Julie McInnes (Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia) and colleagues have published a review article in the ICES Journal of Marine Science that looks at methods to analyse diets of albatrosses.

The paper’s abstract follows:

“Many seabird populations are threatened by interactions with commercial fisheries, and climate change.  Understanding their prey requirements and dietary flexibility in this context is important for effective conservation and management.  However, changes in the methods used to assess diet, as well as the spatial and temporal coverage of monitoring schemes, may reduce our ability to detect and monitor these marine threats.  To help assess conservation priorities linked to diet, we performed a systematic review of 109 albatross diet papers published between 1950 and 2016, which corresponded to 296 studies when stratified by sampling year, breeding site, and breeding species. We assessed the methods used, changes over time, and spatial and temporal sampling coverage by species and island group. Most albatross studies have focused on chick-rearing, and diet during other breeding phases is comparatively poorly known. Furthermore, chicks are more commonly sampled than adults and very rarely immature birds, all of which may differ in diet composition.  There was a pronounced shift over time in the preferred method of characterising diet, from the morphological examination of prey remains to stable isotope analysis of tissue. This shift has reduced the volume of detailed taxonomic information available from morphological studies.  This difference in resolution hinders the ability to detect changes in prey species, with implications for management of threatened albatrosses and for monitoring broader changes in marine ecosystems. In a knowledge gap analysis for important breeding colonies (with >5% of global population), we identified key sites where existing monitoring has provided a foundation for robust longitudinal diet studies.  Maintaining and augmenting these long-term research programmes will enable analyses of the impacts of changing climate and fishing practices on seabird populations and facilitate the timely identification and implementation of management options.”

Sooties like squid!  Sooty Albatross family on Gough Island, photograph by Kalinka Rexer-Huber

With thanks to Richard Phillips.

Reference:

Julie C. McInnes, J.C., Raymond, B., Phillips, R.A., Jarman, S.N., Lea, M.-A. & Alderman, R. 2016.  A review of methods used to analyse albatross diets—assessing priorities across their range  ICES Journal of Marine Science doi:10.1093/icesjms/fsw105.

John Cooper, ACAP Information Officer, 24 June 2016

UPDATE:  click here for the PDF.

Jennifer Lavers (Institute for Marine and Antarctic Studies, University of Tasmania, Battery Point, Australia) and Alex Bond have published in the Marine Pollution Bulletin on correlations between ingested plastics and trace elements in two seabird species on Midway Atoll.

The paper’s abstract follows:

"Seabirds are declining faster than any other group of birds, with plastic ingestion and associated contaminants linked to negative impacts on marine wildlife, including >170 seabird species.  To provide quantitative data on the effects of plastic pollution, we sampled feathers and stomach contents from Laysan Albatross (Phoebastria immutabilis) and Bonin Petrel (Pterodroma hypoleuca) on Midway Atoll, North Pacific Ocean, and assessed our ability to detect change over time by synthesizing previous studies.  Between 25 and 100% of fledglings exceed international targets for plastic ingestion by seabirds.  High levels of ingested plastic were correlated with increased concentrations of chlorine, iron, lead, manganese, and rubidium in feathers.  The frequency of plastic ingestion by Laysan Albatross and concentration of some elements in both species is increasing, suggesting deterioration in the health of the marine environment.  Variability in the frequency of plastic ingestion by Laysan Albatross may limit their utility as an indicator species.”

Laysan Albatross guards its newly-hatched chick on Midway Atoll, photograph by Pete Leary

Reference:

Lavers, J.L. & Bond A.L. 2016.  Ingested plastic as a route for trace metals in Laysan Albatross (Phoebastria immutabilis) and Bonin Petrel (Pterodroma hypoleuca) from Midway Atoll.  Marine Pollution Bulletin doi:10.1016/j.marpolbul.2016.06.001.

John Cooper, ACAP Information Officer, 23 June 2016, updated 27 june 2016

Mareile Techow (Percy FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch, South Africa) and colleagues have published in the open-access journal Polar Research on the origins of White-chinned Petrels Procellaria aequinoctialis caught on longlines in New Zealand and South African waters.

The research note’s abstract follows:

“The white-chinned petrel (Procellaria aequinoctialis) is the seabird species most frequently killed by fisheries in the Southern Ocean and is listed by the International Union for the Conservation of Nature and Natural Resources as globally vulnerable. It breeds around the sub-Antarctic, but genetic data identified two subspecies: P. a. aequinoctialis from islands in the Atlantic and Indian Oceans and P. a. steadi from the New Zealand sub-Antarctic islands. We identify the region of origin of birds killed by two long-line fisheries based on differences in the mitochondrial gene cytochrome b.  All 113 birds killed off South Africa had the haplotype of P. a. aequinoctialis, whereas all the 60 birds from New Zealand had P. a. steadi haplotypes.  The two subspecies of white-chinned petrels thus appear to disperse to different regions irrespective of their age, which accords with the tracking data of adult birds.  Our finding has significant implications for managing the bycatch of this species by regional fisheries.”

With thanks to Mark Tasker.

White-chinned Petrel, photograph by Andy Wood 

Reference:

Techow, N.M.S.M., O’Ryan, C., Robertson, C.J.R. & Ryan, P.G. 2016.  The origins of white-chinned petrels killed by long-line fisheries off South Africa and New Zealand.  Polar Research 35, 21150 http://dx.doi.org/10.3402/polar.v35.21150.

