Short-tailed Albatross pair by ABUN artist Lucimara Wesolowicz‎, after a photograph by Cynthia Vanderlip

Eric Guiry (School of Archaeology and Ancient History, University of Leicester, UK) and colleagues have published open access in the journal Communications Biology on using archaeological information to learn about the past foraging fidelity of Short-tailed Albatrosses Phoebastria albatrus over thousands of years.

The paper’s abstract follows:

“Theory and field studies suggest that long-term individual foraging site fidelity (IFSF) may be an important adaptation to competition from increasing population. However, the driving mechanisms and extent of long-term IFSF in wild populations of long-lived, migratory animals has been logistically difficult to study, with only a few confirmed instances. Temporal isotopic datasets can reveal long-term patterns in geographical foraging behaviour. We investigate the isotopic compositions of endangered short-tailed albatross (Phoebastria albatrus) over four millennia leading up to their near-extinction. Although not exhibited by short-tailed albatross today, we show past sub-populations displayed a high-degree of long-term IFSF, focusing on the same locations for hundreds of generations. This is the first large-scale evidence for the deep antiquity of long-term IFSF and suggests that it’s density-driven. Globally, as populations of species like short-tailed albatross continue to recover from overexploitation, potential for resurgence of geographic specialization may increase exposure to localized hazards, requiring closer conservation monitoring.”

Read a popular article on the study here.

With thanks to Barry Baker and Ken Morgan.

Reference:

Guiry, E.J., James, M., Cheung, C. & Royle, T.C.A. 2022.  Four millennia of long-term individual foraging site fidelity in a highly migratory marine predator.  Communications Biology 5: 368..

John Cooper, ACAP Information Officer, 18 April 2022

Neotype of Phoebastria albatrus, dorsal view; from the publication

Takeshi Yamasaki (Yamashina Institute for Ornithology, Japan) and colleagues have published open access in the journal Zootaxa on designating a neotype for the Short-tailed Albatross Phoebastria albatrus. The bird is thought to have been from the population breeding on the Senkaku Islands.

The paper’s abstract follows:

“The Short-tailed Albatross (Pallas, 1769) is a threatened seabird widely distributed in the northern Pacific Ocean with its largest breeding sites on the Senkaku Islands and Torishima Island, Japan, which are separated by over 1700 km.  A recent taxonomic revision based on morphological, behavioral, and DNA sequence evidence has revealed that this species consists of two cryptic species: a smaller species which breeds mainly in the Senkaku Islands, and a larger species which breeds mainly on Torishima Island.  However, it has remained unclear to which of these species the scientific name Phoebastria albatrus applies, because the type specimens are lost. Here a neotype is designated to resolve this taxonomic issue.  From now on, the scientific name Phoebastria albatrus should be applied only to the smaller species breeding on the Senkaku Islands. The name of the larger species is more problematic, as the types of each synonym of P. albatrus must be traced, found, and examined.”

Read of three relevant publications featured in ACAP Latest News on Senkaku Short-tailed Albatrosses here, here and here.

Reference:

Yamasaki, T., Eda, M., Schodde, R. & Loskot, V. 2022.  Neotype designation of the Short-tailed Albatross Phoebastria albatrus (Pallas, 1769) (Aves: Procellariiformes: Diomedeidae).  Zootaxa 5124 (1): 081-087.

John Cooper, ACAP Information Officer, 15 April 2022

Pink-footed Shearwater by Pilan; after a photograph by Peter Hodum

Note:  The illustrated Species Summaries have been written to help inform the general public, including school learners, of the biology and conservation needs of the 31 ACAP-listed species.  They serve to complement the more detailed and referenced ACAP Species Assessments.  To date, summaries for the 22 species of albatrosses have been produced in in all three ACAP official languages, English, French and Spanish.

Texts have also been prepared for the nine ACAP-listed petrels and shearwaters in English, but as yet have not been translated into French and Spanish.  As an interim service, the illustrated English texts have been posted to ACAP Latest News, completing the series with the Pink-footed Shearwater Ardenna creatopus.

Pink-footed Shearwater at sea; photograph by Peter Hodum

The Pink-footed Shearwater is one of two shearwaters listed within the Albatross and Petrel Agreement (ACAP).  As for most members of the petrel family Procellariidae it breeds in burrows.  The bird is greyish brown with a white breast and belly and mainly white underwings.  The feet and legs are a distinctive pale pink, the bill yellowish with a dark tip.

