Avian Predator Control Led to Increased Breeding Success of Common Murre Uria aalge on Teuri Island, Hokkaido

Highly pathogenic avian influenza clade 2.3.4.4b H5Nx viruses (HPAIVs) have caused significant mortality in wild birds. We investigated active avian influenza virus (AIV) infections and assessed seroprevalence based on general nucleoprotein-specific and H5-specific antibodies, in seabirds in Atlantic Canada during 2022-2023. Results were compared to seroprevalence data from 2011-2016 to evaluate changes in infection rates following the incursion of HPAIV. We sampled 1073 wild live birds belonging to 14 species. Active H5Nx infections were detected only in 2022, with the highest prevalence in Common Murres (64%), followed by Black-legged Kittiwakes (13%). Differences in seroprevalence were observed between years and species, with both Common Murres and Atlantic Puffins exhibiting higher rates after HPAIV incursion, particularly for anti-H5-specific antibodies. Seroprevalence also differed between locations, and age-related differences in exposure were observed with juvenile birds having much lower seroprevalence than adult birds, particularly among gulls. Despite no active infections being detected in 2023, high seroprevalence across species suggests persisting immunity and/or recent virus circulation. These findings underscore the importance of serological monitoring in tracking AIV dynamics, as antibody detection provides critical insights into past HPAIV exposure even when active infection rates are low.

Impacts to birds from marine oil spills in California, 1995-2019.

Two tufted puffins (Fratercula cirrhata) in a zoological collection of 10 birds presented with signs of weakness, ataxia, and decreased appetite. Diagnostic test results were supportive of zinc toxicosis. The remaining birds in the enclosure (four other tufted puffins, three common murres [Uria aalge], and one rhinoceros auklet [Cerorhinca monocerata]) were assessed, with plasma zinc levels ranging from 2.7 to 5.0 parts per million (ppm; 41.3-76.5 µmol/L). Possible environmental sources of zinc were investigated, including food, medications, seawater, plants, substrates, and habitat lining. Extremely high levels of zinc were found in the habitat sediment and lining (611,365 ppm at one site). A zinc coating had been applied to the habitat decades previously to reduce corrosion; the coating had eroded and contaminated grit was being ingested. All birds received chelation therapy with dimercaptosuccinic acid. A dosage of 50 mg/kg PO q24h appeared most effective and resolved all clinical signs. Long-term pulsatile use (months to years) was not associated with any complications. The birds were moved out of the habitat, the accessible lining was removed, the habitat was resealed, and any remaining sediment was flushed and removed prior to returning the birds. Morbidity and mortality in the group have decreased following this intervention. This case series highlights the importance of including veterinary professionals in the design and renovation plans for zoological enclosures.

Paralytic shellfish toxins and seabirds: evaluating sublethal effects, behavioral responses, and ecological implications of saxitoxin ingestion by common murres (Uria aalge).

The article presents the results of 2015-2020's colonial seabird surveys on Bering Island and analyzes the changes in their numbers and distribution over the past 30 years. The number of colonies on the island has not changed. There are 13 species nesting on the island and 4 species presumably nesting. Their total number exceeds 238,000 pairs. Most colonies are located in the southern part of the island, which includes five basic species: the Northern Fulmar Fulmarus glacialis, the Blacklegged Kittiwake Rissa tridactyla, the Red-legged Kittiwake Rissa brevirostris, and two guillemot species (Uria aalge and Uria lomvia). The most numerous is the Thick-billed Guillemot. The populations of the Red-legged Kittiwake, the Common Guillemot, and the Horned Puffin Fratercula corniculata have increased. The numbers of both cormorant species (Phalacrocorax pelagicus and Phalacrocorax urile) and of the Black-legged Kittiwake have decreased. For the rest of the species, no significant changes were exposed.

The 2014−2016 Pacific marine heatwave (PMH) was an intense and prolonged environmental disturbance that significantly disrupted the marine food web, leading to widespread ecological impacts. The PMH contributed to major shifts in species distributions, mass mortalities, and reproductive failures among upper-trophic level species, including a massive die-off of common murres (Uria aalge) in the Gulf of Alaska (GOA). To assess the impact of the PMH on the winter marine bird community in Prince William Sound (PWS), a large embayment in the northern GOA, we analyzed changes in winter marine bird abundance and species composition in a series of bays before and after the PMH. The overall density of winter marine birds decreased and species composition significantly changed in PWS following the PMH. Specifically, common murres, cormorants, and loons decreased from pre-PMH survey densities, while marbled murrelet (Brachyramphus marmoratus) densities increased. The post-PMH increase in marbled murrelets, likely due to immigration, coincided with the rapid growth and spatial expansion in the PWS Pacific herring (Clupea pallasii) young-of-the-year population and with a smaller, 8-month marine heatwave across the northern GOA. We suggest the mass mortality and lack of recovery by the common murre population provided a competitive release enabling murrelets to exploit a growing forage fish population, and that murrelets may be more effective at shifting to warmer-water zooplankton during marine heatwave events. These results highlight the persistent upper-trophic level changes associated with the PMH and provide important insights into the ecological consequences of environmental disturbances. This is increasingly relevant given the predicted increase in frequency and intensity of marine heatwaves.

