The first translocated Hawaiian Petrel returns to Nihoku in May 2020, trail camera photograph by the Nihokū Ecosystem Restoration Project

ACAP Latest News has regularly reported on the efforts to establish a breeding colony of Endangered Hawaiian Petrels Pterodroma sandwichensis and Critically Endangered Newell’s Shearwaters Puffinus newellii at a lowland site protected by a predator-proof fence within the Kilauea Point National Wildlife Refuge on the Hawaiian island of Kauai.  Last year the first five Hawaiian Petrels that had been hand reared at Nihoku after translocation from the island’s mountainous interior were seen back prospecting at the site.  Now this year breeding has been confirmed for a single pair from the 2017 cohort that were first seen back at Nihoku in 2020. This season they laid an egg in June.  In addition, the first translocated Newell’s Shearwater has been back at the site this year

The fenced Nihoku restoration site from the air, photograph from the Nihokū Ecosystem Restoration Project

“After years at sea, the first ʻuaʻu, Hawaiian petrel, pair nests at Nihokū at Kīlauea Point National Wildlife Refuge. These birds are the first of 110 translocated ʻuaʻu chicks to return and nest at the fence-protected area of Nihokū.  In 2020, trail camera footage and biologists confirmed that five ʻuaʻu were returning to the site while prospecting the area for nesting, an early sign that the young birds that fledged from Nihokū successfully imprinted on the site and would likely soon return to breed.  In addition to the returning ʻuaʻu pair now breeding at Nihokū, the first prospecting ʻaʻo, Newell’s shearwater, was recently observed on trail cameras at the site, confirming that both species have successfully imprinted on the translocation site. The project is part of a larger, island-wide effort to restore populations of ʻuaʻu and ʻaʻo, both threatened and culturally important species.

“We are beyond thrilled to have confirmed breeding of the first Hawaiian petrel pair in a predator-free location, after six years of translocations.  This marks a major milestone towards the recovery of this imperiled species, and we hope that it is the first of many such announcements,” - Dr. Lindsay Young, Executive Director - Pacific Rim Conservation.

Read more here.

John Cooper, ACAP Information Officer, 22 July 2021

A dark-winged Amsterdam Albatross off Amsterdam Island, photograph by Kirk Zufelt

Svana Rogalla (Evolution and Optics of Nanostructures Group, Department of Biology, University of Ghent, Belgium) and colleagues have published in the Journal of the Royal Society Interface on a phylogenetic analysis and wind tunnel experiments to show that the dark wings of seabirds (including those of albatrosses and petrels) improve flight efficiency when undergoing radiative heating.

The paper’s abstract follows:

"Seabirds have evolved numerous adaptations that allow them to thrive under hostile conditions. Many seabirds share similar colour patterns, often with dark wings, suggesting that their coloration might be adaptive. Interestingly, these darker wings become hotter when birds fly under high solar irradiance, and previous studies on aerofoils have provided evidence that aerofoil surface heating can affect the ratio between lift and drag, i.e. flight efficiency. However, whether this effect benefits birds remains unknown. Here, we first used phylogenetic analyses to show that strictly oceanic seabirds with a higher glide performance (optimized by reduced sink rates, i.e. the altitude lost over time) have evolved darker wings, potentially as an additional adaptation to improve flight. Using wind tunnel experiments, we then showed that radiative heating of bird wings indeed improves their flight efficiency. These results illustrate that seabirds may have evolved wing pigmentation in part through selection for flight performance under extreme ocean conditions. We suggest that other bird clades, particularly long-distance migrants, might also benefit from this effect and therefore might show similar evolutionary trajectories. These findings may also serve as a guide for bioinspired innovations in aerospace and aviation, especially in low-speed regimes.”

Read an interview with the senior author of the study here.

With thanks to Janine Dunlop, Niven Librarian, FitzPatrick Institute of African Ornithology, University of Cape Town.

