The latest ACAP Species Infographic, released today and the fourteenth to be produced in the series, is for the Near Threatened Grey Petrel Procellaria cinerea.  It is the first to be produced for an ACAP-listed petrel, the previous 13 infographics all being for albatrosses.  It is being produced in the three official ACAP languages of English, French and Spanish; versions the latter two languages will be released shortly.  The Grey Petrel infographic has been sponsored by the Australian Antarctic Program.

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 14 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.

One more ACAP Species Infographic is currently in production, for the Vulnerable White-chinned Petrel P. aequinoctialis, which will also be produced in Portuguese.  A further five species have been sponsored, with work on them to commence in the new year.

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, Jonathon Barrington, Karine Delord, Johannes Fischer, Graham Parker, Richard Phillips and Peter Ryan for their help.

*Being produced for the six ACAP-listed species that regularly visit waters off Brazil.  To date, these are 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, 14 December 2023

Hybrid Black-browed-Grey-Headed Albatross Red Y48 incubating an egg, Grey-headed Albatross Ridge, Marion Island, 21 October 2023, photograph by Michelle Risi

UPDATE:  On 07 December the next was empty, with the hybrid seen close by before it flew off. If seen again an attempt will be made to pluck a feather to assign gender.

A Black-browed Albatross Thalassarche melanophris - Grey-headed Albatross T. chrysostoma hybrid has been recorded incubating an egg on sub-Antarctic Marion Island in the southern Indian Ocean.  One of two such hybrids known from the island (click here) the colour-banded bird (left leg red Y48, right leg metal SAFRING 9A-45744) was first observed occupying an empty nest during the current 2023/24 breeding season on 06 October 2023 on Grey-headed Albatross Ridge in the south of the island.  On a second visit on 21 October the bird was seen to be incubating.  This is the first record of a hybrid albatross breeding on Marion Island, and apparently the first definite breeding by a known hybrid Thalassarche albatross anywhere (click here).  The bird’s partner is a Grey-headed Albatross (left leg red Y96, right leg metal SAFRING 9A-87577) seen on the nest prior to laying and subsequently photographed taking an incubation shift on 18 November.  The hybrid and its partner’s genders are not known.

The hybrid bird on its empty nest on 06 October 2023.  The red colour band on its left leg is partially visible, photograph by Michelle Risi

The hybrid is believed to have been metal banded on Grey-headed Albatross Ridge as a non-breeding bird in the 2008/09 breeding season.  On 7 October 2019 the colour band was added by Stefan Schoombie.  A publication in the journal Antarctic Science suggests that the bird may have fledged from the same Black-browed – Grey-headed Albatross mixed pair that successfully fledged a different hybrid bird in May 2007, that was subsequently seen (and described) back in the colony as a non-breeder nine years later in 2016.  In February 2018 this known-age bird  was photographed by Chris Jones occupying an empty nest.  That the two hybrid records are not of the same individual is confirmed because the 2007 bird was metal banded on its left leg prior to fledging (as are all fledglings within monitoring colonies on Marion Island), whereas the breeding hybrid discussed here wears its metal band on its right leg (as a bird of unknown age).

Further visits will be made during the breeding season to the hybrid’s nest to ascertain if the egg hatches and was therefore fertile.

Grey-headed Albatross red Y96 incubating on 18 November 2023 (when it was banded) is the hybrid’s partner.  Their nest is marked with a short section of a numbered PVC electrical conduit pole, photograph by Michelle Risi

Mixed species breeding pairs in the genus Thalassarche have been recorded producing fledglings between Black-browed and Campbell T. impavida Albatrosses on Campbell Island and between a Black-browed and a White-capped T. steadi Albatross on Bird Island in the South Atlantic.  Hybrids from these two mixed pairs have not been recording breeding.  Within the Diomedeidae, mixed pairs have produced hybrid young between Black-footed Phoebastria nigripes and Laysan P. immutabilis Albatrosses and between Northern Royal Diomedea sanfordi and Southern Royal D. epomophora Albatrosses.  In contrast to these Thalassarche hybrids, both Phoebastria and Diomedea hybrids have been recording breeding.

Another view of red Y48 incubating in a colony of Grey-headed Albatrosses, photograph by Michelle Risi

With thanks to Maëlle Connan, Chris Jones, Richard Phillips, Stefan Schoombie and Kim Stevens.

