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Raül Ramos (Departament de Biologia Evolutiva, Universitat de Barcelona, Spain) has published in the open-access journal Ecology and Evolution on migration strategies of four different populations of Scopoli's Shearwaters Calonectris diomedea.

The paper’s abstract follows:

“Variability in long‐distance migration strategies is still poorly understood due to the fact that individuals are often tracked from a single colony/population. Transoceanic migrations of Scopoli's shearwaters (Calonectris diomedea) across the Strait of Gibraltar (SoG) have been tracked from several breeding colonies isolatedly, and factors related to the variability in phenological schedules among different populations remain, therefore, not well‐understood. Using light‐level geolocator data, I examined the autumn (postbreeding) and spring (prebreeding) migratory passage dates through SoG of four populations of Scopoli's shearwater spread along the longitudinal breeding range of the species. Additionally, I also estimated the at‐sea activity patterns (from immersion data) during both migratory passages, as well as the body size (from morphometric data) of the individuals of these populations. On average, Scopoli's shearwaters leave the Mediterranean (cross SoG) on 31 October ± 1.8 days on their autumn migrations and return on 03 March ± 1.6 days on their spring migrations. At the population level, there was a clear gradient in the timing of crossing SoG: birds from the westernmost populations (Murcia, SE Spain) were the first ones in leaving the Mediterranean while easternmost breeders (Paximada, Crete) were the last ones. In spring, only birds from the largest breeding population (Zembra, Tunisia) seemed to advance their return and crossed SoG significantly earlier than birds tracked at the remaining populations. In both passages, shearwaters from central and eastern populations spent more time flying than their conspecifics from the western Mediterranean. Scopoli's shearwater populations display a differential phenology and behavior in their migratory passages through SoG. The longitudinal gradient in body size already reported for the species could be an evolutionary response to an obvious trade‐off between sharing common wintering grounds in the Atlantic Ocean and the temporal constraints of restoring physiological condition in those grounds.”

Scopoli's Shearwater at sea, photograph by 'Pep' Arcos

Reference:

Ramos, R. 2019.  Crossing the Pillars of Hercules: understanding transoceanic migrations of seabirds throughout their breeding range.  Ecology and Evolution doi.org/10.1002/ece3.5079.

John Cooper, ACAP Information Officer, 28 July 2019

Raül Ramos (Departament de Biologia Evolutiva, Universitat de Barcelona, Spain) and colleagues have published in the journal Bird Study on the at-sea movements of a juvenile Cory’s Shearwater Calonectris borealis from the Canary Islands.

The paper’s abstract follows:

“Using geolocator-immersion loggers, we tracked for the first time the migration of one Cory’s Shearwater Calonectris borealis fledgling, from its breeding colony in the Canary Islands, and along its first year of life. The juvenile bird initially followed the same migratory path as the adults but visited different areas of the Central and the South Atlantic Ocean.”

Cory's Shearwater at sea, photograph by John Graham

Reference:

Raül Ramos, R., Morera-Pujol, V., Cruz-Flores, M., López-Souto, S., Brothers, M. & González-Solís, J. 2019.  A geolocator-tagged fledgling provides first evidence on juvenile movements of Cory’s Shearwater Calonectris borealis.  Bird Study doi.org/10.1080/00063657.2019.1638341.

John Cooper, ACAP Information Officer, 27 July 2019

Michelle Risi (FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch, South Africa) and colleagues have published in the journal Polar Biology on plumage and bill abnormalities in Grey-headed Thalassarche chrysostoma and Light-mantled Phoebetria palpebrata Albatross chicks.

The short note’s abstract follows:

“Accessible colonies of Grey-headed Albatross Thalassarche chrysostoma chicks on Marion Island have been inspected for chicks presenting mouse wounds from 2015, and during these inspections we found several cases of plumage and bill abnormalities. We report on two cases of leucism and three cases of ‘bent-beak syndrome’ in Grey-headed Albatross chicks, and one case of ‘bent-beak syndrome’ in a Light-mantled Albatross Phoebetria palpebrata chick. The leucistic Grey-headed Albatross chicks were found in 2018 and 2019, and both apparently fledged successfully. Three Grey-headed Albatross chicks with deviated upper mandibles were recorded in 2015, 2018 and 2019, and a single Light-mantled Albatross chick with deviated upper mandible was recorded in a study colony in 2014. None of these chicks survived to fledge. These appear to be the first records of leucism for Grey-headed Albatross, and the first records of bill deformities in any albatross species. Although bill deformities may have been overlooked in the past among Grey-headed and Light-mantled Albatrosses at Marion Island, it is worrying that we have had four records in the last few years. Albatrosses have been intensively studied at many colonies for more than 50 years, and we would have expected previous records of the ‘bent-beak syndrome’ if it occurred naturally at low levels, suggesting a novel threat to these seabirds.”

Leucistic Grey-headed Albatross chick - with a normally-plumaged chick behind, photograph by Chris Jones

‘Bent-beak syndrome’ in a Grey-headed Albatross chick, photograph by Peter Ryan

 With thanks to Michelle Risi for information.

Reference:

Risi, M.M., Jones, C.W., Schoombie, S. & Ryan, P.G. 2019.  Plumage and bill abnormalities in albatross chicks on Marion Island.  Polar Biology doi.org/10.1007/s00300-019-02528-x.

John Cooper, ACAP Information Officer, 26 July 2019

Della Bennet (School of Biological Sciences, University of Canterbury, Christchurch, New Zealand) and colleagues have published open access in the journal Ecology and Evolution on at-sea movements of the globally Endangered and Endemic and Nationally Vulnerable Hutton's Shearwater Puffinus huttoni.

The paper’s abstract follows:

“The Hutton's shearwater Puffinus huttoni is an endangered seabird endemic to Kaikōura, New Zealand, but the spatial and temporal aspects of its at‐sea foraging behavior are not well known.

To identify foraging areas and estimate trip durations, we deployed Global Positioning Systems (GPS) devices and Time‐Depth Recorders (TDR) on 26 adult Hutton's shearwaters during the chick‐rearing period in 2017 and 2018.

We found Hutton's shearwaters traveled much further from their breeding grounds at Kaikōura than previously considered, with most individuals foraging in coastal and oceanic areas 125–365 km south and near Banks Peninsula. Trip durations varied from 1 to 15 days (mean = 5 days), and total track lengths varied from 264 to 2,157 km (mean = 1092.9 km).

Although some diving occurred in near‐shore waters near the breeding colony, most foraging was concentrated in four regions south of Kaikōura. Dive durations averaged 23.2 s (range 8.1 to 71.3 s) and dive depths averaged 7.1 m (range 1.5 to 30 m). Foraging locations had higher chlorophyll a levels and shallower water depths than nonforaging locations. Birds did not feed at night, but tended to raft in areas with deeper water than foraging locations.

Mapping the spatial and temporal distribution of Hutton's shearwaters at sea will be fundamental to their conservation, as it can reveal potential areas of overlap with fisheries and other industrial users of the marine environment.”

  Hutton's Shearwater at sea

 Reference:

Bennet, D.G., Horton, T.W., Goldstien, S.J., Rowe, L. & Briskie, J.V. 2019.  Flying south: foraging locations of the Hutton's shearwater (Puffinus huttoni) revealed by Time‐Depth Recorders and GPS tracking.  Ecology and Evolution doi.org/10.1002/ece3.5171.

John Cooper, ACAP Information Officer, 25 July 2019