Cory's Shearwater in flight

Raül Ramos (Institute for Research on Biodiversity (IRBIO) Universitat de Barcelona, Barcelona, Spain) and colleagues have published in the journal Ecological Indicators on the presumed stability in trophic level over time in Cory’s Shearwaters Calonectris borealis based on feather analysis.

The paper’s abstract follows:

“Despite its importance for ecology and conservation, we are still far from understanding how environmental variability interacts with intrinsic factors and individual specialization to determine trophic strategies of long-lived taxa, mostly due to difficulties in studying the same animals over extended periods. Here, by yearly consistently sampling the first primary feather of 99 Cory’s shearwaters (Calonectris borealis) foraging in the Canary Current (CC) upwelling ecosystem, we provide robust evidence on the individual changes of isotopic ratios of carbon (δ¹³C) and nitrogen (δ¹⁵N) over 17 years. We reported a slight longitudinal decline of δ¹³C values throughout 2001–2017, even after being adjusted for the marine Suess effect (linked to the increasing CO₂ emissions). Although CC is often considered to be overexploited by industrial fisheries, we could not detect a decline in Cory’s shearwater trophic level indicating a change in the trophic web structuring, as revealed by δ¹⁵N. We found negative correlations of δ¹³C and δ¹⁵N with the CC upwelling intensity, indicating annual variability in baseline isotopic levels propagates through the food chain and it integrates in predators’ tissues. Low individual repeatabilities among years at population level indicates low long-term specialization, suggesting long-lived individuals foraging on highly productive areas can adjust their foraging strategies and diet according to environmental variability. However, individual-level repeatabilities in isotopic values showed a range of individual specialization within the population, indicating most individuals are generalist and a few of them highly specialized. First, although we found a clear influence of the upwelling intensity on the trophic ecology of birds, we could not detect any temporal trend in the trophic level of the Cory’s shearwater population, suggesting a stability in the structure of the pelagic food web of the CC over the last two decades despite the fishing pressure. Second, the existence of individual specialization highlights the importance of considering the repeated sampling of individuals to detect small changes in the trophic ecology of a population. Finally, the coexistence of individuals with different degree of specialization (from extremely flexible [generalists] to highly consistent individuals [specialists]) within a population can have deep implications on the capacity of populations to cope with environmental change.”

Reference:

Ramos, R., Reyes-González, J.M., Morera-Pujol, V., Zajková, Z. & Militão, T. 2020.  Disentangling environmental from individual factors in isotopic ecology: a 17-year longitudinal study in a long-lived seabird exploiting the Canary Current.  Ecological Indicators 111.  doi.org/10.1016/j.ecolind.2019.105963.

John Cooper, ACAP Information Officer, 21 July 2020

This book is a thorough introduction to the complex task of rehabilitating procellariiform seabirds written by world experts in the field of seabird medicine and rehabilitation.  It was written for use in Brazil and is only available in Portuguese; however, the content is universally applicable.  Rehabilitation of albatrosses, petrels and other procellariiform seabirds is a difficult task that requires exceptional skill and specialised techniques and equipment.  This publication documents the most successful techniques learned by rehabilitation centres around the world.  Veterinary care and stabilisation, correct hosing and enclosures for these birds, handling and transport, feeding, swimming and safe release are just some of the important topics covered.  This publication will go a long way towards making procellariiform rehabilitation more professional and improving the number of birds that are successfully released after rehabilitation.  I hope that the authors secure funding for English and Spanish translations in the near future.

The book’s chapter headings follow in Portuguese with English translations in parentheses:

1. INTRODUÇÃO (Introduction)

2. BIOLOGIA GERAL E ESPÉCIES COM OCORRÊNCIA NO BRASIL (General biology and species occurring in Brazil)

3. AMEAÇAS À CONSERVAÇÃO DOS PROCELLARIIFORMES NO BRASIL (Threats to the conservation of procellariiforms in Brazil)

4. INSTALAÇÕES E RECINTOS (Facilities and enclosures)

5. BIOSSEGURANÇA E USO DE EQUIPAMENTOS DE PROTEÇÃO INDIVIDUAL (Biosafety and use of personal protective equipment)

6. CONTENÇÃO FÍSICA, ESTABILIZAÇÃO EM CAMPO E TRANSPORTE (Physical containment, field stabilization and transportation)

7. ADMISSÃO E EXAME FÍSICO (Admission and physical examination)

8. ASPECTOS GERAIS DE MEDICINA E REABILITAÇÃO (General aspects of medicine and rehabilitation)

9. REABILITAÇÃO DE PROCELLARIIFORMES OLEADOS (Rehabilitation of oiled procellariiforms)

10. DEVOLUÇÃO À NATUREZA (SOLTURA) (Return to nature (release))

11. EUTANÁSIA (Euthanasia)

12. BIOMETRIA, COLHEITA DE AMOSTRAS BIOLÓGICAS E NECROPSIA (Biometrics, collection of biological samples and necropsy

13. DOCUMENTAÇÃO E FOTODOCUMENTAÇÃO (Documentation and photo-documentation)

14. PRINCIPAIS ENFERMIDADES (Major diseases)

15. CONSIDERAÇÕES DE BIOSSEGURANÇA PARA ATIVIDADES DE CAMPO (Biosafety considerations for field activities)

With thanks to Patricia Pereira Serafini.

