Grey Petrel, photograph by Peter Ryan

Kalinka Rexer-Huber and Graham Parker (Parker Conservation, Dunedin, New Zealand) have reported this month to the Conservation Service Programme of New Zealand’s Department of Conservation on how best to estimate Grey Petrel Procellaria cinerea numbers on Antipodes Island.

The draft report’s summary follows

“Antipodes Island is thought to have by far the largest population globally of grey petrels Procellaria cinerea, but the trend in population size over time remains unknown. This work focuses on planning an updated estimate of population size and trend. We collate and assess resources from previous work, using these to develop recommendations for field work that will yield a robust population estimate.

Our focus here is the methods and findings of grey petrel studies on Antipodes in the early and late 2000s: the feasibility study in 2001 (Bell 2002) and population research in 2009–10 (Thompson 2019). A valuable record of observations underpinned those studies, so key observations on grey petrel behaviour and occurrence over trips since 1969 were extracted from notebooks by Bell and Burgin (Appendix A).

We first collated resources, then compared and contrasted methods and findings from previous work (section Assess existing information). Requirements for a robust, repeatable population size estimate and best-practise approaches are discussed in Design a robust population estimate. Taken together, previous work and requirements inform a range of options for population size estimation, with key pros and cons noted for each field strategy (Ranked methodologies).

Balancing effort, flexibility and precision of the population size estimate, the recommended field strategy is spatial coverage distance sampling. This approach uses distance sampling following a simple-random design that maximises spatial coverage. Several other good options suggest variations but with key things in common: timing (occupancy sampling should occur in second half April), accounting for habitat lost to landslips, and using true surface areas of grey petrel habitat in calculations. With broad sampling across the grey petrel range, an accurate, robust, repeatable population size estimate can be produced.”

Reference:

Rexer-Huber, K. & Parker, G. 2020.   Antipodes Island grey petrels: assess and develop population estimate methodology. DRAFT Final report to Department of Conservation, Conservation Services Programme for project POP2020-04: Grey petrel population estimate methodology, Antipodes Island.  Dunedin: Parker Conservation.  35 pp.

John Cooper, ACAP Information Officer, 23 December 2020

A Hawaiian Petrel or Ua‘u, photograph from the Pacific Rim Conservation Facebook page

Hawaiian NPO Pacific Rim Conservation, with field support from the Kaua'i Endangered Seabird Recovery Project, has worked for six years hand rearing chicks of translocated globally Endangered Hawaiian Petrels (‘Ua‘u) Pterodroma sandwichensis and globally Critically Endangered Newell’s Shearwaters (‘A‘o) Puffinus newelli from the inland mountains on the Hawaiian island of Kauai  The translocated chicks were placed in artificial burrows within a specially built predator-proof fence at the coastal Nihoku Ecosystem Restoration Project site within the Kilauea Point National Wildlife Refuge.

“First Flight: Hawaiian Petrels Journey to Safety” - American Bird Conservancy

''After six years of translocating both Hawaiian Petrels and Newell’s Shearwaters to [the] Kilauea Point National Wildlife Refuge, we are thrilled to see the last of our chicks safely take to the skies to begin their lives at sea”.  All 87 Newell’s Shearwaters which were translocated successfully fledged, and 106 of the hand-reared 110 Hawaiian Petrels made it out to sea, with the last two petrels of the 2020 cohort departing this month.  So far five Hawaiian Petrels have returned to the Nihoku site as adults – a good harbinger for the establishment of a new breeding colony for one of the two threatened tubenose species that are both endemic to the Hawaiian islands.

Read earlier posts on the Nihoku Ecosystem Restoration Project in ACAP Latest News here.

John Cooper, ACAP Information Officer, 22 December 2020

Graphical Abstract - from the publication

Kosuke Tanaka (Laboratory of Toxicology, Department of Environmental Graduate School of Veterinary Medicine, Hokkaido University, Japan) and colleagues have published in the journal Current Biology on feeding plastics to chicks of streaked shearwater Calonectris leucomelas.

The paper’s summary follows:

“Plastic debris is ubiquitous and increasing in the marine environment. A wide range of marine organisms ingest plastic, and its impacts are of growing concern. Seabirds are particularly susceptible to plastic pollution because of high rates of ingestion. Because marine plastics contain an array of hazardous compounds, the chemical impacts of ingestion are concerning. Several studies on wild seabirds suggested accumulation of plastic-derived chemicals in seabird tissues. However, to date, the evidence has all been indirect, and it is unclear whether plastic debris is the source of these pollutants.  To obtain direct evidence for the transfer and accumulation of plastic additives in the tissues of seabirds, we conducted an in vivo plastic feeding experiment. Environmentally relevant exposure of plastics compounded with one flame retardant and four ultraviolet stabilizers to streaked shearwater (Calonectris leucomelas) chicks in semi-field conditions resulted in the accumulation of the additives in liver and adipose fat of 91 to 120,000 times the rate from the natural diet. Additional monitoring of six seabird species detected these chemical additives only in those species with high plastic ingestion rates, suggesting that plastic debris can be a major pathway of chemical pollutants into seabirds. These findings provide direct evidence of seabird exposure to plastic additives and emphasize the role of marine debris ingestion as a source of chemical pollution in marine organisms.”

