Light-morph Wedge-tailed Shearwater at sea, photograph by Brian Sullivan

Penny Beaver (Institute for Marine and Antarctic Studies, University of Tasmania, Battery Point, Tasmania, Australia) and colleagues have published in the open access journal Ecology and Evolution on the at-sea distribution of two populations of Australian Wedge-tailed Shearwaters Ardenna pacifica.

The paper’s abstract follows:

“Wedge-tailed shearwaters (Ardenna pacifica) are widely distributed across tropical and subtropical oceans, with their breeding range recently extending south.  For populations at their southernmost breeding range, habitat use, spatial segregation, and trophic niche dynamics remain poorly understood.  Here, we investigated the habitat use, spatial segregation, and trophic niche differentiation in two disjunct populations of wedge-tailed shearwaters in eastern Australia, between 2015 and 2019.  Both populations exhibited consistent spatial segregation across all years of the study.  Individuals from the temperate population consistently foraged in waters off southeastern Australia.  Prior to winter migration to the western Pacific Ocean (Philippine Sea), most individuals undertook a pre-staging detour towards the subtropical frontal zone.  In contrast, subtropical conspecifics exploited waters further east and north, with a small proportion undertaking a pre-staging detour only in the first year.  Stable isotope analysis of chick feathers (δ¹⁵N and δ¹³C) revealed trophic and habitat segregation between colonies.  With the subtropical population consistently occupying a smaller trophic niche area and exhibiting lower interannual variation across all years.  Both populations exhibited a high degree of interannual variability in foraging strategies and trophic niches, indicating a capacity for behavioural adaptivity in response to prey availability and oceanic conditions.  This behavoural [sic] flexibility may facilitate future range expansion into more southern temperate habitats, which is important given projected climate-driven changes to ocean dynamics in southeastern Australia.”

Reference:

Beaver, P.E., Carlile, N., Sumner, M.D. & Lea, M. 2026.  Spatial segregation and trophic niche divergence in two disjunct populations of Wedge‐tailed Shearwater Ardenna pacifica in eastern Australia.  Ecology and Evolution 16(3) doi.org/10.1002/ece3.73158.

With apologies to Bob Dylan.

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses, 06 May 2026

A Townsend’s Shearwater fledgling in the hand, photograph by Juan Martinez

Fernando Solís-Carlos (Grupo de Ecología y Conservación de Islas, Ensenada, Baja California, Mexico) and many colleagues have published open access in the journal Oryx on the conservation of the Critically Endangered Townsend’s Shearwater Puffinus auricularis.

The paper’s abstract follows:

“Mexico ranks third globally in seabird diversity and second in the number of endemic species that breed within its territory, yet 16% of seabird species in the country are categorized as threatened on the IUCN Red List, including the Critically Endangered Townsend’s shearwater Puffinus auricularis.  Nearly 20 years ago, the breeding population of Townsend’s shearwater, which is endemic to the Revillagigedo Archipelago of Mexico, was inferred to comprise < 100 breeding pairs.  Since then, conservation initiatives have been implemented in the archipelago.  We assessed the current status of Townsend’s shearwater by mapping the distribution of breeding colonies, estimating breeding population size, evaluating reproductive success, describing ongoing threats and modelling population trends under three conservation scenarios.  During 2016–2024, we conducted field surveys on the islands of Socorro and Clarión using acoustic monitoring techniques in historical nesting areas.  We estimated that the breeding population on Socorro comprises < 200 pairs and documented the return of a small breeding population to Clarión after a 30-year absence.  However, reproductive failure persists because of the effects of native predators such as land crabs, snakes and ravens.  The population has exhibited a slow decline driven by interactions between native and invasive species.  Without ongoing restoration efforts and management actions, including the removal of feral cats, the population could face extinction.”

Reference:

Solís-Carlos, F., Ortiz-Alcaraz, A., Aguirre-Muñoz, A., Bedolla-Guzmán, Y., Fabila-Blanco, A., Aztorga-Ornelas, A., Félix-Lizárraga, M., Góngora-Salinas, J., Castillo-Huerta, N., Íñigo-Elías, E., Rojas-Mayoral, B., Macías-López, I., Piña-Vera, E. & Méndez-Sánchez, F.. 2026.  Update on the conservation status of Townsend’s shearwater Puffinus auricularis: breeding colonies, reproductive success and population trend.  Oryx doi:10.1017/S0030605325102123.

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses, 05 May 2026

An Atlantic Yellow-nosed Albatross flies past Gough Island.  Soft pastels on Pastelmat by Deepti Jain of Artists & Biologists Unite for Nature (ABUN) for World Albatross Day 19 June 2026 and its theme of “Habitat Restoration”, after photographs by Chris Jones and Laurie Smaglick Johnson

In an important review, Ioannis Kalaitzakis (Dipartimento di Scienze e Politiche Ambientali, Università degli Studi di Milano, Italy) and many colleagues have published in the open access journal Conservation Science and Practice identifying invasive predators (cats and rodents) as the largest threats faced on land by Atlantic pelagic seabirds.  Gough Island in the South Atlantic, which supports five ACAP-listed albatrosses and petrels, is given a high priority for action due to its seabird-killing House Mice Mus musculus.  The mice are still present after an unsuccessful eradication effort in 2021.

