husband Chris Jones have recently started staying with me in my home near the university for a couple of nights every other week to make their commute from their own home a distance away to campus easier.  Our dinner-table conversations often turn to Gough and Marion, their albatrosses and petrels, and stories from our respective times working with these special birds.  It will then be a pleasure to hear from time to time from Michelle how her PhD work is progressing, and I look forward to reading the peer-reviewed publications that will ensue.

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 21 August 2026

* A dispute exists between the Governments of Argentina and the United Kingdom of Great Britain and Northern Ireland concerning sovereignty of the Falkland Islands (Islas Malvinas), South Georgia and the South Sandwich Islands (Islas Georgias del Sur e Islas Sandwich del Sur) and the surrounding maritime areas.

Antipodean Albatross chick on Pitt Island in 2024, photograph from the Flowerpot Lodge

The New Zealand Department of Conservation has announced funding towards eradicating feral cats and controlling feral pigs on Pitt Island (Rangihaute/ Rangiauria) in the Chatham Islands.

The “Chatham Islands Landscape Restoration Trust will receive [NZ]$1,169,900 for a project to remove feral cats from Rangihaute Pitt Island.  This will protect at least 14 threatened bird species, including the Endangered Shore Plover Thinornis novaeseelandiae (tūturuatu/tchūriwat) and restore several critical ecosystems.”

“The Chatham Islands Farmers Association will receive [NZ]$543,240 to undertake pig control, reducing the impact on threatened species and critically endangered ecosystems, as well.  This work will begin on Rangihaute Pitt Island before commencing on the main Rēkohu Wharekauri Chatham Island.”

A single pair of Endangered Antipodean Albatrosses Diomedea antipodensis breeds on Pitt Island and the Vulnerable Chatham Islands Petrel Pterodroma axillaris breeds in small numbers protected by a fence.

“The last seven unsterilised pet cats on Pitt Island have been flown to neighbouring Chatham Island to be desexed, a crucial step towards eradicating feral predators.”

Pet cats living on Pitt Island have now all been sterilized (click here).

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 20 August 2026