Selected References:

Jones, M.G.W., Techow, N.M.S., Risi, M.M., Jones, C.W., Hagens, Q.A., Taylor, F. & Ryan, P.G. 2019.  Hybridization and cuckoldry between black-browed and grey-headed albatrosses.  Antarctic Science 32-10-14.  (click here).

Moore, P.J., Taylor, G.A. & Amey, J.M. 1997.  Interbreeding of Black-browed Albatross Diomedea m. melanophris and New Zealand Black-browed Albatross D. m. impavida on Campbell Island.  Emu 97: 322-324.

Phillips, R.A., Cooper, J. & Burg, T.M. 2018.  Breeding‐site vagrancy and hybridization in albatross.  Ibis 160: 907-913. (click here).

Rutt, C. 2013.  Hybridization of the black-footed and Laysan Albatrosses.  Western Birds 44: 322-333. (click here).

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels & Michelle Risi, Marine Apex Predator Research Unit, Nelson Mandela University, South Africa, 30 November 2023

 Balearic Shearwater, mixed media by Catarina Vitorino, Artists and Biologists Unite for Nature, after a photograph by Pep Arcos

The Critically Endangered Balearic Shearwater Puffinus mauretanicus of the Mediterranean Sea is the second-last species (and the first shearwater) to be added to ACAP’s Annex 1, following a decision taken at the Fourth  Session of the Meeting of the Parties (MoP4) held in Lima, Peru in April 2012.

Endemic to Spain’s Balearic Islands, the species has an interesting taxonomic history.  It was described in 1921 by the English ornithologist Percy Lowe, who treated it as a subspecies Puffinus puffinus mauretanicus of the Manx Shearwater.  A later categorization placed it as a subspecies of the then-named Mediterranean Shearwater P. yelkouan (itself once considered a subspecies of the Manx Shearwater).  It was then considered to be a full species, with the now-named Yelkouan Shearwater as a separate species.  However, the presence of seemingly hybrid birds raised questions on the taxonomic categorisation of the Balearic and Yelkouan Shearwaters as full species.

As a full species the Balearic Shearwater was awarded the conservation status of Lower Risk/Near Threatened in 2000, and then as Critically Endangered in 2004, a category of threat it has kept through a number of reviews to the current day (click here). Its categorizaton also added to the impetus that led Spain to successfully propose the species be added to the Agreement’s Annex 1 (click here).

A molecular study published in 2021 found very little genetic difference between the Balearic and Yelkouan Shearwaters, leading to the authors of the study to suggest that the two taxa might be better considered as conspecific (click here), proposing that the Balearic Shearwater should be considered  as a subspecies of the Yelkouan as P. y. mauretanicus.  Not surprisingly, this opinion led the ACAP Taxonomy Working Group (TWG) to consider the matter and its implication for the Albatross and Petrel Agreement.  The TWG, follow its online discussions, included the matter it its report to the 13th Meeting of the ACAP Advisory Committee (AC13), held in Edinburgh, Scotland in May 2023.  The TWG wrote: “Obiol et al. (2023) conducted a comprehensive genetic analysis of the Puffinus shearwaters of the North Atlantic and Mediterranean.  They found that current taxonomies are not supported by genomic data and propose a more accurate taxonomy by integrating genomic information with other sources of evidence.  With particular relevance to ACAP, they found no support for the split of Balearic Shearwater (Puffinus mauretanicus) and Yelkouan Shearwater (P. yelkouan) into two different species and propose that these two Mediterranean taxa should be considered as conspecific.  Taxonomic precedence would then make the Balearic Shearwater a sub-species (or sub-population) of Yelkouan Shearwater.  If this analysis is accepted, this presents a difficulty for ACAP as Article 1.1 states “This Agreement shall apply to the species of albatrosses and petrels listed in Annex 1 to this Agreement”, in other words Annex 1 should list species, not separate sub-species or populations.  Guidance on this issue is requested from the Advisory Committee.”

AC13 then discussed the status of the Balearic Shearwater, noting in its report that advice from Australia that species, subspecies or populations could be listed in Annex 1 of the Agreement.  “Article I (1) of the Agreement was to be read together with Article I (2)(a) that further defines the terms ‘albatross’ and ‘petrel’.  Read together, the terms ‘albatross’ and ‘petrel’ in Article I (1) of the Agreement could refer to a species, subspecies or population of the albatross or petrel.”   This was relevant to possible future approaches to the listing in Annex 1 to the Agreement of the Balearic Shearwater.  The Advisory Committee then agreed in its meeting report to await the outcome of deliberations by the taxonomic committee of the International Ornithological Congress (IOC), before considering further any consequences for Annex 1 of the Agreement.

