A Southern Giant Petrel sits alongside its two chicks in the nest; photograph by Júlia Finger

Chilean seabird ecologist Júlia Finger has provided ACAP Latest News with an account of a rare sighting of two two-egg Southern Giant Petrel clutches spotted at Harmony Point, Nelson Island in maritime Antarctica. The clutches were observed whilst Julia and fellow team members were conducting fieldwork for a Chilean Antarctic Institute (INACH) project in the austral summer of 2022.

When asked about her reaction to the discovery Júlia stated, "I've been working with giant petrels for the last 10 years, so it was a huge surprise to see two-egg clutches for the first time after all these years. But if there's one thing that giant petrels can do well is to surprise us with novel behaviours (which later I found iweren't that novel)! The team was excited with the unusual find and also happy to see that the two chicks looked healthy and well-nourished. We could only hope for a two-chick fledge!"

Her official record states in translation: 

On 23 January 2022 we first observed two Southern Giant Petrel Macronectes giganteus nests with two-egg clutches at Harmony Point, Nelson Island (maritime Antarctica). One nest had two chicks about two weeks old. One was younger than the other and was being guarded underneath the body of the male. The other was lying beside the adult. Chicks had similar body size to other chicks at the area. The other nest had two eggs, but we believe at least one was spoiled because it had a crack. Also, hatching was two weeks overdue. As we were about to leave the area a few days later, we did not check if the pair were able to successfully raise two chicks until fledging.

Two-egg clutches are rare for the species. In 1962, John Warham described the frequency of occurrence to be 0.14 to 0.18% (4 - 5) of all nests at Macquarie Island.  Harmony Point holds a population of ca 480 nests, and after checking all nests from a distance, we assume the frequency of two-egg clutches in this population to be at least 0.41%. Warham also states that the birds were capable of covering both eggs during incubation.  However, he wasn't able to confirm if the brood patch covered both eggs. Nevertheless, three of the nests Warham found did not hatch and in the other two nests that did, neither of the pairs succeeded in rearing both chicks. Other sites with records of two-egg clutches of Southern Giant Petrels are Îles des Pétrels in Terre-Adélie, Antarctica  (Prévost 1953), where one nest among 120 was found to have two eggs; and Anvers Island, Western Antarctic Peninsula, where five nests were recorded (Shaughnessy 2017).

The second Southern Giant Petrel clutch containing two eggs; photograph by Júlia Finger

Two-egg clutches are also known to occur among albatrosses, with ACAP covering an account from Chris Jones and Michelle Risi of an Atlantic Yellow-nosed Albatross pair with a two-egg clutch on Gough Island in 2015. 

With thanks to Júlia Finger for translating her account.

REFERENCES:

Ryan, P.G., Cuthbert, R. & Cooper, J. 2007.  Two-egg clutches among albatrosses. Emu 107: 210-213.

Warham, J. 1962. The biology of the Giant Petrel Macronectes giganteus.  Auk 79: 139-160.

Prévost J. 1953. Note sur l'écologie des pétrels de Terre Adélie. Alauda 21: 205-222.

Shaughnessy, P.D. 2017. A two-egg clutch or polygyny?  Two white-phase chicks in the nest of a Southern Giant Petrel Macronectes giganteus at Macquarie Island. Marine Ornithology 45: 43-46. [click here for ACAP review]

2 November 2022

A Flesh-footed Shearwater at sea; photograph by Kirk Zufelt

NOTE:  ACAP Monthly Missives are more personal than those news articles that are regularly posted in ACAP Latest News.  The new series offers the opportunity to go behind and beyond factual events and current news, giving opinions on matters related to the conservation of all the members of the tubenose group of birds.  Posts will be largely written by the Emeritus ACAP Information Officer, with guests from time to time invited to make their own contributions.  This missive is the second in the series, the first reviewed the connection between the United Kingdom Royal Family and albatrosses.  The opinions expressed in ACAP Monthly Missives are not to be taken as those of the ACAP Secretariat or any of the Agreement’s Parties.

