A banking Wandering Albatross, artwork with coloured pencils for ACAP by Milena A. Maira Marchesse

Stefan Schoombie (FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch, South Africa) and colleagues published in 2019 in the Journal of Field Ornithology on detecting bank angles of globally Vulnerable Wandering Albatrosses Diomedea exulans in flight with bird-borne video cameras.

The paper’s abstract follows:

“The use of miniaturized video cameras to study the at-sea behavior of flying seabirds has increased in recent years. These cameras allow researchers to record several behaviors that were not previously possible to observe. However, video recorders produce large amounts of data and videos can often be time-consuming to analyze. We present a new technique using open-source software to extract bank angles from bird-borne video footage. Bank angle is a key facet of dynamic soaring, which allows albatrosses and petrels to efficiently search vast areas of ocean for food. Miniaturized video cameras were deployed on 28 Wandering Albatrosses (Diomedea exulans) on Marion Island (one of the two Prince Edward Islands) from 2016 to 2018. The OpenCV library for the Python programming language was used to extract the angle of the horizon relative to the bird’s body (= bank angle) from footage when the birds were flying using a series of steps focused on edge detection. The extracted angles were not significantly different from angles measured manually by three independent observers, thus being a valid method to measure bank angles. Image quality, high wind speeds, and sunlight all influenced the accuracy of angle estimates, but post-processing eliminated most of these errors. Birds flew most often with cross-winds (58%) and tailwinds (39%), resulting in skewed distributions of bank angles when birds turned into the wind more often. Higher wind speeds resulted in extreme bank angles (maximum observed was 94°). We present a novel method for measuring postural data from seabirds that can be used to describe the fine-scale movements of the dynamic-soaring cycle. Birds appeared to alter their bank angle in response to varying wind conditions to counter wind drift associated with the prevailing westerly winds in the Southern Ocean. These data, in combination with fine-scale positional data, may lead to new insights into dynamic-soaring flight.”

With thanks to Janine Schoombie.

Reference:

Schoombie, S., Schoombie, J., Brink, C.W., Stevens, K.L., Jones, C.W., Risi, M.M. & Ryan, P.G. 2019.  Automated extraction of bank angles from bird-borne video footage using open-source software.  Journal of Field Ornithology 90: 361-372.

John Cooper, ACAP Information Officer, 22 September 2021

Mike Double, as he writes “looking suitably cold down in Antarctica”

At the 12th Meeting of the ACAP Advisory Committee, held virtually due to the COVID-19 pandemic earlier this month, its Chair, Nathan Walker (Ministry for Primary Industries, New Zealand) stood down.  The meeting then elected Dr Michael Double in his place.

Mike Double is a Principal Research Scientist at the Australian Antarctic Division, based in Kingston, Tasmania where he leads the AAD’s Wildlife Ecology and Management Section (that conducts research on ACAP-listed species) and the Australian Marine Mammal Centre.  Mike obtained his PhD from the United Kingdom’s University of Leicester in 1995.  He then moved to Australia to take up a post-doctoral fellowship at the Australian National University in Canberra, followed by a move to the Australian Antarctic Division in 2007.  His research interests include the movement, distribution and population ecology of both marine mammals and seabirds.  His more than 90 scientific publications include several papers on the biology, taxonomy and conservation of ACAP-listed Shy Thalassarche cauta and White-capped T. steadi Albatrosses.

Mike writes to ACAP Latest News:

"It’s an honour to be elected as Chair of the Advisory Committee and I look forward to serving ACAP and its Parties to progress the conservation of albatrosses and petrels.  These iconic birds of wild oceans continue to face many threats and although ACAP and its Parties have many conservation successes to celebrate, populations continue to decline.  ACAP’s role remains as critical as ever and I hope I can facilitate further steps towards reducing human-induced impacts on ACAP-listed species.”

Prior to his appointment as AC Chair, Mike Double served as a member of the Agreement’s Taxonomy Working Group from 2005, a large part of that period as its Convenor.  He has also attended international meetings of the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) and the International Whaling Commission (IWC) as a member of Australia’s delegations.