The authors of the 2022 taxonomic review state that the two taxa “are good examples of differentiated populations worthy of consideration as intraspecific units that represent unique morphological, ecological and genetic diversity for conservation of biodiversity.  We stress that developing action plans for P. mauretanicus and P. yelkouan should not depend on whether these taxa are classified as separate species or not.”  With this in mind, it seems sensible that the Balearic Shearwater remains listed by the Agreement on Annex 1, changing its scientific designation to P. yelkouan mauretanicus, if that becomes the view of the IOC.

Yelkouan Shearwaters in flight, photograph by Pep Arcos

It is also thought worthwhile to consider the situation of the Yelkouan Shearwater in relation to ACAP.  Its current category of threat is Vulnerable.  If it is reclassified as including the Critically Endangered Balearic Shearwater (sensu stricto), this might conceivably result in it being considered Endangered, and thus potentially of greater interest to ACAP.  In an ACAP Monthly Missive written a year ago I considered whether the Yelkouan Shearwater should be listed on ACAP’s Annex 1, writing that such a listing “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 person power consequences.” I concluded that ACAP should keep a “watching brief” on international efforts to improve the Yelkouan Shearwater’s conservation status.  It has been quite some time since ACAP added a new species to its Annex 1 (the Vulnerable Pink-footed Shearwater Ardenna creatopus in 2015 being the last (click here).  I shall follow with interest how ACAP treats any changes to its listing of threatened shearwaters in future years.

Reference

Obiol, J.F., Herranz, J.M., Paris, J.R., Whiting, J.R., Rozas, J., Riutort, M. & González-Solís, J. 2022.  Species delimitation using genomic data to resolve taxonomic uncertainties in a speciation continuum of pelagic seabirds.  Molecular Phylogenetics and Evolution 179.  doi.org/10.1016/j.ympev.2022.107671.

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 12 December 2023

NOTE: There will be a break in posting ACAP Monthly Missives in the New Year.  I hope to restart the series if suitable subjects come to mind, or guest missives are offered.

From the paper: Fig 2. The relationship between wing loading (N m−2) and aspect ratio (dimensionless) for flying birds

Lesley Thorne (School of Marine and Atmospheric Sciences, Stony Brook University, USA) and colleagues have published a review and synthesis on the impact of wind on seabirds in the journal Marine Ecology Progress Series.

The paper’s abstract follows: “For decades, studies have highlighted links between wind patterns and the behavior, ecology, distribution, energetics and life history of seabirds. However, only relatively recently have advancements in tracking technologies and improvements in the resolution of globally-available wind data allowed wind impacts on seabirds to be quantified across multiple spatiotemporal scales. Here, we review and synthesize current knowledge of the effects of wind on seabirds. We first describe global patterns of wind circulation and relevant atmospheric processes and discuss the relationship between seabird morphology, flight performance and behavior relative to wind. We then develop a conceptual model linking seabird movement strategies to wind, morphology, flight capabilities and central-place constraint. Finally, we examine how wind influences seabird populations via effects on flight efficiency and energetics, and wind impacts associated with climate variability and severe weather. We conclude by highlighting research priorities for advancing our understanding of the effects of wind on seabird ecology and behavior; these include assessing how and to what extent seabirds use ocean waves for efficient flight, understanding how seabirds sense and anticipate wind patterns, and examining how wind has shaped seabird evolution. Future research should also focus on assessing how wind modulates habitat accessibility, and how this knowledge could be incorporated into theory of seabird habitat use. Moreover, approaches that focus on mechanistic links between climate, wind and demography are needed to assess population-level effects, and will be imperative to understanding how seabirds may be impacted by climate-driven changes to wind patterns.“

Reference: 

Thorne LH, Clay TA, Phillips RA, Silvers LG, Wakefield ED (2023) Effects of wind on the movement, behavior, energetics, and life history of seabirds. Mar Ecol Prog Ser 723:73-117. https://doi.org/10.3354/meps14417

11 December 2023