White-capped Albatross by ABUN artist Lee Finke for ACAP; after a photograph by Graham Parker

Graham Parker (Parker Conservation) and colleagues have reported to New Zealand’s Department of Conservation via its Conservation Services Programme (CSP) on field work carried out over 2021/22 on Antipodean Diomedea antipodensis gibsoni and White-capped Thalassarche Albatrosses on the sub-Antarctic Adams and Disappointment Islands, Auckland Islands group.

The report’s summary follows:

“This report details the mark-recapture methods and findings for Gibson’s albatross and white-capped albatross at the Auckland Islands.  We present data on the size of the Gibson’s albatross nesting population on Adams Island in 2022 and update estimates of survival, productivity, and recruitment and foraging range to help identify causes of current population size and trends.  For white-capped albatrosses the focus is on estimating adult survival, documenting a study set up to quantify productivity, and drone trials to assess the suitability of drones for quantifying the breeding population size.

Gibson’s albatross. The survival rate of adult females and males has recuperated somewhat from the dramatically low survival rates recorded 2006–08.  However, at 92% the 10-year average survival rate for both sexes remains 4% lower than before the population crash in 2005, and is probably incompatible with population recovery given limited chick production.  Nesting success and chick production for the 2020 and 2021 cohorts could not be determined since we could not visit the island in 2021.  Mark-recapture models have shown a gradual but steady continuing decline in the Gibson’s albatross breeding population.  This is now starting to be reflected in the trend of nest counts as well: estimated island-wide nest numbers showed slow improvement 2008–13, but these gains have stalled with a current growth rate or lambda of 1.1.  The island-wide estimate of Gibson’s albatross nests in 2021–22 (4,434 nests) remains half the size of the pre-crash nesting population.  Transmitting GPS trackers were fitted on 39 breeding birds, along with 23 GLS loggers.  Together, survival, breeding numbers and recruitment show the slow Gibson’s albatross population recovery recorded over the decade 2007–16 has stalled.

White-capped albatross. Banded white-capped albatrosses were resighted at a rate of 0.25 in the study colony of 679 banded birds.  Adult survival was estimated as 89% (95% CI 86–91), taking into account different detection rates of nesting birds and those not on nest during colony visits.  This is similar to but more precise than the last estimate in 2020 (90%, 86–93).  Ten nest cameras were deployed to take time-lapse images of 61 active nests, which should provide data on productivity and refine our understanding of breeding-season timings.  Drone trials indicate that animal responses to a small drone are minimal, and the photographs obtained from programmed-grid overflight at 30–70 m over nests are suitable for counting apparently nesting birds.  Nest contents of apparently nesting birds were also quantified and whole-colony ground counts conducted, illustrating that ease of fitting in drone survey—and the ground-truthing needed to refine the accuracy of later counts from images—around other colony work.”

Access a Power Point presentation by the authors on their research from here.

Reference:

Parker, G.C., Elliott, G., Walker, K. & Rexer-Huber, K. 2022.  Gibson’s albatross and white-capped albatross in the Auckland Islands 2021–22.  Dunedin: Parker Conservation.  26 pp.

John Cooper, ACAP News Correspondent, 06 September 2022

A Manx Shearwater in flight; photograph by Joe Pender

James A. Kempton (Department of Biology, University of Oxford, United Kingdom) and colleagues have published open access in Science Advances on a new metric demonstrating Manx Shearwaters’ utilisation of dynamic soaring and corresponding distribution at sea.

The paper’s abstract follows:

“Dynamic soaring harvests energy from a spatiotemporal wind gradient, allowing albatrosses to glide over vast distances. However, its use is challenging to demonstrate empirically and has yet to be confirmed in other seabirds. Here, we investigate how flap-gliding Manx shearwaters optimize their flight for dynamic soaring. We do so by deriving a new metric, the horizontal wind effectiveness, that quantifies how effectively flight harvests energy from a shear layer. We evaluate this metric empirically for fine-scale trajectories reconstructed from bird-borne video data using a simplified flight dynamics model. We find that the birds’ undulations are phased with their horizontal turning to optimize energy harvesting. We also assess the opportunity for energy harvesting in long-range, GPS-logged foraging trajectories and find that Manx shearwaters optimize their flight to increase the opportunity for dynamic soaring during favorable wind conditions. Our results show how small-scale dynamic soaring affects large-scale Manx shearwater distribution at sea.”

REFERENCE:

Kempton, J.A., Wynn, J., Bond, S., Evry, J., Fayet, A.L., Gillies, N., Guilford, T., Kavelaars, M., Juarez-Martinez, I., Padget, O., Rutz, C., Shoji, A., Syposz, M., Taylor, G.K. 2022. Optimization of dynamic soaring in a flap-gliding seabird affects its large-scale distribution at sea. Science Advances. https://doi.org/10.1126/sciadv.abo0200

Posted 5 September 2022

Laysan Albatrosses Phoebastria immutabilis breed among washed-up plastic litter on Midway Atoll; photograph by Steven Siegel, Marine Photobank

The Albatross and Petrel Agreement has chosen “Plastic Pollution” as its theme to mark the fourth World Albatross Day, to be celebrated on 19 June 2023.  This follows the inaugural theme “Eradicating Island Pests” in 2020, “Ensuring Albatross-friendly Fisheries” in 2021 and “Climate Change” in 2022.

Albatrosses are affected by a range of pollutants, of which plastics, whether ingested and then fed to chicks or causing entanglements, are certainly the most visible and well known to the general public.  However, albatrosses face other significant pollutants, including heavy metals, (such as mercury) and POPs (persistent organic pollutants, such as insecticides).  ACAP will therefore include these and other categories of pollutants along with plastics in promoting “WAD2023”.

A 500-ml plastic bottle found in the stomach of a Southern Royal Albatross Diomedea epomophora (click here); photograph from the New Zealand Department of Conservation

Two new albatross species will be used to feature the theme for next year’s World Albatross Day, with artworks, posters, infographics and a music video.  These will be the globally Endangered Northern Royal Albatross D. sanfordi, endemic to New Zealand, and the abundant and widespread Black-browed Albatross Thalassarche melanophris.  In addition, coverage will be given to last year’s featured species, the Black-footed Phoebastria nigripes and Laysan P. immutabilis Albatrosses of the North Pacific, which ingest more plastic than do the southern hemisphere species.

A beached juvenile Black-browed/Campbell Albatross entangled by a plastic string attached to a balloon, Dolphin Point, New South Wales, Australia (click here); photograph from Karen Joynes

As well as the world’s 22 species of albatrosses, other procellariforms are prone to ingest pieces of plastic found floating on the sea surface and mistaken as food.  A notable example is the Flesh-footed Shearwater Ardenna carnepeis, shown to ingest very large amounts of plastic at one breeding locality at least (click here).  This shearwater is a species that has previously been identified as a potential candidate for ACAP listing (click here).

Heavy load: plastic being removed from the stomach of a Flesh-footed Shearwater; photograph by Ian Hutton

ACAP is giving consideration to promoting WAD2023 by running one or two competitions for public participation, including for children.  The competitions held for the inaugural World Albatross Day proved popular, so follow ACAP Latest News and social media for announcements in due course.

John Cooper, ACAP News Correspondent, 01 September 2022