*******************************************

Shearwaters in the genera Ardenna, Calonectris and Puffinus are pursuit divers known to be killed by longline fisheries.  Longline mortality of albatrosses and petrels directly led to the negotiation and adoption of the Agreement in 2001 but at the time shearwaters were not considered for listing.  Following a 2008 published review of procellariiform species that identified several shearwaters for possible listing via a scoring system, two shearwaters have been included within the Agreement, the Critically Endangered Balearic Puffinus mauretanicus in 2012 and the Vulnerable Pink-footed Ardenna creatopus in 2015.  Subsequently, the original list of candidate species has been reviewed by ACAP, with the most recent text available in MoP7 Inf 02, and the next review scheduled for the Thirteenth Meeting of the ACAP Advisory Committee (AC13) and its working groups in May 2023.

ACAP-listed Balearic (left) and Pink-footed (right) Shearwaters; photographs by ‘Pep’ Arcos and Peter Hodum

The question arises, should more shearwater species be added to the Agreement?  Here, I consider whether two species that have been identified with high weighted totals in the latest review should be listed, what activities have taken place to date towards their nomination, what might be the consequences of and impediments to their listing, and a way forward.

Flesh-footed Shearwater

At the Eleventh Meeting of ACAP’s Advisory Committee (AC11), held in Brazil in 2019, New Zealand reported it was considering the merit of nominating the globally Near Threatened Flesh-footed Shearwater Ardenna carneipes for listing by ACAP (click here).  Flesh-footed Shearwaters are regularly caught as bycatch by commercial fisheries in both Australian and New Zealand waters.  The species is also known for the ingestion of large amounts of plastic fragments, at least at some breeding localities, notably Australia’s Lord Howe Island, as a series of papers by the University of Tasmania’s Adrift Lab continues to show.  The Flesh-footed Shearwater (categorized as Nationally Vulnerable by New Zealand and as Vulnerable by New South Wales and Western Australia, but not categorized by the Australian Federal Government) has been previously identified as a potential candidate species for such listing (see AC11 Inf 04).  Perhaps due to COVID-19 resulting in recent meetings of the Agreement being shortened versions held virtually, there appears to have been little progress in the last three years with its nomination.

The Flesh-footed Shearwater breeds within three countries, Australia, France (on sub-Antarctic île Saint-Paul) and New Zealand; all three are ACAP Parties.  Its high-seas distribution largely falls within the ambit of tuna Regional Fishery Management Organizations (tRFMOs) with which ACAP currently engages.  Further, it does not appear to be the target of a directed take for human consumption, as is the case for some other shearwater species in Australia and New Zealand.  There thus appears to be no obvious impediment to its listing, or notable consequences to the Agreement itself.  I suggest that Australia, France and New Zealand consider working together towards a nomination.  A first step could be holding a one-day expert workshop to review the species’ status associated with a meeting of the ACAP Advisory Committee.  Depending on the workshop’s findings and recommendations, the three breeding states could then produce a nomination text to be discussed at a following meeting of the Advisory Committee and its working groups.

Yelkouan Shearwater

The globally Vulnerable Yelkouan Shearwater Puffinus yelkouan is endemic to the Mediterranean region, breeding on islands within the sea and migrating eastward in to the Black Sea when not breeding.  The species is listed in Annex I (“particularly threatened”) of the EU Birds Directive and in Annex II (“requiring special protection”) of the Convention on the Conservation of European Wildlife and Natural Habitats (Bern Convention).  As for the closely related Balearic Shearwater (with which there is evidence that it may hybridise) the species is at risk to both artisanal and commercial fishery mortality, light pollution and introduced predators at breeding sites.

A banded Yelkouan Shearwater breeding in Malta, photograph by André Raine

The species is known to breed in at least nine countries around the Mediterranean Sea, with significant populations in France, Greece, Italy and Malta, as well smaller ones in Albania, Algeria, Bulgaria, Croatia and Tunisia, and possibly also in Turkey.  Of these countries, only France is an ACAP Party.  Based on what is known of its at-sea distribution, all the many political entities surrounding the Mediterranean and Black Seas will be range states.  Populations appear to be decreasing, with low breeding success at many breeding sites - and some sites have gone extinct.

