Ground bait station sites on St Agnes and connected Gugh Islands during the rodent eradication operation

St Agnes is one five inhabited islands in the United Kingdom’s Isles of Scilly.  Following the eradication of Norway Rats Rattus norvegicus by a ground-baiting campaign a decade ago, both Manx Shearwaters Puffinus puffinus and European Storm Petrels Hydrobates pelagicus have been recorded breeding, signalling a successful operation (click here).  But this is not the end of the story.  It is necessary to put and keep in place best-practice biosecurity measures at points of entry that will greatly reduce the risk of reintroductions – and continue to keep a look out for signs of rodents elsewhere on the island.  A recent report from St Agnes nicely illustrates the problem as repeated here.

Manx Shearwater chick at its burrow entrance on St Agnes, photograph by Jaclyn Pearson

“Conservationists on an island 28 miles off the UK mainland are concerned after signs there may may be a mouse there, potentially putting a colony of seabirds at risk.  Mice and rats have been eradicated from St Agnes in the Isles of Scilly, as part of measures to protect its nationally significant population of storm petrels.  The Isles of Scilly Wildlife Trust said “probable” signs of a mouse including droppings and urine had been spotted, and suspects the creature was brought in within some animal feed.

The trust has been running a successful program with the RSPB and others to get rid of rodents on the islands for the past decade, which has led to the petrel population "bouncing back.  Tony Whitehead, from the RSPB, said it had a "very well worked out response" which involved putting rodent poison in traps across the island and "then keep checking the traps".

He said if "mice do get a hold on the island" they would be likely to eat the eggs of birds like storms petrels and Manx shearwaters, putting populations at risk. Mr Whitehead said a member of the community had spotted the mouse droppings last Thursday.

The residents of the island have been brilliant and hugely supportive.  The wildlife trust said signs had been put up across St Agnes to warn parents of young children and dog owners about traps.”

Read earlier  articles in ACAP Latest News on the rat eradication operation on the Isles of Scilly.

With thanks to Anton Wolfaardt, Mouse-Free Marion Project.

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

“"When three-people-are-needed-to-get-a-Black Petrel-out-of-a-burrow”, photograph from the article by Elizabeth Bell

Elizabeth Bell (Wildlife Management International Ltd, Blenheim, New Zealand has written on the Vulnerable and ACAP-listed Black Petrels Procellaria parkinsoni that breed on Aotea/Great Barrier Island in the online oublication, Pacific Seabirds.  She writes “WMIL has been working at the main colony around the summit Hirakimata/Mt Hobson, monitoring 482 study burrows within the 35-ha study site each breeding season.  This work can involve incredible gymnastics, putting one arm down into a burrow while trying not to slide down banks, lying over and under trees or rocks and being very tolerant of painful bites and scratches.”

A Black Petrel pair, photograph by Elizabeth Bell

“During the 2023/24 breeding season, 63.5% of the study burrows were occupied by breeding pairs, 12% occupied by non-breeding birds, and 24.5% were unoccupied during our visits (with over 50% of those unoccupied burrows showing no evidence of activity at all, i.e., blocked up, no feathers, scent of guano, etc.).  Overall, 222 chicks were produced from the study burrows representing a fledgling success rate of 72.5%.”

Read more about the study in her illustrated article.

Reference:

Bell, E.  2024.  Tākoketai/Black Petrels (Procellaria parkinsoni) on Aotea/Great Barrier Island, Aotearoa New Zealand.  Pacific Seabirds 51(2).

07 November 2024

The Critically Endangered Newell’s Shearwater Puffinus newelli, one of the species featured in the publication, photograph by Lindsay Young

David Ainley (HT Harvey & Associates, Los Gatos, California, USA) and colleagues have published in the open-access journal Marine Ornithology on ‘floating’ adult seabirds that are able to breed but choose not to.  “Floaters are individuals in a population that are physiologically mature and able to breed but do not because they lack suitable breeding habitat, lack mates, or are dissuaded by the presence of predators.”

The paper’s abstract follows:

“'Floating' portions of seabird populations (mature but non-breeding individuals) are generally ignored in seabird research and management despite frequent evidence of their existence, especially in cavity-nesting species for whom nest habitat is often limiting. Here we demonstrate, using a few among an appreciable number of cases, that often more adults contribute to regional populations than colony-based censuses reveal, and that these birds are able to breed but do not. Once given the chance through the creation of nesting habitat, either by natural or human-caused processes, these populations reveal themselves by occupying the newly created habitats to become breeders. We include a brief discussion of the degree to which natal philopatry contributes to relatively sudden colony establishment. Not recognizing the existence of floating populations due to exclusively colony-based management, which is often politically necessary (e.g., Wildlife Refuge management), hinders conservation because it ignores the source and role of potential immigrants. Instead, management tends to emphasize supposed natal philopatry. Floaters will exploit mortality-caused vacancies in a breeding population, masking temporal variation in adult mortality, falsely indicating colony-size stability as a measure of the ‘health' or resilience of a colony/habitat. In addition, the most successful efforts at establishing new colonies or restoring others by ‘social attraction' are those in which a floating population is present, although unrecognized until it is revealed by the social attraction ‘experiment.' Success comes when the artificially established breeding aggregation becomes an attractant to ‘floaters.' Thus, recruitment of these floaters (especially on a predator-free colony or island) accelerates the limited growth provided by the return of hand-raised translocated nestlings. A lack of appreciation for the presence of floaters also limits the validity of assessments of the impact of bird wrecks and the ability of populations."