John Cooper, ACAP Information Officer, 22 June 2016

Las Malgrats are a group of two islands and a small stack off the south coast of the tourist locality of Calvià, on the west coast of the bay of Palma de Mallorca, Balearic Islands, Spain in the western Mediterranean.  The largest island is Malgrats (88 ha, maximum height 64 m).  Conills is 11 ha in size with a maximum height of 29 m.  Conills lies 191 m off the coast of Mallorca, and Malgrats is 91 m off Conills.  Foradada is a small barren rock 21 m off the coast of Mallorca.  The islands support low scrubland with plants adapted to seabird guano.

Malgrats from Mallorca (left Malgrats and right Conills). The touristic built-up area of Calvià can be seen along the coast

Malgrats from Conills

The limestone Malgrats Island contains a large number of crevices and small caves with high sea cliffs on the northern side.  The islands have never been inhabited and their rugged terrain and difficult access deter visitors.  During the last century the Malgrats were used for artillery practice.

Both islands support ideal nesting habitat for the ACAP-listed and Critically Endangered Balearic Shearwater Puffinus mauretanicus with 250 pairs on Malgrats, and 50 on Conills in 2009.  The breeding colony of Malgrats was discovered in the 1980s although local fishers used to exploit the shearwaters in the 1940s during the hard years following Spain’s Civil War.

Scopoli’s Shearwaters Calonectris diomedea breed in small numbers on Malgrats and Conills.  Mediterranean Storm Petrels Hydrobates pelagicus melitensis have been observed visiting Balearic Shearwater caves but breeding has not been recorded.

Black Rats Rattus rattus (50/ha in the late 1980s) and European Rabbits Oryctolagus cuniculatus (now extinct) were once common on the islands - in Catalan conill means rabbit.  Balearic Shearwaters then only bred in small coastal caves and in some breeding success was quite low.  In 1987 bait stations were laid out on the islands to control the rats, the first time in the Balearics.  In 2006/07 hand broadcasting poison bait successfully eradicating the rats.  Because the Malgrats Islands are very close to Mallorca reinvasions are likely to occur.

Balearic Shearwater in its breeding cave, photograph by Daniel Oro

This boulder screen on Conills was once a large cave, the large boulders were part of the cave's roof.

Balearic Shearwaters only started to breed on Conills after rats were eradicated in 2007

Three pairs of Balearic Shearwaters breed in this small cave on Conills. Balearic Shearwaters only breed in caves and crevices with soft sediment covering the floor, laying their eggs in small depressions dug out in the sediment

A Balearic Shearwater crevice on Malgrats; guano can be observed near the entrance

The islands form a Special Protection Area (SPA) and are fully protected, but as yet do not have a management plan.  Rodent presence has not been monitored since 2009.  The surrounding sea makes up the Illes Malgrats Marine Reserve declared in 2004.

Malgrats lies off the coast of one of the most important tourist destinations in Mallorca. Light pollution is increasing along the nearby coast, and is a potential threat to Balearic Shearwaters breeding on Malgrats.  Light pollution from street lights should be reduced in coastal areas near the shearwater colonies.

Malrats and Conills

The coast of Mallorca from Conills.  Fallouts of fledged Balearic Shearwaters are common along this coast

References:

Aguilar, J.S. & Cózar, E. 1989.  Campaña de desratización en los islotes de Malgrats y su posible incidencia en la avifauna nidificante.  In: López-Jurado, C. (Ed.).  Actas de la IV Reunión del Grupo Ibérico de Aves Marinas, Sant Francesc Xavier de Formentera 29 de Octubre al 1 de Noviembre de 1988. Palma de Mallorca: Grup Balear d'Ornitologia i Defensa de la Naturalesa.  pp. 55-60

Arcos, J.M. 2011.  International Species Action Plan for the Balearic Shearwater, Puffinus mauretanicus.  Madrid: SEO/BirdLife & BirdLife International.  51 pp.

Capellà, L. 1989.  Observaciones sobre la Pardela Pichoneta Puffinus mauretanicus de las Baleares.  In: López-Jurado, C. (Ed.).  Actas de la IV Reunión del Grupo Ibérico de Aves Marinas, Sant Francesc Xavier de Formentera 29 de Octubre al 1 de Noviembre de 1988.  Palma de Mallorca: Grup Balear d'Ornitologia i Defensa de la Naturalesa.  pp. 61-67.

McMinn, M. & Rodríguez, SA. 2010.  Islas, ratas y aves: historias de éxtos y fracasos.  In: Álvarez, C. (Ed.). Seminari sobre espècies introduïdes i invasores a les Illes Balears.  Sóller: Govern de les Illes Balears, Conselleria de Medi Ambient i Mobilitat.  pp. 115-126.

Oliver Ramón D. & Vera Mas, B. 2010. La mar quotidiana. Cartes d'un pescador. Palma de Mallorca: Miquel Font Editor.

Rodríguez, A., García, D., Rodríguez, B., Cardona, E., Parpal, L. & Pons, P. 2015.  Artificial lights and seabirds: is light pollution a threat for the threatened Balearic petrels?  Journal of Ornithology 156: 893-902.

Sunset over Malgrats

Landscape photographs from Miguel McMinn

Miguel McMinn, Skua Gabinet d'Estudis Ambientals SLP, Mallorca, Spain 20 June 2016