The Faroe Shelf, located on the North Atlantic’s Iceland-Scotland ridge, has historically hosted a rich ecosystem with large seabird populations. However, substantial declines in their population sizes have been observed over the past half century. This study introduces and documents comprehensive decades-long data series from 1972-present on offspring production and adult attendance of four seabird species, the common guillemot, Atlantic puffin, black-legged kittiwake, and Arctic tern, breeding in major colonies in the Faroe Islands. Results show that the highly variable productivity of these seabirds is characterized by marked and synchronized peaks at 5- to 10-years intervals, and these peaks closely mirror indices of primary production and availability of pelagic juvenile fish on the Faroe shelf. These ecological signals are examined in the context of oceanographic changes in the subpolar North Atlantic Ocean, and we argue that the presented seabird series can serve as indicators to enhance the understanding of the Faroe shelf ecosystem and inform the management of both seabird populations and commercial fish stocks.

Abstract Incidental mortality via entanglement in non-selective gillnets is a known conservation issue for marine birds globally, and specifically, in the productive marine waters of British Columbia, Canada. Three alcid species are particularly susceptible to gillnet bycatch (common murres Uria aalge, marbled murrelets Brachyramphus marmoratus (listed as “Threatened” under Canada’s Species at Risk Act) and rhinoceros auklets Cerorhinca monocerata), with estimates of mortality in commercial salmon net fisheries ranging from hundreds to thousands of individuals annually. Despite the risk posed by gillnets, the population-level impacts of mortality due to entanglement have not been estimated. Therefore, we wanted to (1) understand how varying levels of gillnet bycatch may impact population growth and persistence and (2) estimate the population size needed to withstand recent estimates of entanglement mortality. We used a simulation-based approach of matrix projection models to estimate the impact of gillnet bycatch on population growth and probability of extinction within 25 years. We found that the common murre population was the most vulnerable with current rates of gillnet bycatch producing a high probability of extinction. The population size needed to withstand current estimates of gillnet bycatch was estimated at over an order of magnitude higher than the current population size, indicating bycatch mortality in Canadian waters is taking common murres breeding in the USA. Extinction risk for marbled murrelets was estimated at ∼1% in 25 years given current estimates of gillnet bycatch, contributing to other anthropogenic threats such as loss and fragmentation of nesting habitat. Rhinoceros auklets had very low extinction risk due to the large population size compared to estimates of bycatch. This study highlights the species-specific differences in the impact of bycatch on these alcid populations and the importance of moving away from gillnets toward more selective fishing methods to reduce mortality of vulnerable seabird populations.

In 2008, we built an artificial nesting construction for Common Murres Uria aalge, the Karlsö Auk Lab, on an island in the Baltic Sea (Hentati-Sundberg et al., 2012). The aim was to create an environment in which the birds could be readily monitored and accessed, and technological equipment easily installed. In this current paper, we report on murre recruitment to the Auk Lab over the first decade, assess the performance of the birds living on the lab compared to natural cliff ledges, and revisit the original research questions. We conclude that the tremendous developments in sensor technology (video surveillance, automated scales, thermal cameras, weather sensors) and artificial intelligence was not anticipated 10 years ago. Several major scientific insights, including the effects of eagle disturbances and heat stress on the murres, have come as surprises and have been driven mainly by technology's potential to deliver data with a resolution unattainable using traditional field studies. The dramatic increase in data volumes has partly been paired by automated analysis methods, but some aspects of the new technology, notably individual identification, have been more difficult than anticipated. The investment costs for information technology infrastructure, data storage, and processing capacity have also been substantial. We finish the paper by sketching out new research questions that will guide the next decade at the Auk Lab and repeating an invitation for research collaborations beyond our planned research focus.

In 2008, we built an artificial nesting construction for Common Murres Uria aalge, the Karlsö Auk Lab, on an island in the Baltic Sea (Hentati-Sundberg et al., 2012). The aim was to create an environment in which the birds could be readily monitored and accessed, and technological equipment easily installed. In this current paper, we report on murre recruitment to the Auk Lab over the first decade, assess the performance of the birds living on the lab compared to natural cliff ledges, and revisit the original research questions. We conclude that the tremendous developments in sensor technology (video surveillance, automated scales, thermal cameras, weather sensors) and artificial intelligence was not anticipated 10 years ago. Several major scientific insights, including the effects of eagle disturbances and heat stress on the murres, have come as surprises and have been driven mainly by technology's potential to deliver data with a resolution unattainable using traditional field studies. The dramatic increase in data volumes has partly been paired by automated analysis methods, but some aspects of the new technology, notably individual identification, have been more difficult than anticipated. The investment costs for information technology infrastructure, data storage, and processing capacity have also been substantial. We finish the paper by sketching out new research questions that will guide the next decade at the Auk Lab and repeating an invitation for research collaborations beyond our planned research focus.

