ACAP Latest News

Read about recent developments and findings in procellariiform science and conservation relevant to the Agreement on the Conservation of Albatrosses and Petrels in ACAP Latest News.

Contact the ACAP Communications Advisor if you wish to have your news featured.

Thayer’s shading law: how does plastic colour affect ingestion by shearwaters (and other marine predators)?

Robson Santos (Departamento de Oceanografia e Ecologia, Universidade Federal do Espírito Santo, Vitória, Brazil) and colleagues have published in the journal Environmental Pollution on ingestion of plastic by marine animals including shearwaters Ardenna and Puffinus spp.

The paper’s abstract follows:

“In recent years marine plastic pollution has gained considerable attention as a significant threat to marine animals.  Despite the abundant literature related to marine debris ingestion, only a few studies attempted to understand the factors involved in debris ingestion.  Plastic ingestion is commonly attributed to visual similarities of plastic fragments to animal's prey items, such as plastic bags and jellyfish.  However, this simple explanation is not always coherent with the variety of debris items ingested and with the species' main prey items.  We assess differences in the conspicuousness of plastic debris related to their color using Thayer's law to infer the likelihood that visual foragers detect plastic fragments.  We hypothesize that marine animals that perceive floating plastic from below should preferentially ingest dark plastic fragments, whereas animals that perceive floating plastic from above should select for paler plastic fragments.”


Short-tailed Shearwater at sea, photograph by Kirk Zufelt


Santos, R.G., Andrades, R.,Fardim, L.M. & Martins, A.S. 2016.  Marine debris ingestion and Thayer's law – The importance of plastic color.  Environmental Pollution 214: 585-588.

John Cooper, ACAP Information Officer, 26 August 2016

Population modelling of Gough Island’s Atlantic Yellow-nosed Albatrosses

Sarah Converse (US Geological SurveyPatuxent Wildlife Research Center, Maryland, USA) gave a co-authored oral presentation at this year’s North American Ornithological Conference, held in Washington, D.C., USA over 16-20 August on modelling population data collected over several decades on Atlantic Yellow-nosed Albatrosses Thalassarche chlororhynchos breeding on Gough Island.

The talk’s abstract follows:

“Integrated population models (IPM) represent a major advance in our potential to understand population dynamics.  However, species with complex life histories pose special challenges.  We developed an IPM for Atlantic Yellow-nosed Albatross (Thalassarche chlororhynchos) on Gough Island based on a 34-year dataset.  The base of the IPM is a multi-event mark-recapture model which accounts for multiple observable and partially-unobservable latent states.  The multi-event model is combined with nesting colony counts to form the IPM.  We describe the challenges that existed in developing this model, including pre-breeding and skipped breeding periods where birds are unobservable, and breeding colony immigration.  We correlated posterior distributions for the parameters of interest to population growth rates. Variation in growth rate was most strongly correlated with immature survival, suggesting that factors at sea could be driving population trend.  Further IPM methods development, and more applications, are needed for species with complex life histories.”


Atlantic Yellow-nosed Albatross, photograph by Peter Ryan


Converse, S.J.,Horswill, C., Cuthbert, R.KJ., Oppel, A., Bond, A.L., Cooper, J. & Ryan, P.G. 2016.  Integrated population modeling for species with complex life histories: application to Atlantic Yellow-nosed Albatross. In: NAOC VI, North American Ornithological Conference. Bringing Science & Conservation Together.  Abstracts.  16-20 August; Washington, DC, USA.  pp. 86-87.

John Cooper, ACAP Information Officer, 25 August 2016

Saving species: eradicating invasive rats and cats on islands will prevent future losses of threatened vertebrates

Eight of every ten species extinctions has occurred on islands, and invasive mammals are the leading reason for those losses.  Currently, 40 percent of species at risk of global extinction are island inhabitants.

Erin McCreless (Department of Ecology and Evolutionary Biology, Long Marine Laboratory, University of California Santa Cruz, California, USA) and colleagues have published in the open-access online journal Nature Communications on the effects of invasive mammalian predators on island vertebrate populations (of which seabirds often form an important component).

