The silhouette of a White-chinned Petrel returning to its burrow at dusk; photograph by Kalinka Rexer-Huber

Falklands Conservation, with the help of volunteers, recently completed burrowing seabird surveys at two of Stanley's tussac islands over the 2023/2024 breeding season. 

The aim of the work is to inform the review of the Falkland Island Government’s Stanley Tussac Islands Management Plan 2018-2023. This will be done by establishing baseline estimates of population sizes of the Near-Threatened Sooty Shearwater Ardenna grisea and the Vulnerable White-chinned Petrel Procellaria aequinoctialis at these sites, and to assess population trends where previous data exists. This season, fieldwork involved assessing burrow density and occupancy rate of the two species on Kidney and Top islands. Monitoring of Bottom and Cochon islands is planned to take place over the 2024/2025 breeding season.

The survey was covered in a story by the national television broadcaster, Falkland Islands Television (FITV)

Falkland Conservation’s Seabird Ecologist, Amanda Kuepfer, led the survey and explained why the work is so important: “These islands represent nationally important breeding sites for these species - Kidney is the largest breeding colony of sooties [Sooty Shearwaters] in the Falklands, and Kidney, Top and Bottom islands represent three of the four known breeding sites for white-chins [White-chinned Petrels] in the Falklands. Given pressures such as from changing climate, predation from invasives and fisheries bycatch, there is a real risk of local extinction of white-chins in the Falklands, and so understanding population trends at these sites is critical.”

The tussoc-covered landscape of Kidney Island, where Sooty Shearwaters and White-chinned Petrels make their burrows; photograph by Sarah Crofts

Future surveys could involve the help of a detection dog trained to undertake burrowing seabird monitoring work, potentially making this notoriously difficult work a little easier. Falklands Conservation are currently liaising with 2023 ACAP Secondee, Naomi Cordeiro of South Atlantic Detection Dogs, to see what the most effective use of detection dogs with monitoring petrels might be with Naomi and detection dog in training, Missy, joined a survey in December last year to help understand how the use of a detection dog might fit with future monitoring. 

Falklands Conservation are now in the process of analysing the data from this year’s surveys and hope to be able to share the results in July. 

15 April 2024

 Figure 1 from the paper: Study area showing the main ocean currents (a), and seabird records made by season on top of the 1°latitude 1°longitude grid cells (b). In (a), the East Australian Current (EAC) system is highlighted with its acronyms in bold and drawn in blue. The South Equatorial Current (SEC) and its branches, the North Caledonian Jet (NCJ) and South Caledonian Jet (SCJ), are drawn in red. The EAC ’eastern extension’ is an eddy field (blue shaded area) often called the ’Tasman Front’, from which the East Auckland Current originates (EAUC, in green).

Nicholas W. Daudt (Department of Marine Science, University of Otago, Aotearoa, New Zealand) and colleagues have published open access in the journal Progress in Oceanography on the identification of two distinct seabird assemblages and their susceptibility to changing environmental conditions.

The paper’s abstract follows:

“Identifying species assemblages helps understand the relationship between organisms and their environment. Assemblages can be used to predict biological changes caused by environmental perturbations, and are thus essential surrogates to monitor biodiversity. In this study, to identify and describe seabird assemblages, we used 15 at-sea ship-based survey data sets collected over 37°of latitude off eastern Australia, from 2016 to 2021. We fitted seasonal Region of Common Profile (RCP) mixture models, for two types of data (presence–absence and abundance). RCP groups are defined as regions where the probability of encountering a particular species profile is constant within regions, but different amongst them. These groups also vary according to covariates, which in our case included oceanographic, climatic, and physiographic parameters. Results were based on 142,646 seabirds recorded from 80 species, including albatrosses, petrels, prions, shearwaters, boobies, and terns, among other taxa. All models suggested two macro-scale assemblages (‘northern’ and ‘southern’), except for the autumn presence–absence model that identified three groups. The model results consistently show a biogeographic transition at 34°S, near the latitude at which the East Australian Current (EAC) separates from the Australian continental slope. Sea surface temperatures or sea surface salinities were selected in all final models, further indicating a close relationship between seabird assemblages and water masses. Results from both data types, presence–absence and abundance, resulted in similar spatial and species profile patterns. RCP models clearly identified two seabird assemblages off the east coast of Australia, suggesting the persistence of these groups at seasonal and macro spatial scales. Given the ongoing poleward intensification that the EAC is experiencing, which is projected to continue over the next century, and its importance in influencing the distributions of seabirds, the methods applied in our study could be replicated to assess possible changes in seabird assemblages and how they are affected by changing environmental conditions.”

Reference:

Daudt, N.W., Woehler, E. J., Schofield, M. R., Smith, R. O., Bugoni, L., Rayment, W. J. 2024. Seabird assemblages are linked to the major western boundary current off eastern Australia. Progress in Oceanography. Vol. 23. https://doi.org/10.1016/j.pocean.2024.103215

12 April 2024

A badly wounded Grey-headed Albatross chick that will not survive the onslaught by Marion Island’s House Mice, 17 March 2024

UPDATE: On a return visit to the study colony on 08 April, the wounded Grey-headed Albatross, illustrated above, was found to be still alive with its wounds healing.  However, it wings were drooping and it was noticeably smaller than were surrounding chicks that have not been attacked by mice.  So its survival to fledging is not assured.  The other wounded chick seen on 17 March in the same study colony had not survived.