Reference:

Hurtado, R., Saviolli, J.Y. & Vanstreels, R.E.T. (Eds) 2020.  Reabilitação de Procellariiformes: (albatrozes, petréis, pardelas).  Santos, Brazil: Editora Comunnicar.  111 pp.  Many illustrations in colour.  Published electronically.  ISBN 978-85-8136-138-3.

David Roberts, Clinical Veterinarian, Southern African Foundation for the Conservation of Coastal Birds (SANCCOB), 20 July 2020

Manx Shearwater at sea, photograph by Nathan Fletcher

Annette Fayet (Department of Zoology, University of Oxford, UK) and colleagues have published online in the open-access journal Marine Ornithology on the migration route of western Atlantic Manx Shearwaters Puffinus puffinus.

The paper’s abstract follows:

“Manx Shearwaters are transequatorial migrants, and most of the world's population breeds in Britain and winters off the Patagonian Shelf in the western South Atlantic.  The migration route of British birds follows a well-known clockwise movement between the North and South Atlantic, taking advantage of the winds.  Whether this main Manx Shearwater migration corridor is used by the smaller populations breeding in the western North Atlantic is unknown.  Here, we report our findings from tracking two adults from a newly-established colony of Manx Shearwaters in Maine, USA using miniature geolocators.  The tracked shearwaters followed a post-breeding migration route southward along the US East Coast, through the Caribbean Sea, and along the coast of eastern South America.  Such a route greatly differs from the western North Atlantic birds' southbound migration route, being instead the reverse of the British birds' spring migration route.  We also used the tracking data to provide insight into the phenology of the birds' annual cycle.  Although our sample size is very small, our findings reveal a previously unknown migration route of Manx Shearwaters and raise questions about the origin of birds on western North Atlantic colonies and the mechanisms controlling migratory direction in the species.”

Reference:

Fayet, A.L., Shannon, P., Lyons, D.E. & Kress, S.W. 2020.  Manx shearwaters Puffinus puffinus breeding in the western Atlantic follow a different migration route from their eastern Atlantic conspecifics.  Marine Ornithology 48: 179-183.

John Cooper, ACAP Information Officer, 17 July 2020

Black-footed Albatross chicks of the 2018 translocation cohort in the James Campbell National Wildlife Reserve, photograph from Pacific Rim Conservation

Twenty-five Near Threatened Black-footed Albatross Phoebastria nigripes chicks were transported by air from the Midway Atoll National Wildlife Refuge to the James Campbell National Wildlife Refuge on the Hawaiian island of Oahu in February this year.  Since then the birds have been hand fed behind a predator-proof fence until fledging by the environmental NGO Pacific Rim Conservation.  This is the fourth year of the project that aims to establish a new breeding colony protected against predicted sea-level rise which will deleteriously affect most of the albatrosses’ low-lying breeding sites in the North Pacific.  It is hoped that after three to five years at sea the young albatrosses will return to the James Campbell NWR to breed (click here).

All the 25 translocated Black-footed Albatrosses have now successfully fledged; one being watched by a drone as it flew out to sea.  Fittingly, the first one fledged on 19 June: World Albatross Day!  The last bird left on 12 July.  This brings the total fledged over four years to 86, out of 90 chicks collected from their original breeding sites (information from Lindsay Young, Pacific Rim Conservation and earlier posts to ACAP Latest News).

Watch the six-minute video here on hand-rearing the 2017 cohort of Black-footed Albatrosses in the James Campbell NWR.

Pacific Rim Conservation has translocated chicks of three other seabird species from low-lying atolls to the refuge to be hand reared: Laysan Albatross P. immutabilis, Bonin Petrel Pterodroma hypoleuca and Tristram’s Storm Petrel Hydrobates tristrami.

The effort to create a new Black-footed Albatross colony considered safe from sea-level rise is being undertaken by Pacific Rim Conservation in partnership with the US Fish & Wildlife Service.  Read more on their translocation efforts here.

With thanks to Lindsay Young, Pacific Rim Conservation.

Reference:

VanderWerf, E.A., Young, L.C., Kohley, C.R., Dalton, M.E., Fisher, R., Fowlke, L., Donohue, S. & Dittmar, E. 2019.  Establishing Laysan and black-footed albatross breeding colonies using translocation and social attraction.  Global Ecology and Conservation doi.org/10.1016/j.gecco.2019.e00667.

John Cooper, ACAP Information Officer, 16 July 2020