Reference:

Tanaka, K., Watanuki, Y., Takada, H., Ishizuka, M., Yamashita, R., Kazama, M., Hiki, N, Kashiwada, F., Mizukawa, K., Mizukawa, H., Hyrenbach, D., Hester, M., Ikenaka, Y. & Nakayama, S.M.M.  2020.  In vivo accumulation of plastic-derived chemicals into seabird tissues.  Current Biology doi.org/10.1016/j.cub.2019.12.037.

John Cooper, ACAP Information Officer, 21 December 2020

Pink-footed Shearwater at sea, photograph by Kirk Zufelt

Writing in Spanish, Rodrigo Silva (Programa Aves Marinas, Red de Observadores de Aves y Vida Silvestre de Chile) and colleagues have reviewed the impacts of light pollution on 17 species of Chilean seabirds (including the ACAP-listed Pink-footed Shearwater or Fardela blanca Ardenna creatopus) in the journal Ornitología Neotropical.

The paper’s abstract follows in both English and Spanish:

“Light pollution affects seabirds through the attraction to light sources and its fallout all over the world, being petrels and shearwaters the most affected species. Light pollution is increasing globally and its effects on seabirds will likely increase during the next years. A global assessment of this issue has been made, but there is no detailed information about South America; thus, the aim of this article is to assess the situation in Chile, in order to suggest technical measures to be considered into the national light pollution policy, which could promote the addressing of the issue in South America. To do so, a diagnosis on marine bird species was made through direct consultation with experts, a systematic review, and research in free access databases. We found 17 seabirds species affected by fallout in Chile, including six species not previously recognized in the literature. The impact is mainly distributed in islands and coastal localities, but also inland, as far as 100 km from the shore. Most of the management of this phenomenon done in Chile is restricted to the rescue and release of affected birds, although there is no evidence of the long-term success of this approach. Measures, such as turning off lights or light replacement are rare, implemented at a small scale, and have unknown results. An update of the light pollution policy is required in Chile, which should consider the protection of biodiversity as a goal, the national geographic scope beyond areas of astronomical interest, and including new lighting technologies such as LED lights. Finally, the development of stronger regulations for human activities, like lighting near sensible points, including seabirds’ breeding grounds, is especially important.”

“Resumen  La contaminación lumínica afecta a las aves marinas por la atracción hacia fuentes de luz y su posterior caída (fallout) en todo el mundo, siendo los petreles y fardelas las especies más afectadas. La contaminación lumínica está aumentando globalmente y probablemen-te sus efectos sobre estas aves se incrementen en los próximos años. Pese a que existe una evaluación global de esta materia, no existe in-formación detallada para Sudamérica; por esto, el objetivo de este artículo es elaborar un diagnóstico de la situación en Chile, a fin de sugerir un enfoque técnico y político para el país y promover la discusión y acciones al respecto para la región sudamericana. Para ello, se elaboró un diagnóstico de las especies de aves marinas y territorios afectados a través de la consulta directa a investigadores, la revisión sistemática y búsqueda en bases de datos de acceso libre. En Chile, 17 especies de aves marinas son afectadas por la contaminación lumínica, incluyendo seis especies no identificadas previamente en la literatura. El impacto se distribuye principalmente en islas y localidades costeras, con algu-nos casos de localidades a más de 100 km al interior desde la costa. La mayor parte del manejo de este fenómeno en Chile consiste en el rescate y liberación de aves, aunque no hay evidencia del éxito de este enfoque a largo plazo. Medidas como el apagado o recambio de luces son escasas y sólo se han adoptado a pequeña escala y con resultados desconocidos a la fecha. Por ello, una actualización de la política de contaminación lumínica es requerida en Chile y debe considerar la biodiversidad como objeto de protección, el alcance geográfico nacional más allá de las áreas de interés astronómico y debe incluir nuevas tecnologías de iluminación, como luces LED. Finalmente, será de especial importancia la generación de regulaciones más estrictas sobre actividades humanas, incluyendo la iluminación en las cercanías a puntos sensibles, como colonias reproductivas de aves marinas.”

Reference:

Silva, R., Medrano, F., Tejeda, I., Terán, D., Peredo, R., Barros, R., Colodro, V., González, P., González, V., Guerra-Correa, C., Hodum, P., Keitt, B., Luna-Jorquera, G., Malinarich, V., Mallea, G., Manríquez, P., Nevins, H., Olmedo, B., Páez-Godoy, J., de Rodt, G.H., Rojas, F., Sanhueza, P., Suazo, C.G., Toro, F. & Toro-Barros, B. 2020.  Evaluación del impacto de la contaminación lumínica sobre las aves marinas en Chile: diagnóstico y propuestas  [Assessing light pollution impacts on seabirds in Chile: diagnosis and proposals].  Ornitología Neotropical 31: 13-24.

John Cooper, ACAP Information Officer, 18 December 2020