Short-tailed Shearwater at sea, photograph by Kirk Zufelt

Katherine Brownlie (School of Life and Environmental Sciences, Deakin University, Burwood, Australia) and colleagues have published in the journal Emu - Austral Ornithology on using acoustic loggers in Short-tailed Shearwaters Ardenna tenuirostris colonies to estimate breeding information.

The paper’s abstract follows:

“Establishing appropriate conservation management objectives and actions for seabirds requires timely detection of changes in their populations.  However, obtaining regular accurate measures of seabird population size and trends can be difficult due to logistical and financial constraints in accessing remote breeding sites.  The Short-tailed Shearwater (Ardenna tenuirostris) is a wide-ranging, burrow-nesting Procellariiform [sic] with an estimated breeding population size of ca 23 million individuals.  Despite its ecological significance, there is currently limited monitoring of the species. In the present study, eight acoustic data loggers were deployed across six sites over two breeding seasons to assess the efficacy of acoustic monitoring.  Five acoustic indices were used to investigate vocal activity over the breeding season, detect phenology events, and to determine the most accurate period to assess the density of occupied nests.  The general pattern over the breeding season was similar for several of the acoustic indices and reflected colony attendance patterns. Linear regressions fitted to the normalised difference soundscape index values and density of occupied nests (burrows·m⁻²) revealed significant relationships in both the incubation and chick-rearing.  The results suggest that passive acoustic monitoring could be used as an effective method to predict nesting density in Short-tailed Shearwater breeding colonies.  Used in conjunction with information on the breeding colony area, this could enable regular estimates of colony population size. Such information is crucial for the early detection of population trajectory changes. The method may also be applicable for other burrow- or surface-nesting seabirds for which regular wide-spread monitoring currently proves difficult.”

Reference:

Brownlie, K.C., Monash, R., Geeson, J.J., Fort, J., Bustamante, P. & Arnould, J.P.Y. 2020.  Developing a passive acoustic monitoring technique for Australia’s most numerous seabird, the Short-tailed Shearwater (Ardenna tenuirostris).  Emu - Austral Ornithology, DOI: 10.1080/01584197.2020.1732828.

John Cooper, ACAP Information Officer, 13 May 2020

Dimas Gianuca (left) and Gabriel Canani (Projeto Albatroz/ATF) holding their WAD2020 banner on the shore with the South West Atlantic as background, photograph by Mariana Scain Mazzochi

With the COVID-19 pandemic seemingly shutting down the whole world, this year’s inaugural World Albatross Day is no exception in facing disruption to its planning.  Several countries have had to cancel events set to mark the day and it looks like ‘WAD2020’ is going to have to be a strictly ‘virtual’ event come 19 June.

As part of its efforts to raise awareness of World Albatross Day, ACAP Latest News approached the five national teams of BirdLife International’s Albatross Task Force to make and then photograph a WAD2020 banner out at sea on a fishing vessel.  Getting in early, the ATF teams in Chile and South Africa took their banners out to sea to be photographed aboard fishing trawlers.  Then along came coronavirus with its accompanying social distancing, self-isolation and lockdowns.  In Argentina, with no fishing vessels heading out the ATF team had to resort to photographing their banner at home.  Much the same problem in Brazil as ATF Leader Dimas Gianuca of the NGO Projeto Albatroz writes to ALN:

“Bad weather prevented going outside for a good picture in the last two days.  I was tempted to take a picture at home, but that would not be fair having the South-West Atlantic as a backyard”.  Not being able to gain access to a fishing harbour, let alone out to sea on a fishing vessel, Dimas and colleagues took their banner to the seaside: “We are at Cassino Beach, Rio Grande, in southernmost Brazil, where Atlantic Yellow-nosed and Black-browed Albatrosses and giant petrels can be spotted from the shore during winter - not mentioning the Magellanic Penguins and fur seals on the beach.”