Reference:

Ainley, D.G., Divoky, G.J., Baird, P. & Spencer, G.C. 2024.  ‘Floating populations’ of seabirds: the bane of demographic modelers and managers.  Marine Ornithology 52: 379-386.

06 November 2024

 
Patricia Serafini presents her talk “Biochemical and molecular biomarkers in Manx Shearwaters Puffinus puffinus and associations to marine pollution” at the 16th International Seabird Conference in Coimbra, Portugal in September 2024

Patricia Pereira Serafini is a Brazilian wildlife veterinarian specializing in ecology and conservation, particularly focusing on albatrosses, petrels and other seabirds.  She is also Co-convenor of ACAP’s Population and Conservation Status Working Group (PaCSWG).

Patricia is an environmental analyst at the National Center for Research and Conservation of Wild Birds (CEMAVE/ICMBio/Ministry of Environment), in Brazil.  Her expertise lies in a One Health approach to the conservation crisis facing pelagic seabirds, and her research involves population monitoring, molecular biology, biochemistry, ecotoxicology and epidemiology.  Currently she is on a study visit to the United Kingdom and has spent the last few months based at the Department of Biology, University of Oxford, with fieldwork conducted on Manx Shearwaters Puffinus puffinus on the three United Kingdom islands of Skomer, Wales, Lighthouse (Copeland Bird Observatory), Northern Ireland, and Rum, Scotland.

 
Manx Shearwater at night in the biggest colony in the world on the island of Skomer. Wales, UK, photograph during field work by Patricia Serafini

Patricia is currently undertaking PhD research at the Universidade Federal de Santa Catarina (UFSC) in southern Brazil, investigating the health impact of ocean pollution on albatrosses and petrels, using mostly a molecular approach.  She writes:

“My PhD research focuses on assessing how environmental impacts affect pelagic seabirds at biochemical and molecular levels. Through research collaborations with the University of Oxford and the British Antarctic Survey, our work bridges important research institutions across continents.  The study addresses a critical gap in our understanding of ocean pollution's impact on pelagic seabirds.  Although plastic ingestion and pollutants are frequently detected in albatrosses and petrels, the mere presence of contaminants doesn't necessarily indicate immediate threats to their health and survival.  Population-level impacts from chronic pollution may take years to become detectable, highlighting the importance of understanding sublethal effects.

“Using Manx Shearwaters as a model procellariiform species, so far we have analysed 155 liver samples from seabirds stranded along Brazilian beaches.  The study revealed significant associations between specific pollutants and sub-lethal responses:

Organochlorine pesticides (particularly Mirex and Drins) showed significant associations with biotransformation enzymatic activity
Polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) demonstrated notable impacts on classical ecotoxicological molecular biomarkers
Higher levels of certain pollutants appear to suppress rather than stimulate biotransformation gene transcription
HCB showed potential endocrine-disrupting effects at a molecular level
Interestingly, no consistent correlation was found between plastic ingestion and the selected ecotoxicological biomarkers for Manx Shearwaters.”

More information is available in the published first chapter of Patricia’s thesis.

Patricia continues: “My research is now advancing into an exciting new phase focusing on two ACAP-listed species, the Wandering Albatross Diomedea exulans and Atlantic Yellow-nosed Albatross Thalassarche chlororhynchos.  Through a collaboration with the British Antarctic Survey, Instituto Chico Mendes de Conservação da Biodiversidade (ICMBio) and Instituto Tecnológico Vale (ITV), high-quality, chromosome-level genome sequencing and liver transcriptome data have been obtained for both species.  Our current work focuses on completing the genome/transcriptome assembly and annotation for these remarkable seabirds.  This groundbreaking genetic work aims to understand better these magnificent seabirds’ phenotypic plasticity, responses to xenobiotics and immunity under anthropogenic pressure.  The project is scheduled for completion in 2026.”

All smiles at the 11th Meeting of the ACAP Advisory Committee, May 2019.  From left Tatiana Neves, Advisory Committee Vice Chair, John Cooper, ACAP Emeritus Information Officer and Patricia Serafini

Patricia concludes that her PhD research demonstrates the value of seabirds as indicators of marine pollution and will provide new tools for detecting sublethal impacts before they manifest at population levels.  These early indicators could prove crucial for informing timely management decisions to protect these remarkable species.

The Black-browed Albatross is a regular visitor to the waters of Brazil

On a more personal note I have met Patricia at several ACAP meetings, the last in 2019 in her home country when she most ably co-hosted the 11th Meeting of the ACAP Advisory Committee.  She has also willingly and efficiently provided Portuguese texts for an ongoing series of ACAP Species Infographics for the six ACAP-listed albatrosses and petrels that regularly visit Brazilian waters.  It remains a pleasure to continue to work with her!

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 05 November 2024