However, the paper contains some misleading and incorrect errors in relation to the Tristan-Gough group of islands (that it refers to as “Tristan & Gough”).  Most significantly, the publication lists feral cats as a threat requiring removal from the main island of Tristan da Cunha, yet in fact they have not occurred there for half a century  The feral population is believed to have died out around the time the whole domestic cat population of 54 animals was shot by the island’s medical doctor, who reported them as a human health risk from toxoplasmosis in February 1974 (Richardson 1984).

I also take issue with the statement “Furthermore, although mice are currently the most impactful alien predator across [my emphasis] this archipelago …”.  Mice do not occur on Nightingale or Inaccessible Islands (and never have), there is no evidence they are a problem for birds on Tristan (likely suppressed by the island’s introduced Black Rats Rattus rattus) so it is only on Gough that they are an “impactful predator”.

The publication is correct in stating that the Vulnerable Spectacled Petrel Procellaria conspicillata is endemic to the island group, but including it in the same sentence with the equally endemic Critically Endangered Tristan Albatross Diomedea dabbenena , Endangered Atlantic Yellow-nosed Albatross Thalassarche chlororhynchos and Endangered Atlantic Petrel Pterodroma incerta of Gough Island, where they are all at risk to mice (as are the other seabird species on the island), is a little misleading.  The Spectacled Petrel breeds only on Inaccessible Island, which has never supported introduced populations of cats or rodents.

The Tristan-Gough group is made up of four islands and several islets on which seabirds breed.  These islands fall under differing conservation management regimes, and their seabird (and landbird) species compilations vary.  For example, the main island is the only one with a permanent human population, Inaccessible and Gough are nature reserves with a combined management plan, they together form a World Heritage Site, whereas Nightingale, and its two islets on which seabirds breed, has no formal conservation status.  As I have shown, the alien mammal populations vary, with two islands being free of them.  However, the group’s islands and islets do fall under a single management authority, the Tristan da Cunha Conservation Department in terms of the 2006 Tristan da Cunha Conservation Ordinance.

The paper’s abstract follows:

“Seabirds are exposed to numerous threats throughout their life-cycles, including land-based threats during their breeding season such as invasive species, diseases, or light pollution.  Here we assess the timing, scope, and severity of land-based threats to populations of highly mobile petrels, albatrosses, storm-petrels, and alcids in the Atlantic Ocean, to guide priorities for their conservation across their mostly island-breeding areas.  By combining our own field expertise of these species with a literature review, we built a dataset characterizing 18 threats for 49 species across 38 Large Marine Ecosystems.  We analyze this dataset by highlighting the most impactful threats and the most impacted regions.  Addressing invasive alien species on Tristan da Cunha & Gough and on the islands of the Canary Current are the interventions with the greatest potential to stimulate seabird population recovery across the Atlantic Ocean.  Our results highlight priorities for targeted management actions that can support seabird conservation.”

References:

Kalaitzakis, I., Rodrigues, A.S.L., Dias, M.P., Davies, T.E., Baran, M.A., Bhola, N., Boulinier, T., Bried, J., Campioni, L., Ceia, F.R., De Pascalis, F., Dehnhard, N., Fagundes, A.I., Gilg, O., González-Solís, J., Grémillet, D., Hernández-Montero, M., Krüger, L., Kuepfer, A. … Rouyer, M.-M. 2026.  Assessment of land-based threats to Atlantic pelagic seabirds.  Conservation Science and Practice 8(3). doi.org/10.1111/csp2.70249.

Richardson, M.E. 1984.  Aspects of the ornithology of the Tristan da Cunha Group and Gough Island.  Marine Ornithology 12: 123-201.

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses, 04 May 2026

“A staggering 168 dead birds”, collected together to count and photograph by Archipelago Research and Conservation

“The 'ua'u kani (Wedge-tailed Shearwater Ardenna pacifica) breeding season has barely started and already we have a mass slaughter event.  After receiving a report from a member of the public about dead shearwaters near Shipwreck Beach we visited the colony and found a staggering 168 dead birds.  These were all adult birds returning to their burrows to start breeding, and all were killed by cats (as clearly evidenced by the nature of their injuries and the disposition of the bodies).  This is a sadly all too familiar scene here on Kaua'i (and across the Hawaiian Islands).  Cats need to be indoors, where they are safe and not annihilating our native wildlife.  We have reported this massacre to the authorities.”

News from the Facebook page of Archipelago Rim Conservation.  View a 2m 20s video of the episode that shows rhe characteristic signs of a cat kill.

Trail camera photograph of a cat carrying a Wedge-tailed Shearwater on Kauai, from Hob Osterlund

As well as cats, feral pigs and free-roaming dogs have killed Wedge-tailed Shearwaters on Kauai.  Pigs have also been recorded attacking and eating Laysan Albatrosses Phoebetria immutabilis eggs on the island (read previous reports in ACAP Latest News). Also here on multiple incidents of dogs attacking and killing Laysan Albatross chicks and adults on Kauai.. 

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 01 May 2026, updated 02 May 2026