The Pink-footed Shearwater has been confirmed to breed on only three islands off the coast of Chile: Islas Robinson Crusoe (52 km²) and Santa Clara (2.2 km²) in the Juan Fernández Archipelago and Isla Mocha (50 km²), farther north.  There are around roughly 28 000 - 30 000 breeding pairs in total, implying as many as 100 000 individuals when juveniles and non-breeding birds are included.  Isla Mocha supports over two thirds of the species’ breeding population.  Overall, the shearwater may have a stable population with trends on the three islands differing between them.

The species breeds colonially, laying single eggs in burrows during the austral summer on slopes in both forested and deforested grassy areas.  It is a trans-equatorial migrant, some satellite-tracked individuals have been recorded travelling outside the breeding season as far north as the Pacific waters of British Columbia, Canada and the Gulf of Alaska, staying in the main close to coastlines over the continental shelf.  Diet is dominated by small pelagic shoaling fish (sardines and anchovies) along with squid and crustaceans caught by surface seizing and diving.

The shearwater faces threats both on land and on sea.  On its breeding islands deforestation and ensuing erosion have reduced breeding site quality and introduced mammals have either reduced vegetation cover and trampling leading to burrow collapse and erosion on steep slopes (domestic cattle, goats, European Rabbits) or preyed upon birds (feral cats, domestic dogs, Coatimundis and possibly rats).  An illegal take of chicks for human consumption continues on Isla Mocha – which can include destroying burrows.  At sea it is at risk from bycatch, including by artisanal net and longline fisheries off the coast of Ecuador and Peru and a domestic trawl fishery off Chile.  Conservation efforts include erecting an introduced mammal-proof fence around a breeding site on Isla Robinson Crusoe and educating the islands’ inhabitants.  Rabbits have been eradicated on Isla Santa Clara leading to an increase in shearwater breeding numbers.  The Juan Fernández Archipelago is both a national park and a UNESCO Biosphere Reserve.  The breeding site on Isla Mocha falls within a national reserve, patrolled to deter poaching of chicks.  The 93-km² Juan Fernández Archipelago National Park was placed on Chile’s Tentative List for nomination as a World Heritage natural site in 1994.The Pink-footed Shearwater is listed both within ACAP since 2015 and in the Convention on Migratory Species on Appendix I.  Both national and international management plans exist for the species, which has been categorized with a global status of Vulnerable due to its small breeding range on only three islands and the threats described above.

Sources:

ACAP 2013.  Pink-footed Shearwater Ardenna creatopus.  AC7 Doc 24 Rev 1.

BirdLife International 2021.  Species factsheet: Ardenna creatopus.

John Cooper, ACAP Information Officer, 14 April 2022

 
Southern Giant Petrel and chick on a South Atlantic island; artwork by Leigh Wolfaardt

 Ulises Balza (Laboratorio de Ecología y Conservación de Vida Silvestre, Ushuaia, Argentina) and colleagues have published in the journal Polar Biology on censuses of breeding seabirds, including Southern Giant Petrels Macronectes giganteus, on Isla Observatorio in the Isla de los Estados (Staten Island) group: 387 pairs were counted in 2016.

The paper’s abstract follows:

“Continental islands are often sites of low diversity and endemism, as well as important areas for the protection of bird populations, especially seabirds. On Isla Observatorio and the Año Nuevo Islands, in the Southwestern Atlantic, the latest assessment of avifauna dates from more than 20 years ago. In this study, we use a combination of methods to update the status of the main seabird colonies and the most abundant avian terrestrial predator at Observatorio and Goffré Islands during the breeding season. In only 4.5 km², the islands would harbour ~ 90,000 breeding seabirds. Seabird colonies occupied different areas of the islands and varied in their population status, with Imperial Shags (Leucocarbo atriceps) showing an increase and a decrease according to the last surveys. Magellanic Penguin (Spheniscus magellanicus) population estimations also suggest a decrease but the last survey was based on total, and not on occupied nest sites. We recorded and assessed one new breeding species: The globally near-threatened Striated Caracara (Phalcoboenus australis), which has an important breeding population of around 15 territorial pairs at Observatorio Island. These islands appear to be an important regional bird site and future studies would determine their trends and threats, especially those related with invasive species.”

With thanks to Ulises Balza and Maro Favero.

Reference

Balza, U., Liljesthröm, M., Pimper, L., Franco-Navarro, I., Cañas-Barrovecchio, S., Zunino, F., Domato, I., Acardi, S., Iturraspe, R., Cano, J. & Raya-Rey, A. 2022.  Status of breeding birds at Observatorio and Goffré Islands, Argentina.  Polar Biology 45: 667-673.

John Cooper, ACAP Information Officer, 13 April 2022