At AC12 Sebastián Jiménez (Uruguay) was appointed Co-convenor and Dimas Gianuca (Brazil) Co-vice convenor of ACAP’s Seabird Bycatch Working Group, which had met virtually a week before AC12.  These appointments were occasioned by the resignation of the SBWG’s Co-convenor, Anton Wolfaardt, so that he may concentrate his efforts as Project Leader for the Mouse-Free Marion Project.

The Advisory Committee took the occasion to thank Nathan for his leadership and dedication to the work of the Advisory Committee and Anton for his leadership and contributions to the Seabird Bycatch Working Group over many years.

With thanks to Mike Double.

John Cooper, ACAP Information Officer, 21 September 2021

 
Trail camera image of a cat near two Pink-footed Shearwaters on Isla Mocha; from the publication

Ryan Carle (Oikonos Ecosystem Knowledge, Robinson Crusoe Island, Chile) and colleagues have published in the open access electronic journal PLoS ONE on deploying trail cameras to record the presence of mammals within breeding colonies of the globally Vulnerable Pink-footed Shearwater Ardenna creatopus.

The paper’s abstract in English and Spanish follows:

“Biodiversity conservation planning requires accurate, current information about species status and threats.  Although introduced mammals are the greatest threat to seabirds globally, data on introduced species is lacking for many seabird breeding islands.  To inform conservation planning, we used trail cameras to document the presence, relative abundance, and seasonal and diel attendance of introduced and native vertebrates within pink-footed shearwater (Ardenna creatopus) breeding colonies on Isla Mocha (five colonies, 2015–2020) and Isla Robinson Crusoe (Juan Fernández Archipelago), Chile (one colony, 2019–2020).  The most commonly detected species were pink-footed shearwaters and introduced rats (Rattus spp.) on Isla Mocha, and European rabbits (Oryctolagus cuniculus) and pink-footed shearwaters on Isla Robinson Crusoe.  Introduced mammals observed, in order of greatest catch-per-unit-effort, were rats, cats (Felis catus), dogs (Canis lupus familiaris), and European hares (Lepus europaeus) on Isla Mocha and European rabbits, cats, cattle (Bos taurus), rats, dogs, mice (Mus musculus), and southern coati (Nasua nasua) on Isla Robinson Crusoe.  Especially noteworthy results for pink-footed shearwater conservation were the presence of cats during all monitoring months in shearwater colonies on both islands, that catch-per-unit-effort of rabbits was greater than shearwaters on Isla Robinson Crusoe, and that rats were the most observed vertebrates after shearwaters on Isla Mocha.  Pink-footed shearwaters were regularly present on the islands from October through May.  Presence and relative catch-per-unit-effort of pink-footed shearwaters qualitatively matched the species’ known breeding phenology.  The regular presence and temporal overlap with shearwaters of cats, rats, rabbits, and cattle within shearwater colonies, coupled with the irregular presence of dogs, coati, hares, and mice, indicated a serious conservation threat for pink-footed shearwaters and other native insular fauna and flora.  Finally, our study provides a widely applicable model for analysis of multi-year trail camera data collected with unstandardized settings.”

A feral cat inspects a Pink-footed Shearwater burrow, photograph from Oikonos

Resumen en Español:

