Artificial burrows for Cory's Shearwaters with decoys and a solar-powered sound system on Corvo, Azores, photograph by Steffen Oppel

Nuno Oliveira (Sociedade Portuguesa para o Estudo das Aves (SPEA), Lisbon, Portugal) and colleagues have published in the journal Airo on Cory’s Shearwater Calonectris borealis utilizing artificial burrows.

The paper’s abstract follows:

“Seabirds are one of the avian groups facing the fastest and highest decline in population numbers around the world, suffering from many threats not only at sea but also on land.  For burrow-nesting seabirds, the loss of adequate breeding habitat, human disturbance and competition with other species make the availability of adequate nesting burrows a limiting factor for the recovery of breeding numbers.  Artificial nest provisioning has been broadly used as a measure to invert population declines, by increasing the availability of higher quality nests. Berlengas Archipelago holds an important breeding population of Cory’s Shearwater Calonectris borealis, mainly concentrated in two different sites, Farilhão Grande Islet and Berlenga Island.  On Berlenga Island, artificial nests have been provided since the late 1980’s.  In this study, we present the results of artificial nest provisioning as a conservation measure implemented over almost 30 years and its effectiveness in inverting a negative population trend found in Farilhão Grande Islet.  We also present up-to-date data on the population size and breeding parameters of Cory´s Shearwater nesting in Berlengas Archipelago.  Breeding success was found to be higher in artificial nests (0.86 ± 0.05) than in natural nests (0.77 ± 0.12). Occupation rate for artificial nests built after 2015 increased along the first 4 years after installation, resulting in an annual growth rate of 9%.  In 2015, 32-34% of the Cory’s Shearwater population was breeding in artificial nests.  A total of 681 active nests were counted along the entire archipelago in 2015, with an estimate of 800 – 975 breeding pairs. In Farilhão Grande, breeding success was particularly low and the breeding population showed a significant negative trend (annual growth rate of -2% since 2005).  However, demographic modelling indicates that a decrease on productivity by itself may not explain the observed negative population growth, and that other factors (e.g., adult survival) may be driving the negative trend. The identification of demographic par9ameters responsible for such changes will provide relevant information for conservation managers and authorities on the proper solutions to put in place. Artificial nests were shown to be an effective conservation measure for Cory’s Shearwater on Berlenga Island, and may thus contribute to the increase of breeding success and of the breeding population size at Farilhão Grande islet.”

The Cory's Shearwater 'hotel', and the anti-predator fence on Corvo in the Azores, photograph by Steffen Oppel

Read a related post on artificial burrows for Cory’s Shearwaters here.

Reference:

Oliveira, N., Abreu, Bores, J., Fagundes, A.I., Alonso, H. & Andrade, J. 2020.  Evaluating the potential of artificial nests as a conservation measure for Cory’s Shearwaters Calonectris borealis breeding in Berlengas Archipelago, Portugal.  Airo 27: 3-19.

John Cooper, ACAP Information Officer, 18 April 2020

The Edward Grey Institute of Field Ornithology (EGI) is based in the Department of Zoology, University of Oxford, UK.  Founded in 1937, the Institute conducts research into the behaviour, ecology, evolution and conservation of birds, with a strong emphasis on understanding organisms in their natural environments.  It is particularly well known for its long-term population studies, and as one of the birthplaces of behavioural ecology.  The Institute’s Alexander Library of Ornithology is described as one of the foremost ornithological reference libraries in the world.

Ben Sheldon, Director, Edward Grey Institute

ACAP Latest News reached out to the EGI’s Director and Luc Hoffmann Chair of Ornithology, Professor Ben Sheldon, to gain the Institute’s support for the inaugural World Albatross Day on 19 June.  He writes in return: “Recent scientific advances have shown us that albatrosses range over vast stretches of the world’s oceans while seeking food.  These remarkable global travellers are also increasingly threatened in their natural environments.  World Albatross Day raises the awareness of this unique and imperilled group of birds.”

With this welcome support the EGI joins two other prestigious ornithological institutes in recognizing ‘WAD2020’: the FitzPatrick Institute of African Ornithology at the University of Cape Town, South Africa and the Yamashina Institute for Ornithology in Japan.

With thanks to Ben Sheldon.

John Cooper, ACAP Information Officer, 17 April 2020

Kath Walker (left) and Graeme Elliott with their World Albatross Day banner behind an adult non-breeding male Antipodean Albatross - who walked into the frame

Five sub-Antarctic island groups south of New Zealand form a single World Heritage Site, proclaimed in 1998.  With a recent expedition to Antipodes Island they are now linked by having a World Albatross Day banner displayed on all five of them this austral summer.