Dimas goes on to describe their work with Projeto Albatroz and ATF:

“Projeto Albatroz currently work across four ports, from north to south: Itaipava (ES), Cabo Frio (RJ), Itajaí (SC) and Rio Grande (RS).  Rio Grande (30ºS) and Itajaí (26º), the two most southerly Brazilian ports, harbour the southern Brazilian pelagic longline fleet, which operates in waters with high densities of albatrosses and petrels. Projeto Albatroz and the ATF have worked extensively with this fleet mapping seabird bycatch, developing mitigation measures and supporting public policies to reduce seabird mortality. Extensive at-sea trials have been conducted over the last 15 years, with the voluntary collaboration of fishers, including research on mitigation measures such as bird-scaring lines (left), line-weighting, night setting (right) and Hookpods, which have contributed to guiding national and international policies.”

Dimas Gianuca (left) on a Brazilian longliner

ACAP Latest News asks all ATF members to take care and stay safe in these difficult times.

Projeto Albatroz is sponsored by Petrobrás through the "Programa Petrobrás Socio-Ambiental" and supported by BirdLife/RSPB through the Albatross Task Force Programme.

With thanks to Dimas Gianuca.

John Cooper, ACAP Information Officer, 12 May 2020

Short-tailed Albatrosses gather around  a chick on Mukojima

Mukojima (commonly known as Keta Island) is located in the northernmost part of the Japanese Ogasawara (Bonin) Islands south of Japan and about 60 km north of the inhabited island of Chichijima.  With an area of 2.6 km², it is the largest island of the Mukojima Island Group, which is made up of four main islands, along with smaller islets and rocks.  From the end of 1800s the island was inhabited by cattle ranchers and farmers, but since 1944 the island has been mostly uninhabited.  The highest point reaches 88 m in the eastern part, but the island is mainly flat.

Mukojima from the sea

After residents left Mukojima, feral Domestic Goats Capra aegagrus hircus seriously damaged the once mainly forested island that supported endemic invertebrates and plants, resulting in severe vegetation loss and erosion.  The Tokyo Metropolitan Government (TMG) undertook an eradication programme from 1998 for four years that removed 940 goats from Mukojima.  It also managed to eradicate the Black Rat Rattus rattus from the island by 2009.  Today, the island is mostly a dry grassland with a few small forested patches near the shoreline.

A view of Mukojima

Three North Pacific albatross species breed on Mukojima: Black-footed Phoebastria nigripes, Laysan P. immutabilis (both Near Threatened) and the globally Vulnerable Short-tailed P. albatrus.  The Black-footed Albatross is the most abundant species of the three, producing over 50 fledglings in recent years.  On an islet called Mukotori-shima, just off Mukojima, there are about 200 fledglings produced.  In the whole Mukojima Island Group about 1000 Black-footed Albatrosses fledge each year from five islands (Mukojima, Mukotori-shima, Nakodojima, Nakodojima-torishima and Yomejima – all uninhabited).  The total number has been increasing, almost doubling in the last 15 years.

Black-footed Albatross on Mukojima

The Mukojima Island Group is the only breeding site for Laysan Albatrosses in the western North Pacific.  In 2013 there were 11 occupied nests on Mukojima, with 15 on Mukotori-shima and one on Yomejima.  Unlike for Black-footed Albatrosses, Laysan Albatross numbers have shown no discernable trend in recent years.  The number of chicks fledging varied from five to 19 a year from 1990 to 2013.  Monitoring and banding studies have been conducted by the TMG and the Institute of Boninology since 2004.

Mukojima is best known as a translocation site for the Short-tailed Albatross.  Over five years from 2008 to 2012 70 Short-tailed Albatross chicks were translocated from Torishima – the species’ main breeding site - to Mukojima, where they were hand fed until 69 of them fledged.  The aim was to create a new colony on an island not at risk to volcanic activity, as is Torishima.  Some of the hand-reared individuals have come back to the island and started to breed.  One pair has been successfully breeding on the island, and as of 2020, two individuals that have fledged naturally from Mukojima have been seen to return to the island.  The translocation project was conducted by the US Fish and Wildlife Service, Japanese Ministry of the Environment, and the Yamashina Institute for Ornithology (YIO). The breeding and behaviour of the Short-tailed Albatrosses on Mukojima have been monitored by the TMG and YIO since 2012.  Access ACAP Latest News posts about the translocation project here.