In 2013 two environmental NGOs, BirdLife International and Medmaravis, jointly submitted an Information Paper to the Seventh Meeting (AC7) of the Agreement’s Advisory Committee, held in La Rochelle, France.  The paper (AC7 Inf 04) had among its recommendations that “Mediterranean countries that are Parties to ACAP are encouraged to propose Calonectris diomedea [= Scopoli’s Shearwater, categorized as Least Concern] and Puffinus yelkouan for listing in Annex 1” (click here).  Since then, no further proposals for listing the Yelkouan Shearwater have been made to the Agreement.

The consequences of listing the Yelkouan Shearwater are likely to be more significant for ACAP than for the Flesh-footed Shearwater.  Firstly, it would add up to nine more countries as breeding range states to those non-Party breeding range states (Japan, Mexico and the United States) with which ACAP already interacts, with the obvious issue of potentially over-extending the capacity of a small Secretariat.  Inviting even Greece, Italy and Malta, the most important non-Party breeding states, to ACAP meetings would also have financial and personpower consequences.  Further, ACAP may then feel the desirability of interacting  with the General Fisheries Commission for the Mediterranean (GFCM), a regional fisheries management organization (RFMO) which up to now it has had no direct dealings.

An initiative to list the Yelkouan Shearwater on ACAP's Annex 1 might come from its sole breeding Party, France, perhaps working with Italy that holds by far the largest populations.  Alternatively, the European Union could take the lead, although its Environmental Agency categorizes the bird as Least Concern, i.e. not threatened (click here).   A recent development is Malta's intention to produce a National Action Plan 2022-2030 for the species.  An international action plan could sensibly then follow, negotiated by all the breeding range states for the Yelkouan Shearwater.  Such could possibly transpire under the auspices of the European Union's LIFE Programme (a funding instrument for the environment and climate action). It is noteworthy that the Life Programme has funded a consortium of environmental NGOs in France, Greece, Malta, Portugal and Spain (the LIFE PanPuffinus! Project) to improve the conservation status of the Yelkouan Shearwater and the Balearic Shearwater by tackling threats at land and sea through transboundary collaboration.  ACAP should keep a watching brief of all these developments.

Selected Publications:

Baker, G.B. & Wise, B.S. 2005.  The impact of pelagic longline fishing on the Flesh-footed Shearwater Puffinus carneipes in eastern Australia.  Biological Conservation  126: 305-316.

Bonnaud, E., Berger, G., Bourgeois, K., Legrand, J. &  Vidal, E. 2012  Predation by cats could lead to the extinction of the Mediterranean endemic Yelkouan Shearwater Puffinus yelkouan at a major breeding site.  Ibis 154: 566-577.

Bourgeois, K. & Vidal, E. 2008.  The endemic Mediterranean yelkouan shearwater Puffius yelkouan: distribution, threats and a plea for more data.  Oryx 42: 187-194.

Cooper, J., Baccetti, N., Belda, E.J., Borg, J.J., Oro, D., Papaconstantinou, C & Sánchez, A. 2003.  Seabird mortality from longline fishing in the Mediterranean and Macaronesian waters: a review and a way forward.  Scientia Marina 67, Supplement 2: 57-64.

Cooper, J. & Baker, G.B. 2008.  Identifying candidate species for inclusion within the Agreement on the Conservation of Albatrosses and Petrels.  Marine Ornithology  36 1-8.

Jamieson, S.E. & Waugh, S.M. 2015.  An assessment of recent population trends of flesh-footed shearwaters (Puffinus carneipes) breeding in New Zealand.  Notornis 62: 8-13.

Lavers, J.L. 2014.  Population status and threats to Flesh-footed Shearwaters (Puffinus carneipes) in South and Western Australia.  ICES Journal of Marine Science: 72: 316-327.