The paper’s abstract follows:

“Invasive mammals on islands pose severe, ongoing threats to global biodiversity.  However, the severity of threats from different mammals, and the role of interacting biotic and abiotic factors in driving extinctions, remain poorly understood at a global scale.  Here we model global extirpation patterns for island populations of threatened and extinct vertebrates.  Extirpations are driven by interacting factors including invasive rats, cats, pigs, mustelids and mongooses, native species taxonomic class and volancy, island size, precipitation and human presence.  We show that controlling or eradicating the relevant invasive mammals could prevent 41–75% of predicted future extirpations.  The magnitude of benefits varies across species and environments; for example, managing invasive mammals on small, dry islands could halve the extirpation risk for highly threatened birds and mammals, while doing so on large, wet islands may have little benefit.  Our results provide quantitative estimates of conservation benefits and, when combined with costs in a return-on-investment framework, can guide efficient conservation strategies.”


Tristan Albatross chick under attack from introduced House Mice, photograph by Ross Wanless

See also a news report on the paper.


McCreless, E.E., Huff, D.D., Croll, D.A. Tershy, B.R., Spatz, D.R., Holmes, N.D., Butchart, S.H.M. & Wilcox, C.  2016.  Past and estimated future impact of invasive alien mammals on insular threatened vertebrate populations.  Nature Communications 7: 12488 DOI: 10.1038/NCOMMS12488.

John Cooper, ACAP Information Officer, 24 August 2016

Request for quotation: translation and conference interpretation service required for ACAP

A quotation is sought for the provision of translation and conference interpretation services for the Agreement on the Conservation of Albatrosses and Petrels (ACAP) Secretariat.

Two Light-mantled Sooty Albatrsses fly in unison, photograph by Aleks Terauds

The lowest quote will not necessarily be accepted.  Account will also be taken of a supplier’s proven ability to provide a high-quality service and to meet agreed deadlines.  Accordingly, information you provide in relation to these aspects will also be considered.

Quotations must be submitted prior to close of business (Hobart time, GMT +10) on Monday, 12 September 2016 to the This email address is being protected from spambots. You need JavaScript enabled to view it..  A detailed specification and quotation form for the work to be undertaken is available here.

Marco Favero, ACAP Executive Secretary, 23 August 2016

Grey Petrels can dive to 22 metres: significance for longline bycatch mitigation

Dominic Rollinson (Percy FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch, South Africa) and colleagues have published in the journal Emu Austral Ornithology on diving behaviour of ACAP-listed and Near Threatened Grey Petrels Procellaria cinerea breeding at Gough Island.

The paper’s abstract follows:

The Grey Petrel (Procellaria cinerea) is listed as Near Threatened globally owing to incidental mortality on long-line fishing gear and reduced breeding success on islands caused by the introduction of alien predators.  However, there are few studies of its foraging ecology and none of its diving behaviour.  We obtained data from temperature–depth recorders (n = 7 birds) and global positioning satellite trackers (n = 15) deployed on Grey Petrels breeding on Gough Island, South Atlantic Ocean.  Most birds foraged in the productive oceanic waters west or north-west of South Georgia.  Average maximum dive-depth was 3.2 ± 2.2 m with most dives <5 m (85%) and 95% of dives <7 m deep.  The maximum dive-depth (22 m) was deeper than previous measurements of dive-depth inProcellaria petrels, and maximum dive-duration also was longer than previously recorded inProcellaria petrels (at least 39 s). Individuals varied greatly in the mean number of dives per day (range 0.4–24.5).  Sex did not influence depth or duration of dives but sample sizes were small.  The time of day influenced dive-depth, and dives during daylight were, on average, deeper than dives at night, but the effect was weak; the maximum dive-depth at night was 17 m.  By providing insights into the diving behaviour of Grey Petrels our findings help to explain their high mortality on fishing long-lines.  We suggest that fisheries adopt bird-scaring lines that protect long-lines from scavenging seabirds during the setting process to a depth of at least 10 m, which could be achieved by increasing line-weighting or modifying bird-scaring lines, or both.  An understanding of the foraging ecology of commonly recorded by-catch species, such as Grey Petrels, is essential in the design of future devices to mitigate seabird by-catch in long-line fisheries.

Grey Petrel, photograph by Peter Ryan

With thanks to Barry Baker.


Rollinson, D.P., Dilley, B.J., Davies, D. & Ryan, P.G. 2016.  Diving behaviour of Grey Petrels and its relevance for mitigating long-line by-catch.  Emu

John Cooper, ACAP Information Officer, 22 August 2016

The Agreement on the
Conservation of Albatrosses and Petrels

ACAP is a multilateral agreement which seeks to conserve listed albatrosses, petrels and shearwaters by coordinating international activity to mitigate known threats to their populations.

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