The Shiant Isles are a group of privately-owned islands in the Outer Hebrides of Scotland.  The three main islands in the group total c. 220 ha.  The Shiants support large seabird populations, including Northern or Arctic Fulmars Fulmarus glacialis and Atlantic Puffins Fratercula arctica (65 200 pairs representing 10% of the UK’s population).  Also present on the isles since about 1900 are Black or Ship Rats Rattus rattus which have been shown to include Shiant seabirds in their diet, obtained either (or both) by predation or scavenging.

Shiant Isles

The Shiants Seabird Recovery Project now aims to eradicate the islands’ rats, inter alia in the hope of allowing Manx Shearwaters Puffinus puffinus and European Storm Petrels Hydrobates pelagicus to commence breeding, for which there is some evidence of previous occurrence for at least the former species.

Manx Shearwater, photograph by Nathan Fletcher

“Plans to tackle the menace have been given a boost after £450,000 of European Union funding [under the LIFE+ programme, the European Union's environment fund] was awarded … to the Shiant Seabird Recovery Project.  Scottish Natural Heritage is providing £200 000 and the remainder will be raised from donations.  The project will use recordings of calls to attract the birds and will carry out active management to make sure the birds have the best opportunity to settle and breed” (click here).

“Following substantial research and consultation with specialists, an operational plan is being developed to eradicate the rats in the safest and most effective way, with the lowest risk of impacting native species, by laying poison in bait stations around the island” (click here).

The project to remove the rats is a partnership between RSPB Scotland, Scottish Natural Heritage

and the Nicolson family, owners and custodians of the Shiants.

“In April 2012 a survey of the Shiants estimated there to be around 3,600 rats on the islands. This number increases significantly in the summer months when more food is available.  A study in 1998 found that 68% of the rats captured there had consumed feathers and quills.  The presence of Manx shearwaters on the islands historically is supported both by the abundance of suitable nesting habitat, and the discovery by archaeologists of Manx shearwater bones in a 17th- and 18th-century midden heap on one of the islands.  Evidence gathered from around the world demonstrates that the absence of shearwaters and storm petrels on the Shiants can be attributed to the presence of rats.  The eradication approach in the Shiants has proven successful on a number of UK islands, including Canna, Ramsey and Lundy. Since the eradication of rats on Lundy, in the Bristol Channel, Manx shearwater numbers on the island have increased tenfold… ” (click here).

Click here to read about improving breeding habitat for Manx Shearwaters and European Storm Petrels by the successful removal of rats from the United Kingdom’s Scilly Isles.

With thanks to Chris Pollard for information.

Selected Literature:

Nicolson, A. 2001.  Sea Room an Island Life.  London: HarperCollins Publishers.  391 pp.

John Cooper, ACAP Information Officer, 13 June 2014, updated 22 June 2014

David Ainley (H.T. Harvey & Associates Ecological Consultants, Los Gatos, California, USA) and colleagues have published in the open-access journal Marine Ornithology on stomach analyses of fledgling Newell’s Shearwaters Puffinus newelli found beneath power lines on the Hawaiian island of Kaua’i.

Newell's Shearwater, photograph by Eric Vanderwwerf

The Endangered shearwater’s diet was dominated by ommastrephid squid, although it appears digestion had reduced the role of some other prey species, notably flying fish Exocoetus spp.. The paper concludes:  “Much remains to be learned about the at-sea ecology of the Newell’s Shearwater and how it is affected by fishing, a task made increasingly difficult owing to the continued steep decline in this species’ population on Kaua’i and elsewhere in Hawai’i.”

Reference:

Ainley, D.G., Walker, W.A., Gregory C. Spencer, G.C. & Holmes, N.D. 2014.  The prey of Newell’s Shearwater Puffinus newelli in Hawaiian waters.  Marine Ornithology 44: 69-72.

John Cooper, ACAP Information Officer, 12 June 2014

An aerial census by helicopter in January 2014 has revealed that Disappointment Island in New Zealand’s Auckland Islands supported 452 breeding pairs of Gibson’s Antipodean Albatrosses Diomedea antipodensis gibsoni.

Disappointment Island, photograph by Barry Baker

Gibson's Antipodean Albatross on the Auckland Islands

Photograph by Colin O'Donnell

The photographic survey was undertaken on behalf of the New Zealand Department of Conservation by Latitude 42, an environmental consultancy based in Tasmania.

Click here to read of helicopter-bourne aerial censuses of another species of great albatross, the Wandering D. exulans of South Africa's uninhabited Prince Edward Island. 

Reference:

Baker, G.B. & Jensz, K. 2014.  Gibson’s albatross at Disappointment Island - analysis of aerial photographs. Report prepared for Department of Conservation.   [Kettering]: Latitude 42 Environmental Consultants Pty Ltd.   7 pp.

John Cooper, ACAP Information Officer, 11 June 2014

Scott Shaffer (Department of Biological Sciences, San José State University, San Jose, California, USA) and colleagues write in the open-access electronic journal PLoS ONE use miniature loggers in artificial eggs to investigate egg-turning in Laysan Albatrosses Phoebastria immutabilis and two other seabird species.

The paper’s abstract follows:

“Egg turning is unique to birds and critical for embryonic development in most avian species.  Technology that can measure changes in egg orientation and temperature at fine temporal scales (1 Hz) was neither readily available nor small enough to fit into artificial eggs until recently.  Here we show the utility of novel miniature data loggers equipped with 3-axis (i.e., triaxial) accelerometers, magnetometers, and a temperature thermistor to study egg turning behavior in free-ranging birds.  Artificial eggs containing egg loggers were deployed in the nests of three seabird species for 1–7 days of continuous monitoring.  These species (1) turned their eggs more frequently (up to 6.5 turns h⁻¹) than previously reported for other species, but angular changes were often small (1–10° most common), (2) displayed similar mean turning rates (ca. 2 turns h⁻¹) despite major differences in reproductive ecology, and (3) demonstrated distinct diurnal cycling in egg temperatures that varied between 1.4 and 2.4°C.  These novel egg loggers revealed high-resolution, three-dimensional egg turning behavior heretofore never measured in wild birds.  This new form of biotechnology has broad applicability for addressing fundamental questions in avian breeding ecology, life history, and development, and can be used as a tool to monitor birds that are sensitive to disturbance while breeding.”

A Laysan Albatross pair changes over incubation duties

Photograph by Bob Waid

Reference:

Shaffer, S.A., Clatterbuck, C.A., Kelsey, E.C., Naiman, A.D., Young, L.C., Vanderwerf, E.A., Warzybok, P., Bradley, R., Jahncke, J. & Bower, G.C. 2014.  As the egg turns: monitoring egg attendance behavior in wild birds using novel data logging technology.  PLoS ONE 9(6): e97898.  doi:10.1371/journal.pone.0097898.

John Cooper, ACAP Information Officer, 10 June 2014