Previously ‘WAD2020’ banners have been taken to and photographed with albatrosses on the Auckland, Bounty, Campbell and Snares Islands.

On their visit to the Antipodes, cut short by COVID-19 travel restrictions, Graeme Elliott and Kath Walker, scientists with the New Zealand Department of Conservation (DOC), took along a home-made banner to be photographed with a globally Endangered and Nationally Critical Antipodean Albatross Diomedea antipodensis.  Although their originally planned six-week trip was cut down to nine working days ashore, it was still possible for them to fit GPS satellite transmitters to 40 Antipodean Albatrosses, mostly young female pre-breeders.  “We actually had another 20 satellite tags but they had been intended from the start (and programmed accordingly) for a long-term deployment on fledglings.  Due to our very late arrival on the island, all the chicks had long since fledged, so we held onto those in the hope we can deploy them on the 2020 season chicks instead.”  Tracking maps are already being generated showing the birds moving up to 6000 km (click here).

Following their shortened expedition, Kath Walker and Graeme Elliott have written to ACAP Latest News: “Those quintessential Southern Ocean birds – albatrosses - need our help.  By directing and focusing effort, World Albatross Day is an invaluable initiative”

Antipodes Island is now mouse free following a successful eradication project in 2016 led by DOC.  Heartening then to hear from Kath Walker that on the island “endemic flies and moths [have] exploded in numbers … and we still hope will increase megaherb numbers due to improved pollination”.

The Antipodean Albatross is listed on Appendices I and II of the Convention for Migratory Species.  The Antipodes Island nominate population has been recognised since 2017 as a population of conservation concern by ACAP.

Read more about the tracking work with Antipodean Albatrosses here.

With thanks to Kath Walker.

Antipodean Albatross by ABUN artist Lea Finke, from a photograph by Kirk Zufelt

John Cooper, ACAP Information Officer, 16 April 2020

Light-mantled Albatrosses at the Auckland Islands, by ABUN artist Annie Shoemaker-Magdaleno from a photograph by Colin O'Donnell 

Rebecca French (Charles Perkins Centre, School of Life and Environmental Sciences, The University of Sydney, Australia) and colleagues have published in the ornithological journal Notornis on historical trends of birds, including ACAP-listed seabirds, on sub-Antarctic Enderby Island south of New Zealand.

The paper’s abstract follows:

“Enderby Island is a much-visited small island in the New Zealand subantarctic, and is an important area for birdlife.  However, despite this, the bird community of Enderby Island has never been systematically described.  We summarise bird records on Enderby Island from 1840 to 2018.  Using these data we describe the bird community with an emphasis on resident species, and compare the frequency of sightings before and after eradication of invasive mammals in 1993.  We also investigate trends in bird sightings from 1992 to 2018. There was a significant increase in the sightings of some species, including tui (Prosthemadera novaeseelandiae) and silvereye (Zosterops lateralis), and a significant decrease in others, including white-fronted tern (Sterna striata). Some species, such as New Zealand falcon (Falco novaeseelandiae) and Auckland Island snipe (Coenocorypha aucklandica aucklandica), have recovered successfully following dramatic historical declines.  We hypothesise that these trends in sightings are driven by changes in human exploitation, the introduction and subsequent eradication of browsing mammals and mice, changes in the abundance and structure of the invertebrate community, and changes in vegetation cover.  However, we believe that trends in sighting rates of southern royal albatross (Diomedea epomophora) may be an artefact of changes in visitor behaviour following the construction of a boardwalk, rather than changes in the species’ abundance.”

Southern Royal Albatrosses on Enderby Island, photograph by Barry Baker

This publication forms part of a compilation of 19 papers appearing in a special issue of the journal Notornis of Birds New Zealand that covers many aspects of the avifauna of the Auckland Islands.  The special issue is also being made available as a 436-page book with the title Lost Gold: Ornithology of the subantarctic Auckland Islands.  Edited by Colin Miskelly and Craig Symes, it can be ordered for purchase (click here).  An interview with the two editors gives information about their work with the book.  Click here to access abstracts for all 19 papers.

With thanks to Colin Miskelly, Museum of New Zealand Te Papa Tongarewa.

Reference:

French, R.K., Miskelly, C.M., Muller, C.G., Russ, R.B., Taylor, G.A., & Tennyson, A.J.D. 2020.  Birds of Enderby Island, Auckland Islands, New Zealand subantarctic.  Notornis 667: 189-212.

John Cooper, ACAP Information Officer, 15 April 2020