Oppel, S., Raine, A.F., Borg, J.J., Raine, H., Bonnaud, E., Bourgeois, K. & Breton, A.R. 2011.  Is the Yelkouan shearwater Puffinus yelkouan threatened by low adult survival probabilities?  Biological Conservation 144: 2255-2263.

Priddel, D., Carlile, N., Fullagar, P., Hutton, I. & O’Neill, L. 2006.  Decline in the distribution and abundance of flesh-footed shearwaters (Puffinus carneipes) on Lord Howe Island, Australia.  Biological Conservation 128: 412-424.

Raine, H., Borg, J.J., Raine, A., Bariner, S. & Cardona, M.B. 2007.  Light Pollution and its effect on Yelkouan Shearwaters in Malta; Causes and Solutions. Malta: Life Project Yelkouan Shearwater, BirdLife Malta.

Rivers-Auty, J., Bond, A.L., Grant, M.L. & Lavers, J.L. 2022.  The one-two punch of plastic exposure: macro- and micro-plastics induce multi-organ damage in seabirds.  Journal of Hazardous Materials.  doi.org/10.1016/j.jhazmat.2022.130117.

John Cooper, Emeritus ACAP Information Officer, 01 November 2022

An adult Tristan Albatross with back wounds from mice; photographs (L - R) Kate Lawrence and Jaimie Cleeland

Lessons and insights from the failed mouse eradication attempt on Gough Island were presented in a recent webinar hosted by New Zealand’s Crown Research Institute, Manaaki Whenua - Landcare Research, a partner in the Gough Island Restoration Programme. The eradication attempt on the island’s introduced House Mice Mus musculus was carried out in 2021 during the southern hemisphere’s winter. Monitoring equipment captured footage of a single mouse in mid-November confirming the programme had been unsuccessful and dashing the hopes of those involved in the ambitious project. 

Providing insight into the project and answering questions submitted to the webinar was Conservation Biologist and Technical Advisor to the Programme, Dr Araceli Samaniego. Dr Samaniego, who has been involved in and led a number of successful mouse eradications, outlined the eradication plan, its execution, and touched on possible reasons for its failure, including the hypothesis of invasive slugs thwarting the programme’s success. Despite the mouse population increasing quickly since the eradication attempt, Dr Samaniego believes another bid at eliminating the island’s mice would be a worthwhile venture and, due to the lessons learnt this time around, has every reason to be a success. 

The 30-minute webinar, Mice squeak through eradication attempt on Gough Island - what can we learn?, is available to watch above or at the Manaaki Whenua - Landcare Research website. A transcript of the presentation and answers to questions submitted to Dr Samaniego are also available to download at the website.

For further insight on the interference of the invasive slugs during the eradication attempt, please read Dr Samaniego and colleagues' paper, “A lesson for planning rodent eradications: interference of invasive slugs during the Gough Island mouse eradication attempt in 2021”, published in the journal, Wildlife Research. 

31 October 2022

Displaying Amsterdam Albatrosses; photograph by Romain Buenadicha
In a study by Henri Weimerskirch and colleagues, Amsterdam Albatrosses were fitted with loggers capable of detecting radar emissions from fishing vessels which may help halt illegal fishing

Claudia Geib has published an article, To Stop Illegal Fishing, Send a Seabird in Nautilus, exploring the feasibility of seabirds tracking and helping stop illegal fishing. Her article draws on a current study using Peruvian Boobies to monitor anchovy fisheries but also references previous studies involving albatrosses. ACAP has highlighted research such as that by Henri Weimerskirch and colleagues which utilised geolocating loggers attached to Wandering Diomedea exulans and Amsterdam D. amsterdamensis Albatrosses to track fishing vessels by detecting the vessel’s radar. The resulting paper, “Ocean sentinel albatrosses locate illegal vessels and provide the first estimate of the extent of nondeclared fishing” was published in PNAS -Proceedings of the National Academy of Sciences of the United States of America and is available to read here.

28 October 2022