Newell’s Shearwater, photograph by Eric VanderWerf

Andre Raine and colleagues (Archipelago Research and Conservation, Hawaii, USA) have published in the open-access journal Avian Conservation and Ecology on observations of interspecific competition between Endangered Hawaiian Petrels and Critically Endangered Newell’s and Wedge-tailed Shearwaters.

The paper’s abstract follows:

““Colony creation projects are a vital tool for the recovery of threatened and endangered seabird populations and have significant conservation value by creating colonies inside highly protected and more easily managed areas.  However, project sites need to be carefully chosen using a wide range of criteria to maximize success.  One of these criteria is the potential for interactions with species already breeding within the site, in particular the possibility of interspecific competition.  We considered three species of Procellariids in Hawaiʻi—two endangered Hawaiian endemics, the ʻuaʻu (Hawaiian Petrel, Pterodroma sandwichensis) and the ʻaʻo (Newell’s Shearwater, Puffinus newelli) and one native, the Wedge-tailed Shearwater (Ardenna pacifica)—to assess the prevalence of interspecific competition.  Colony monitoring was conducted at six management sites on the island of Kauaʻi, one on the coast and five in the mountains.  Cameras were deployed at breeding burrows and any interactions between species recorded.  Interspecific competition was recorded at all sites.  At the coastal site, Wedge-tailed Shearwaters consistently attacked breeding pairs of ʻaʻo and ultimately evicted 55.6% of established breeding pairs and 87.5% of prospectors.  At montane management sites, aggressive interactions were recorded between ʻuaʻu and ʻaʻo at all sites and increased over time in tandem with population increases.  Colony creation is an essential component of seabird conservation worldwide but, as this study shows, the presence of other breeding seabird species needs to be considered in the planning process if these projects are to succeed.  This is particularly true if Wedge-tailed Shearwaters are already present (or could recolonize the site) and/or if the site already has a high density of a breeding species that is of a similar size and utilizes the same breeding habitat and breeding strategy.”

An aggressive interaction between a Hawaiian Petrel and a Newell's Shearwater at the latter’s burrow

Reference:

Raine, A.F., Driskill, S., McFarlin, M., Brittingham, R., Rothe, J.A. & H. Raine, H. 2026.  Interspecific competition among procellariids: implications for seabird management and colony creation projects.  Avian Conservation and Ecology 21. doi.org/10.5751/ACE-02962-210101.

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 29 April 2026

Images of deceased shearwaters on beaches in southeastern Australia, from the publication

Jennifer Lavers (Adrift Lab, Underwood, Tasmania, Australia) and colleagues have published open access in the journal Conservation Biology, reporting that marine heat waves resulted in an estimated 629 000 seabird deaths, notably of two Australian shearwater species, in 2023–2024.

The paper’s abstract follows:

“Marine heat waves detrimentally affect a range of marine species, including seabirds, and are increasing in frequency and severity.  When thousands of dead seabirds wash up on beaches, the public becomes concerned.   However, the number of dead birds recorded on beaches is only a fraction of the total mortality; most birds perish at sea. As a result, estimates of total mortality are scarce, and this impedes the ability to determine how such mortality events affect populations.  Community science programs can greatly enhance the geographic or temporal scale of studies, which can be critical when mortalities or changes take place over large distances or many months.  Using three community science data repositories, we examined the number and composition of seabirds found dead on beaches in eastern Australia during the 2023–2024 marine heat wave.  Mortality estimation models developed for other sectors were refined using measures of searcher efficiency and carcass persistence for beach-washed birds. Total mortality of sable shearwaters (Ardenna carneipes) and short-tailed shearwaters (Ardenna tenuirostris) was >13,900 and >608,000, respectively.  The loss of these birds, in total more than 629,000 individuals, highlights the increasingly perilous marine environment in which many marine species now exist.”

Reference:

Lavers, J.J., Fulton, W., Stuckenbrock, S. & Bond, A L. 2026.  Estimating the total mortality of seabirds following a marine heat wave.  Conservation Biology doi.org/10.1111/cobi.70273.

