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Fieldworkers restrain an incubating Wandering Albatross at Marion Island for taking moult photographs under permit; the box on the nest protects the egg from Subantarctic Skuas; the publication notes that there was no evidence that photographing incubating Wandering Albatrosses and Northern Giant Petrels influenced their breeding performance

Alexis Osborne and Peter Ryan (FitzPatrick Institute of African Ornithology, University of Cape Town, South Africa) have published in the journal Ostrich Journal of African Ornithology on using digital photography to study wing moult of breeding Wandering Albatrosses Diomedea exulans and giant petrels Macronectes spp.

The paper’s abstract follows in English and French.

“Scoring moult from live birds in the hand takes time, thereby increasing the handling stress to the birds. We show that digital photography can be used to efficiently study moult extent across multiple feather tracts. We photographed the upper wings of incubating albatrosses and giant petrels to infer which remiges and greater secondary coverts had been replaced in the previous year. Wear contrasts differentiating ‘new’ from ‘old’ feathers were easier to see for dark than white feathers, and could be enhanced by increasing image saturation. Repeat photography of the same individuals in successive years showed that the inner secondaries and associated greater coverts wear faster than the central secondaries, and this needs to be considered when aging feathers of unknown birds. Scoring primary moult in the hand took more than twice as long as photographing the entire wing. There were a few discrepancies between moult scores from photographs and birds scored in the hand, mostly due to older feathers being scored as new. These errors likely resulted from rushing to score moult in the hand under indifferent lighting conditions. However, it is essential to ensure that the wing is fully spread, so that all feathers are visible. Photographing had no impact on hatching success and it is a useful and reliable method to study the extent and symmetry of moult.

The upperwing of a Northern Giant Petrel at Marion Island showing an unmodified (top) and modified (bottom) image, where the saturation was increased to exaggerate wear contrast differences; photographs from Alexis Osborne's MSc thesis

Utilisation de la photographie numérique pour étudier l’étendue de la mue chez les oiseaux de mer nicheurs

L’évaluation de la mue des oiseaux vivants dans la main prend du temps, ce qui augmente le stress de manipulation pour les oiseaux. Nous montrons que la photographie numérique peut être utilisée pour étudier efficacement l’étendue de la mue sur de multiples éstensions de plumes. Nous avons photographié les ailes supérieures d’albatros et de pétrels géants en incubation pour déduire quelles rémiges et grandes couvertures secondaires avaient été remplacées l’année précédente. Les contrastes d’usure qui différencient les ‘nouvelles’ des ‘anciennes’ plumes étaient plus faciles à voir pour les plumes sombres que pour les blanches, et pouvaient être améliorés en augmentant la saturation de l’image. Des photographies répétées des mêmes individus au cours d’années successives ont montré que les secondaires internes et les grandes couvertures associées s’usent plus rapidement que les secondaires centrales, ce qui doit être pris en compte lors du vieillissement des plumes d’oiseaux inconnus. L’évaluation manuelle de la mue primaire demande deux fois plus de temps que la photographie de l’aile entière. Des écarts ont été entre notées entre les marques de mue des photographies et les oiseaux marqués à la main, principalement en raison des plumes plus anciennes qui étaient marquées comme neuves. Ces erreurs résultaient probablement de la précipitation pour marquer la mue à la main dans des conditions d’éclairage indifférentes. Cependant, il est essentiel de veiller à ce que l’aile soit entièrement déployée, afin que toutes les plumes soient visibles. La photographie n’a pas eu d’impact sur le succès de l’éclosion et constitue une méthode utile et fiable pour étudier l’étendue et la symétrie de la mue.”

Read the abstract of Alexis Osborne’s 2020 MSc thesis entitled Understanding Moult Patterns in Albatrosses and Petrels breeding on Marion and Gough Islands” (Download the full thesis from here).

With thanks to Janine Dunlop, Niven Librarian, FitzPatrick Institute, University of Cape Town and Alexis Osborne, Gough Island Restoration Programme

Reference:

Osborne, A. & Ryan, P.G. 2021.  Using digital photography to study moult extent in breeding seabirds.  Ostrich doi10.2989/00306525.2021.1897699 plus two photographs in supplementary information.

John Cooper, ACAP Information Officer, 22 May 2021

A Critically Endangered Tristan Albatross family on Gough Island; artwork by Di Roberts from photographs by Tom McSherry & Michelle Risi

Today is Endangered Species Day, a campaign of the Endangered Species Coalition, a USA-based environmental NGO.  The coalition’s mission “is to stop the human-caused extinction of our nation’s at-risk species, to protect and restore their habitats, and to guide these fragile populations along the road to recovery”.