Short-tailed Albatross chick on Mukojima, photograph by T. Minami

A Short-tailed Albatross chick fledged from uninhabited and now goat-free Nakodojima, five kilometres away from from Mukojima, in 2014; an island where approaching a thousand Black-footed Albatrosses also breed (click here).

The Ogasawara Islands were designated as a World Heritage Natural Site in 2011.

References:

Deguchi, T., Sato, F., Eda, M., Izumi, H., Suzuki , H., Suryan, R.M., Lance, E.W., Hasegawa, H. & Ozaki, K. 2016  Translocation and hand-rearing result in short-tailed albatrosses returning to breed in the Ogasawara Islands 80 years after extirpation.  Animal Conservation 20: 341-349.

Government of Japan 2010.  Nomination of the Ogasawara Islands for Inscription on the World Heritage List.  [Tokyo]: Government of Japan.  228 pp.

Horikoshi, K., Suzuki, H. & Chiba, H. 2015.  Breeding status of Laysan Albatross in Mukojima Island Group.  Ogasawara-Kenkyu-Nenpo (Annual Report of Ogasawara Research) 38: 51-64 (in Japanese).

Ministry of the Environment 2009.  Management Plan for the Ogasawara Islands World Natural Heritage Nominated Site (Draft).  Tokyo: Ministry of the Environment.  31 pp. [in Japanese].

The Mukojima Short-tailed Albatross translocation site is on the centre horizon, photographs by Teru Yuta

Teru Yuta, Yamashina Institute for Ornithology, Japan & John Cooper, ACAP Information Officer, 11 May 2020

In recent years a few pairs of globally Near Threatened Laysan Albatrosses Phoebastria immutabilis have attempted to breed on the north coast of the Hawaiian island of Oʻahu at Kahuku Point (also known as Kalaeokaunaʻoa).  However, it was only in the 2018/19 season after years of failed attempts that three chicks fledged from the seven eggs laid, a success attributed to reduced disturbance (click here).

With advice from Dr Sheldon Plentovich, U.S. Fish & Wildlife Service’s Pacific Islands Coastal Program Coordinator, the North Shore Community Land Trust has taken up the stewardship of guarding the breeding birds against disturbance and improving their habitats as part of its mission from 1997 “to protect, steward, and enhance the natural landscapes, cultural heritage, and rural character of ahupuaʻa (land divisions) from Kahuku (Oʻahu’s northernmost point) to Kaʻena (Oʻahu’s westernmst point)”.

Following an approach to the trust, its Executive Director, Adam Borrello, has replied  to ACAP Latest News in support of this year’s inaugural World Albatross Day: “As we remove invasive species and clear the way for more natives to thrive, the coastal strand habitat at Kahuku Point is returning to a more pristine condition.  We see the presence of the albatross as their endorsement of our restoration efforts in an area more resistant to sea level rise than the majority of their current habitat.  Ensuring the safety of the chicks, so that they can successfully fledge, is the culmination of a great deal of hard work and cooperation.  We are honoured to steward this land and are excited for the future of this growing colony.”

The North Shore Community Land Trust’s ‘WAD2020’ sign near a Laysan Albatross chick at Kahuku Point, sign and photograph by Alice Terry

With COVID-19 restrictions in Hawaii halting both a planned World Albatross Day banner display with local school children at Kahuku Point this month and the making of a professional-looking banner, the Trust did the next best thing and took along a hand-illustrated sign on a clipboard to photograph with one of the 2019/20 season’s chicks.  This season with the improved protection from the Trust breeding numbers have increased to nine pairs, from which three chicks currently survive.

With thanks to Adam Borrello, Executive Secretary and Alice Terry, Outreach & Volunteer Coordinator, North Shore Community Land Trust and Dr Sheldon Plentovich, Pacific Islands Coastal Program Coordinator, U.S. Fish & Wildlife Service.

John Cooper, ACAP Information Officer, 10 May 2020