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 28 April 2026

Streaked Shearwaters in a breeding colony

Helen Pružina (School of Biological and Environmental Sciences, University of Stirling, United Kingdom) and colleagues have published in the open-access journal Marine Ornithology on young Near Threatened Streaked Shearwaters Calonectris leucomelas socializing ashore during the breeding season.

The paper’s abstract follows:

“Many seabird species have a long breeding-deferral period, during which individuals mature and spend most of their time at sea, making them particularly difficult to study.  In some species, immatures are known to start visiting colonies before reaching adulthood, presumably to learn the behaviours required to secure a nest and mate for future breeding.  However, immature colony attendance remains undocumented in many species, particularly those that are difficult to observe, such as nocturnal, cavity-nesting species and species in which immatures are indistinguishable from adults.  Here, we studied the attendance patterns and behaviour of Streaked Shearwaters Calonectris leucomelas on Awashima Island, Japan, during the chick-rearing period.  We logged the number and duration of visits to the colony and assessed the potential influence of moonlight on these metrics.  We found a weak effect of moonlight on attendance but identified two types of nocturnal visits: one in which birds spent little time above ground and the other in which birds spent hours sitting on the surface.  During the latter, birds often gathered in groups and either rested or engaged in behaviours such as allopreening, fighting, calling, and digging burrows.  These longer visits sharply decreased in numbers well before the end of the chick-rearing period, and we suggest these visits are most likely undertaken by immatures, based on behaviours documented in other shearwater species.  The presence of immature Streaked Shearwaters at the colony during the breeding period has implications for the population ecology of the species and highlights the potential impact of predators and other at-colony risks on an additional age class of Streaked Shearwaters, beyond adults and chicks.”

Reference:

Pružina, H.M., Shoji, A., Shirai, M., Matsumoto, S., Yoda, K. & Fayet, A L. 2026.  Evidence for colony attendance by immature Streaked Shearwaters Calonectris leucomelas during the chick-rearing period.  Marine Ornithology 54: 79-86.

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 27 April 2026

 A breeding Black-browed Albatross on Kerguelen Island, photograph by Deborah Pardo

Bertille Mohring (School of Environmental Sciences, University of Liverpool, UK) and colleagues have published open access in the journal Ecology Letters on differing life-history strategies of Black-browed Albatrosses Thalassarche melanophris on Bird Island in the South Atlantic and Kerguelen Island in the southern Indian Ocean.

The paper’s abstract follows:

“Individuals face a trade-off between allocating resources to reproduction or self-maintenance, yet the drivers of the existence and strength of such trade-off have been hard to determine.  Environmental conditions are thought to play a crucial role, as long-lived species are predicted to favour more precautionary life-history strategies in variable environments.  However, empirical evidence remains limited.  Using long-term monitoring of two black-browed albatross Thalassarche melanophris populations, we investigated variation in life-history strategies under contrasting environmental conditions, through reproductive senescence.  In more variable environments, individuals displayed generally slower life histories (i.e., slow, late-onset senescence) and greater among-individual variation in life-history strategies.  Interestingly, earlier and faster reproductive senescence correlated with higher lifetime reproductive success regardless of environmental variability, suggesting that either faster life histories incur higher fitness or successful reproduction accelerates reproductive senescence.  These findings reveal how environmental variability shapes life-history strategies, highlighting potential responses to increasing environmental variability in a changing world.”

With thanks to Karine Delord and Richard Phillips.

Reference:

Mohring, B., Potts, J.R., Wilson, A.J., Réale, D., Phillips, R.A., Weimerskirch, H., Barbraud, C., Bennison, D., Delord, K., Wood, A.G., Peroteau, S., Rouby, E., Ventura, F. & Patrick, S.C. 2026.  Environmental variability shapes life-history trade-offs within and between populations of a long-lived seabird.  Ecology Letters 29(4).  doi.org/10.1111/ele.70384.

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 24 April 2026