“Every year on the third Friday in May, thousands of people around the world participate in Endangered Species Day by celebrating, learning about, and taking action to protect threatened and endangered species.  Wildlife refuges, zoos, aquariums, gardens, schools, libraries, museums, community groups, nonprofits, and individuals hold special programs or events for people of all ages.  Due to the global coronavirus crisis, the programs organized for Endangered Species Day 2021 will primarily be online events, digital actions, and remote activities.”  2021 will be the 16th time the day has been marked.

Eleven of the 31 ACAP-listed albatrosses, petrels and shearwaters have been categorized as either globally Critically Endangered or Endangered by the International Union for the Conservation of Nature (IUCN), nine of them being albatrosses.  The three Critically Endangered species are the Tristan Diomedea dabbenena and Waved Phoebastria irrorata Albatrosses and the Balearic Shearwater Puffinus mauretanicus.

And tomorrow is World Biodiversity Day, known more formally as the International Day for Biological Diversity.

John Cooper, ACAP Information Officer, 21 May 2021

Southern Giant Petrel by Pat Latas, from a photograph by Michelle Risi

Júlia Victória Grohmann Finger (Laboratório de Ornitologia e Animais Marinhos, Universidade do Vale do Rio dos Sinos, São Leopoldo, Brazil) and colleagues have published in the journal Polar Biology on two instances of cannibalism by male Southern Giant Petrels on the Antarctic Peninsula.

A male Southern Giant Petrel  feeds on a conspecific chick after removing it from its nest, from the publication

The short note’s abstract follows:

“Southern giant petrels (Macronectes giganteus) are a scavenger and predatory species with highly opportunistic feeding habits. Although cannibalism is a likely behavior for a predatory and colonial species, there are no confirmed records of this behavior for giant petrels. In this study, we describe two cases of cannibalism in a population of southern giant petrels breeding at Harmony Point (62°18′S; 59°10′W), Nelson Island. In both cases, a male giant petrel preyed upon a nestling. Our records confirm that heterocannibalism is part of the behavior repertoire of male southern giant petrels.”

With thanks to Janine Dunlop, Niven Librarian, FitzPatrick Institute, University of Cape Town.

Reference:

Grohmann Finger, J.V., Corá, D.H., Petry, M.V. & Krüger, L. 2021.  Cannibalism in southern giant petrels (Macronectes giganteus) at Nelson Island, Maritime Antarctic Peninsula. Polar Biology doi.org/10.1007/s00300-021-02859-8. Scroll down on the reference to watch a short video of cannabalistic feeding.

*Raffish:  “unconventional and slightly disreputable, especially in an attractive way”.

John Cooper, ACAP Information Officer, 20 May 2021

Balearic Shearweater at sea, photograph by Pep Arcos

Maite Louzao (Marine Research, Basque Research and Technology Alliance, Pasaia, Spain) and colleagues have published open access in the electronic journal PeerJ on the at-sea movements of juvenile Balearic Shearwaters Puffinus mauretanicus (Critically Endangered).

The paper’s abstract follows:

“Increasing human activities have detrimental consequences on marine ecosystems and their impact can have cumulative effects. Within marine ecosystems, seabirds respond to ecosystem variability and face multiple human pressures, especially threatened species. In long-lived species, juveniles and immatures could represent up to 50% of the total population, but their migratory movements remain largely unknown. Here, we depict the migratory patterns of juvenile Balearic shearwaters Puffinus mauretanicus, the most threatened European seabird, using miniaturised satellite transmitters. At the end of the 2012 breeding season, five tagged juveniles left the breeding colonies of Eivissa Island (western Mediterranean) the first week of July. They moved westwards to reach the Atlantic Ocean between 3 and 13 days afterwards. Juveniles showed a two-phase migratory pattern: they first travelled slower close to the breeding colonies, and then moved towards their wintering areas in the Atlantic Ocean by rapid directional movements. Environmental cues (e.g.,marine productivity, water mass distribution, frontal systems) might have a prominent role in driving the migratory patterns of juvenile Balearic shearwaters, moving from warm and poor marine areas in the Mediterranean Sea to cooler and rich non-breeding grounds in the Atlantic Ocean. Based on observational findings, we observed certain spatial overlap of juvenile Balearic shearwaters with areas of high human impact, but the relationship between flying travel speed and both fishing effort and cumulative human impacts were not statistically significant. These results suggest that more research is needed to assess whether the movement patterns of migrating juveniles are affected by human activities. Therefore, understanding the at-sea spatial ecology of juveniles should be a priority for research and conservation due to the importance of this population component in long-lived species, as well as assessing their vulnerability to multiple anthropogenic pressures.”

Reference:

Louzao, M., Delord, K., García, D., Afán, I., Arcos, J.M. & Weimerskirch, H. 2021.  First days at sea: depicting migration patterns of juvenile seabirds in highly impacted seascapes. PeerJ 9: e11054 doi.org/10.7717/peerj.11054.

John Cooper, ACAP Information Officer, 19 May 2021