Reference:

Rogalla, S., Nicolaï, M.P.J., Porchetta, S., Glabeke, G., Battistella, C., D'Alba, L., Gianneschi, N.C., van Beeck, J. & Shawkey, N.D. 2021.  The evolution of darker wings in seabirds in relation to temperature-dependent flight efficiency.  Journal of the Royal Society Interface doi.org/10.1098/rsif.2021.0236.

John Cooper, ACAP Information Officer, 21 July 2021

Pink-footed Shearwater, watercolour by Lea Finke, from a photograph by Peter Hodum

The Tenth Meeting of ACAP’s Seabird Bycatch Working Group (SBG10) will be held as a virtual meeting from 17 to 19 August 2021 (AEST/UTC+10).  Likewise, the Sixth Meeting of the Population and Conservation Status Working Group (PaCSWG6) will be held virtually from 24 -25 August 2021 (AEST/UTC+10).  Most Documents and Information Papers are now available on this website for both meetings.  Please note some of the documents are protected by passwords; summaries of their contents are, however, available for reading.

Documents for the virtual Twelfth Meeting of the ACAP Advisory Committee (AC12) will be posted to this website in the three ACAP official languages of English, French and Spanish  before the end of this month. The meeting will be held from 30/31 August to 1/2 September 2021.

See AC12 Circular 5 for more details of this year’s virtual meetings, including meeting times.

ACAP Secretariat. 20 July 2021

Antipodean Albatross pair on Antipodes Island, photograph by Erica Sommer

Yvan Richards (Dragonfly Data Science) has produced a report for the Conservation Services Programme of the Department of Conservation on population modeling of the nominate subspecies of the New Zealand endemic Antipodean Albatross Diomedea antipodensis (globally Endangered) that breeds on Antipodes Island.  Annual survival rate and breeding success both decreased over the period 1984 to 2004.

The report’s summary follows:

Antipodean albatross Diomedea antipodensis antipodensis are endemic to New Zealand, with the quasi-totality of the population nesting on Antipodes Island. The species is classified as Nationally Critical due to a potential demographic decline. Threats to the population include incidental mortality in fisheries (in New Zealand and in international waters) and climate change.

The objective of this project was to provide a tool that allows stakeholders to explore the potential impact of threats and the demographic outcomes of management strategies. Using the tool, simulations of the demographic impact of different scenarios may be carried out so that management strategies can be assessed and prioritised.

A small subset of the population of Antipodean albatross has been studied since 1994, and these field data were used to perform the simulations. A Bayesian integrated population model was developed to estimate the main demographic parameters of the population. The model considered detectability of individuals, inter-annual variability, and movements in and out of the study area; it was fitted using the software Stan.

From the model, the annual survival rate for females was estimated to decline from 0.947 (95% c.i.: 0.914 – 0.974) in the period from 1994 to 2004, to 0.882 (95% c.i.: 0.814 – 0.94) after 2005. Estimated survival for males was higher, at 0.946 (95% c.i.: 0.913 – 0.972) and 0.927 (95% c.i.: 0.887 – 0.961) for the two periods. Breeding success also declined between the two periods, from 72.4% (95% c.i.: 65.8% – 78.6%) from 1994 to 2004 to 63.7% (95% c.i.: 53.4% – 73%) subsequently.

Under the current scenario, simulations suggest a significant decline of the population, with an annual growth rate of -4.84% (95% c.i.: -6.07% – -3.65%). Limitations in the data and in the model assumptions may cause the decline to be slightly overestimated; however, the trend remains of concerns.

The simulation tool is aimed to assist conservation managers with the prioritisation of management strategies to mitigate threats to the Antipodean albatross population and to guarantee the persistence of this species.:”

Reference:

Richard, Y. 2021.  Integrated Population Model of Antipodean Albatross for simulating Management Scenarios. Technical Report prepared for Department of Conservation – June 2021. Wellington: Dragonfly Data Science.  31 pp.

John Cooper, ACAP Information Officer, 19 July 2021