The wounded Grey-headed Albatross chick shows signs of healing, 08 April 2024

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Attacks by introduced House Mice Mus musculus on Marion Island’s albatrosses were first recorded in 2003 – and have continued every breeding season when checks have been made.  First observed on downy chicks, in recent years depredations by the mice have commenced on adult birds incubating or brooding chicks.  Last year’s report of the first observations of adult Wandering Albatrosses Diomedea exulans succumbing to attacks by mice was a further wake-up call, given the bird’s Vulnerable conservation status and that Marion supports a quarter of the world’s population of this iconic species.  Also, the loss of an adult of a long-lived and slow breeding species such as an albatross is far more of a conservation concern than is the loss of a chick.  And now it seems the current 2023/24 breeding season will give no respite to the island’s four species of breeding albatrosses.

This season, mouse attacks have commenced again on Marion’s eponymously named Grey-headed Albatross Ridge.  On 17 March, island researcher Michelle Risi came across the severely wounded Grey-headed Albatross Thalassarche chrysostoma chick pictured above on a marked nest in one of the big colony’s long-term study clusters of breeding birds.  This, and another wounded chick seen on the same day, are the first mouse attacks recorded on this Endangered albatross in the current breeding season.  The chick had been videoed in full health a few days previously on 27 February.  The next nest check comes in April, but the chick is not expected to survive.  Eight chick carcasses were also counted at the time, all showing signs of having been scavenged by mice, which, in all likelihood, had commenced feeding on them while they were still alive, leading to their deaths.

Mouse attack!  A Wandering Albatross with a fresh wound continues to tend its chick, 28 March 2024

The mouse slaughter has not stopped with the Grey-headed Albatrosses.  On 28 March, Michelle was in the north of the island near Cape Davis conducting nest checks on Wandering Albatrosses when she came across and photographed a wounded male bird brooding its downy chick.  Fortunately (so far) the chick had not been attacked by mice.  The locality was not that far from where the dead adult Wanderers had been seen in April last year.  Whereas the brooding bird will be relieved by its partner, and if still alive, have an opportunity to recover and heal at sea, it seems likely the breeding attempt will fail, even if the adult escapes death.

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  The brooding Wandering Albatross displays its wound, 28 March 2024; all photographs by Michelle Risi

The Mouse-Free Marion Project is working towards seeing the end of the island’s mouse plague.

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels & Michelle Risi, Marine Apex Predator Research Unit, Nelson Mandela University, Gqeberha, South Africa, 04 April 2024, updated 11 April 2014

The latest ACAP Species Infographic to be released, the fifteenth in the planned 31-part series, is for the Vulnerable Short-tailed Albatross Phoebastria albatrus.  Following its release in English last month, it is now being released in the other two official ACAP languages of French and Spanish.  A Japanese* version is to follow soon, marking the fact that the majority of the species breeds on Japan’s Torishima.  All four language versions of the Short-tailed Albatross infographic have been sponsored by the Yamashina Institute for Ornithology.

The Short-tailed Albatross infographic, along with the next in the series, for the Near Threatened Buller’s Albatross Thalassarche bulleri, currently in production, are being produced in support of this year’s World Albatross Day on 19 June (WAD2024) and its theme of “Marine Protected Areas – Safeguarding our Oceans”.

The ACAP Species Infographic series has been designed to help inform the public, including school learners, of the threats faced by albatrosses and petrels and what is being and can be done to combat them.  They serve to complement the more detailed and referenced ACAP Species Assessments, the concise and illustrated ACAP Species Summaries and the ACAP Photo Essay series.  English and Portuguese** language versions of the infographics produced to date are available to download here.  French and Spanish versions can be found in their respective language menus for the website under Infographies sur les espèces and Infographía sobres las especies.

All the 15 infographics produced to date may be freely downloaded at a high resolution to allow for printing professionally in two poster sizes (approximately A2 and A3).  Please note they are only being made available for personal use or when engaging in activities that will aid in drawing attention to the conservation crisis faced by the world’s albatrosses and petrels – when ACAP will be pleased to receive a mention.  They should not be used for personal gain.

The ACAP Species Infographics have all been created by Thai illustrator Namasri ‘Namo’ Niumim from Bangkok.  Namo is a graduate of the School of Architecture and Design, King Mongkut’s University of Technology Thonburi with a Bachelor of Fine Arts in Communication Design.

With thanks to ‘Pep’ Arcos, Maëlle Connan, Yasuko Suzuki and Naoki Tomita for their help.

*Japanese versions of the infographics for Black-footed P. nigripes and Laysan P. immutabilis Albatrosses, both of which breed on Japanese islands, are also in production.

**Being produced for the six ACAP-listed species that regularly visit waters off Brazil.  To date, those produced are for the Tristan Albatross D. dabbenena and the Black-browed Albatross Thalassarche melanophris.

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 11 April 2024