La planificación para la conservación de la biodiversidad requiere información precisa y actualizada sobre el estado de las especies y sus amenazas. Aunque los mamíferos introducidos son la mayor amenaza para las aves marinas a nivel mundial, faltan datos sobre especies introducidas presentes en muchas islas donde nidifican aves marinas. Para orientar la planificación de la conservación, utilizamos cámaras trampas que documentaron la presencia, abundancia relativa y visitación estacional y diaria de vertebrados introducidos y nativos dentro de las colonias reproductivas de fardela blanca (Ardenna creatopus) en Isla Mocha (cinco colonias, 2015-2020) e Isla Robinson Crusoe en el Archipiélago Juan Fernández (una colonia, 2019-2020), Chile. Las especies más comúnmente detectadas en Isla Mocha fueron la fardela blanca y ratas introducidas (Rattus spp.), y el conejo europeo (Oryctolagus cuniculus) y la fardela blanca en Isla Robinson Crusoe. Los mamíferos introducidos más detectados, en orden de mayor captura por unidad de esfuerzo, fueron ratas, gatos (Felis catus), perros (Canis lupus familiaris) y liebres europeas (Lepus europaeus) en Isla Mocha y conejos, gatos, ganado bovino (Bos taurus), ratas, perros, ratones (Mus musculus) y coatíes (Nasua nasua) en la Isla Robinson Crusoe. Los resultados más relevantes para la conservación de la fardela blanca mostraron la presencia de gatos durante todos los meses de monitoreo en las colonias reproductivas en ambas islas, mayor captura por unidad de esfuerzo de conejos que de fardelas en la Isla Robinson Crusoe, y la gran presencia de ratas en Isla Mocha siendo los vertebrados más registrados después de las fardelas. Las fardelas blancas estuvieron presentes regularmente en ambas islas desde octubre hasta mayo. La presencia y captura relativa por unidad de esfuerzo de fardela blanca coincide cualitativamente con la fenología reproductiva conocida para la especie. La presencia regular y la superposición temporal de fardelas con gatos, ratas, conejos y ganado bovino dentro de las colonias de fardela, junto con la presencia irregular de perros, coatís, liebres y ratones, indican una amenaza seria para la conservación de la fardela blanca y otras especies nativas. Finalmente, nuestro estudio proporciona un modelo ampliamente aplicable para el análisis de datos recopilados por varios años a través de cámaras trampas con configuraciones no estandarizadas.

Reference:

Carle, R.D., Fleishman, A.B., Varela, T., Manríquez Angulo, P., De Rodt, G., Hodum, P., Colodro, V., López, V. & Gutiérrez-Guzmán, H. 2021.  Introduced and native vertebrates in pink-footed shearwater (Ardenna creatopus) breeding colonies in Chile.  PLoS ONE  doi.org/10.1371/journal.pone.0254416.

John Cooper, ACAP Information Officer, 20 September 2021

Start of the season: a Laysan Albatross pair meets up

“From parents reuniting and mating, from egg-laying to chicks hatching, from fuzzy waddling to courageous fledging, the cycle has once again done a full spin on an axis of wind, squid and sheer perseverance.” - Hob Osterlund

Globally Near Threatened Laysan Albatrosses Phoebastria immutabilis breed close to the human habitants on the Hawaiian island of Kauai. Nests can be found in gardens, yards and on golf courses in the community of Princeville and along the north-east coast, as well as within a military facility and a wildlife refuge.  Each year Hob Osterlund, albatross photographer nonpareil and founder of the Kaua`i Albatross Network, tallies up the numbers of known nests for the whole island and reports on their success.  This year breeding success was 46.7%, following a hatching success of 68.8%, as she writes, accompanied by a selection of her superb photographs, on the Safina Center website:

“This year’s totals: 317 nests produced 218 chicks; of those, 148 chicks survived to fledge. Scientists measure results by “reproductive success” (RS) and express it in a percentage of how many nests resulted in how many fledges. This year the RS is about 47%, nearly identical to the average RS of the last seven years, and up from about 38% in 2020. Thankfully, wild pig and unleashed dog predation have decreased with better fencing, hunting and deterrents.  Sadly, feral cat predation is a bigger problem; this year we lost a total of 23 chicks in several colonies.”

A Laysan Albatross and its chick vocalize to each other

ACAP Latest News has previously reported on the harm cause by feral cats and dogs running loose among Kauai’s albatrosses.  With dogs now reported as less of a threat, cats remain an ongoing problem, although the intention to erect a new predator-proof fence at the Kilauea Point National Wildlife Refuge on Kauai that will deter feral cats should lead to an improved breeding success for that population.  For the 2020/21 season within the refuge hatching success was reported by the Friends of Kauaʻi Wildlife Refuges as 67.4% (87/129), similar to Hob’s percentage for the whole island (which includes the refuge figures).  Sixty-one of the 87 chicks fledged, giving an overall breeding success for the refuge of 47.3%, suggesting the value of having an improved fence that will keep out cats.

Not cat proof.  A Laysan Albatross chick rests by a fence on Kauai prior to fledging
Photographs by Hob Osterlund

With thanks to Thomas Daubert, Friends of Kauaʻi Wildlife Refuges and Hob Osterlund, Kaua'i Albatross Network.

John Cooper, ACAP Information Officer, 17 September 2021