ABSTRACTIncidental catch in gillnet fisheries has a substantial conservation impact on marine diving birds. We synthesized available marine bird bycatch data from Alaska salmon gillnet fisheries to estimate standardized bycatch rates, model factors influencing bycatch rates, and estimate total bycatch. Annual marine bird bycatch rates ranged 0.001–0.099 birds per standard net, and estimated bycatch varied widely among areas and years (111–3059 birds). Bycatch of common murres (Uria aalge) and marbled murrelets (Brachyramphus marmoratus) was highest. Bycatch rates estimated using different units of effort resulted in varying relationships, thereby creating potentially conflicting interpretations about area and gear‐type trends. Most variables were significant in only a single model, except soak duration, which indicated a higher likelihood of catching a bird as fishing duration increased. Practices that could reduce marine bird bycatch included reducing night and twilight fishing, keeping nets clean, tending nets more frequently, and keeping nets under tension.

Heligoland is an island located in the North Sea, where vegetation was almost destroyed as a result of heavy bombardment during and after the Second World War. However, over the past 70 years, the vegetation has developed from scrub towards bushy or even forested environments. This change has most likely altered habitat suitability for various organisms, including many species of ticks. Ticks can act as major vectors for various pathogens of humans and animals; thus, characterizing the occurrence of a tick population and associated microorganism on the island is of great importance in relation to public and animal health. For this characterization on Heligoland, we flagged ticks at four different locations during June 2023 and 2024. In 2024, ticks were opportunistically sampled from house pets living on the island and during the annual ringing of common murre (Uria aalge) fledglings. In total, 267 ticks were collected over the 2 years which were identified morphologically, and confirmed molecularly if needed, to four species: Ixodes ricinus (n = 132), Haemaphysalis punctata (n = 47), Ixodes uriae (n = 3), and Alectorobius maritimus (n = 85), which for the latter represents the first report in Germany. Questing tick samples positive for Borrelia burgdorferi sensu lato, Rickettsia spp., Anaplasma phagocytophilum, and Babesia spp. were found in one or both years. Subsequent sequencing showed the presence of two Rickettsia species (R. helvetica, R. aeschlimannii), multiple Borrelia species (B. garinii, B. valaisiana, B. bavariensis, B. afzelii), and two Babesia species (Ba. venatorum, Ba. capreoli). Our research highlights a diverse tick and associated microorganism population on the island, which could pose public and animal health risks that will need to be monitored in the future.

Climate change is regarded as a major threat to seabird populations globally. While the impacts on certain species are well-studied, the majority remain understudied, which may limit our understanding of the key mechanisms linking climate change to population dynamics. This information is important to identify vulnerable species and inform potential conservation responses. To address this gap, we reviewed literature on the impacts of climate change on the demography of 25 seabird species breeding in the UK and Republic of Ireland from relevant studies conducted within the wider North-East Atlantic. We found regional and species-specific variations in research effort, with the North Sea being the most studied area. The most frequently studied species were common guillemot Uria aalge (n = 35), black-legged kittiwake Rissa tridactyla (n = 29), and European shag Gulosus aristotelis (n = 25). Breeding productivity and population abundance were the primary demographic parameters investigated. The North Atlantic Oscillation and sea surface temperature were commonly used to describe climate influences, often linked to bottom-up mechanisms affecting demography through changes in prey availability. Breeding productivity was the most monitored demographic rate across species; this may lead to important mechanisms affecting other demographic rates, such as survival, being overlooked. Regional and species-specific disparities in research could bias the identification of key mechanisms. Despite these uncertainties, current literature highlights the importance of climate impacts through the food chain and severe storm events affecting seabirds. In response, climate change adaptation should prioritise management of fish stocks near breeding colonies and coastal management to protect vulnerable colonies from storm events.

Modelling the association between the El Niño Southern Oscillation and levels of legacy pollutants in Alaskan seabird eggs from 1999 to 2010

The ecological and geographical structure of bird population on the Onekotan Island was analyzed using the technique of route count along the transects of unlimited width. The avifauna of the Onekotan Island forms under the system of general zonal-landscape and altitudinal-belt patterns and unites ecological groups of marine and terrestrial species, including mountain ones ( n = 7). The zoogeographic originality of the avifauna is due to a combination of elements of the Pacific, Siberian, Far Eastern island, and Arctic faunistic complexes, as well as Siberian-American and widespread species. The species richness, bird population density, and abundance of most species decrease with altitude. There are 26 species in the avifauna of the forest belt, 17 in the subalpine belt, 14 in the alpine belt, and 29 species in the marine and coastal areas, with population densities of 559, 306, 221, and 129-223 ind./km², respectively. Dominants or subdominants in the population of terrestrial habitats include the Buff-bellied Pipit, Brown-headed Thrush, Siberian Rubythroat, Middendorff’s Warbler, Arctic Warbler, and Pine Grosbeak. Seven species numerically dominate in the population of the marine area, namely Harlequin Duck, Red-faced Cormorant, Slaty-backed Gull, and Pigeon Guillemot (in the coastal part), and Northern Fulmar, Common Guillemot, and Tufted Puffin (at a considerable distance from the coast).

Ecological patterns of the formation of bird populations on the Onekotan Island are analyzed. Route counts were used along transects of unlimited width. As many as 53 bird species were registered, including 28% revealed as ubiquitous, another 30% local, and further 32% highly local. 38 species were shown to nest. The taxonomic structure of the avifauna, represented by species from 10 orders, corresponded to the zonal and landscape features of the island’s territories located at the eastern margins of northern Eurasia. Passeriformes (38%), Charadriiformes (24%), Procellariiformes (9%) prevailed. The zoogeographic peculiarity of the avifauna was a composition of elements of the Pacific, Siberian, Far Eastern islands and Arctic faunistic complexes, combined with Siberian-American and widespread species. The avifauna of Onekotan Island, formed by a system of general zonal-landscape and altitudinal-belt patterns, unites ecological groups of marine and land species, including montane ones (n = 7). With altitude, the species richness, the bird population density, and the abundance of most species decrease. There are 26 species in the avifauna of the forest belt, 17 species in the subalpine belt, 14 species in the alpine belt, 29 species in the oceanic waters and coast, with population densities of 559, 306, 221, and 129–223 individuals/km², respectively. The similarity coefficient of the avifauna of oceanic areas is 47%, vs about 60%. of terrestrial habitats. In the population of terrestrial habitats, the dominants and subdominants include the Buff-bellied Pipit, the Brown-headed Thrush, the Siberian Rubythroat, Middendorff’s Grasshopper Warbler, the Arctic Warbler, and the Pine Grosbeak. In the population of the oceanic waters, 7 species dominate in avundance: in its coastal part, the Harlequin Duck, the Red-faced Cormorant, the Slaty-backed Gull, and the Pigeon Guillemot, vs the Northern Fulmar, the Common Guillemot, and the Tufted Puffin at a considerable distance from the coast.

Light-immersion data from geolocators can be used to estimate behavioural budgets and energetics in seabirds throughout the annual cycle. However, all methods used to categorise time spent in behaviours rely on assumptions that are difficult to validate. Additional data, such as pressure and temperature data from time-depth recorders (TDRs), can help to refine these assumptions. We explore the utility of previous methods to derive behavioural budgets from light-immersion data using a dataset from Common Guillemots Uria aalge, where individuals were equipped with both a TDR and a solar Global Location Sensor (GLS), also known as a ‘geolocator’. We compared behavioural allocations from previous methods to those derived when also using TDR data. Previous methods used light-immersion data to distinguish between time foraging, active, and resting on the water, but the addition of TDR data revealed that these activities resulted in similar light and immersion levels. It was also more difficult to differentiate between rest and flight using light-immersion data alone. However, by using insights gained from combined light-immersion and TDR data, we developed an improved method to assign behaviours using light-immersion data alone, and provide an adjusted equation to use these data to calculate energetics in Guillemots. We recommend using our approach when processing light-immersion data; however, if detailed activity budgets (particularly foraging information) are required, we recommend using higher resolution loggers, e.g. integrated light-immersion-temperature-pressure devices. Our findings are likely to be relevant for studies of other seabird species (particularly other auks) that dive and spend most of their time at sea during winter.

Proposal of Wing Control for a Common Murre Type Underwater Robot

Recent marine heatwaves have had pervasive effects on marine ecosystems, from declines in primary production to die-offs of top predators. Seabird mortalities are often observed in association with heatwaves, but population impacts are not well understood. In this work, we report the rapid mortality of approximately half of Alaska's common murre (Uria aalge) population in response to an extreme marine heatwave. Between the 7-year period before (2008-2014) and after (2016-2022) the heatwave, murre numbers plummeted 52 to 78% at 13 colonies across two large marine ecosystems. We calculated a loss of 4.00 million common murres, the largest documented wildlife mortality event in the modern era. No evidence of recovery has yet been observed, suggesting that these ecosystems may no longer support historic numbers of seabird top predators.