United States

**Abstract:**

Gulls are highly flexible in their response to dynamic atmospheric conditions across a range of terrestrial and marine environments. With their generalist diets gulls are also able to forage in many human-impacted environments such as urban and agricultural areas or fisheries, which may then render them vulnerable to changes in human behaviour. Increasingly gulls are foraging inland, which offers a very different atmospheric landscape to the marine and coastal environments they are traditionally associated with. Sources of uplift used in soaring flight, such as thermals and orographic lift, are generally less common at sea, which could mean there is a greater potential of energetic savings for gulls that choose to fly inland. However much remains unknown regarding the degree to which gulls can respond to atmospheric dynamics at varying scales over sea or land, and the degree to which it affects their foraging decisions and flight energetics. We analyse the movements of lesser black-backed gulls (Larus fuscus) in relation to atmospheric uplift over sea and land, using high-resolution GPS and accelerometer measurements alongside advanced atmospheric modelling methods. We demonstrate some of the different ways in which sources of uplift such as thermal uplift are used by gulls to save energy in flight, and how flight behaviour differs between land and sea as a result of the atmospheric environment. Gulls spend far more time soaring over land than at sea , likely due to increased surface heating over land and more orographic lift produced by landscape heterogeneity. Nevertheless, certain scenarios at sea can generate suitable soaring conditions which gulls take advantage of. Overall we show how opportunistic use of atmospheric conditions helps to facilitate soaring flight, and how the differing atmospheric conditions over land and over sea influence the energetic cost of flight.

**Authors:**

Elspeth Sage¹, Willem Bouten¹, Kees Camphuysen², Judy Shamoun-Baranes¹

¹University of Amsterdam, ²Royal Netherlands Institute for Sea Research

3rd World Seabird Conference

Fine scale flight behaviour of gulls in response to dynamic atmospheric conditions over land and sea

Welcome Seabirders!  

Welcome to Virtual World Seabird Conference 3 - vWSC3! Whether you are in your office or lab, at home, in a coffee shop or bar poaching some wifi, or at a remote field site or research vessel – we are very excited to welcome you to the third ever World Seabird Conference. 

We would like to thank ALL of you for being so patient as WSC3 was scheduled, postponed, rescheduled, revised to virtual, and scheduled again. Throughout all those iterations there was one message that remained perfectly clear – seabirders were eager to meet and share their science. If we could not meet in person then virtual it would have to be, but a 3rd WSC was something everyone wanted. That support and commitment helped the WSU Board of Directors and Member Societies sort through all of the challenges they faced to plan and hold this conference. 

The list of those that need to be thanked is long and, while we plan on recognizing many during the live closing plenary, it is important to do so here in writing as well. 

The Australasian Seabird Group was our Local Host for our plan to meet in Hobart, Tasmania. They invested substantial time and effort to find venues and plan events that we unfortunately were not able to visit. Nonetheless we appreciate their work on behalf of WSC3 and encourage all of you to thank them when you see their members in Gathertown or elsewhere during our virtual meeting. Their willingness to host created the initial excitement for WSC3 and without that our vWSC would not have been possible.

We also wish to thank the Science Program Committee, the Virtual Committee, and the Early Career Scientist Committee for their hard work planning the logistics, events, and schedule for vWSC3. These committees also had to deal with changing parameters and short timelines that made what is always a challenging task even more challenging. The Travel Awards Committee also invested time and effort in developing procedures for awarding travel funds that ultimately would not be implemented. 

Our ability to shift from an in-person to a virtual meeting, and to do so in a way that would be financially feasible, was due to the effective efforts of The International Fundraising Committee and to our financial sponsors. The IFC raised funds to support WSC3 and then, through the good relationships they built with sponsors, ensured we could re-envision how those funds could be used to support a virtual conference that would be affordable and high-quality.

We all owe the WSU Board of Directors and the Representatives of the Member Societies a great deal of thanks. They are the ones who manage the WSU and, for the past 18 months, have had to have a series of challenging meetings and conversations, have had to make a series of difficult choices, have had to do all of that while considering the short- and long-term health of WSU and the World Seabird Conferences, and did this while also managing their own challenges at their day jobs. We are grateful for their diligence, patience, foresight, and throughout all of the meetings, their collegiality. Also – a 6-year term is quite a commitment!

There would not be a WSC3 without a successful WSC1 and WSC2. Thanks go to the Pacific Seabird Group for their support of WSC1 in Victoria, Canada, and to the African Seabird Group for their support of WSC2 in Cape Town, South Africa. In each of these endeavors and for our current conference we were fortunate to work with a dependable and trustworthy partner in Podium Conferences. Michelle Smith and Marischal de Armond have become valued members of our team and have not only helped us plan conferences but have assisted and advised the WSU Chairs and Board on issues above and beyond conference planning. 

As we embark on our vWSC3 week we extend to all of you our thanks for showing up, for being patient, and most importantly for the work you do with seabirds. We are all part of a unique, global community that shares an interest, a fascination, and a passion for birds that make a living in our world’s oceans. We have advanced the science, conservation, and management of seabirds as well the ecosystems they inhabit. We are consistently impressed and motivated by the work you do. 

The WSU formed in 2010 because we saw the need for a global organization to address challenges at a global level. Over the past 11 years WSU has grown, adapted, and evolved to become the community that this week is making vWSC3 a reality. Enjoy the week, appreciate and support the friends and colleagues you have made in the community, and if you see us in a virtual hallway please stop and say hello! 

Thank you for the opportunity to serve all of you and the WSU over the past few years,

Nicholas Carlile, Interim Chair, WSU<br>
Patrick Jodice, 2nd Chair of the WSU<br><br>

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Join us for four days of science, networking and virtual engagement with delegates from around the world!

symposium

**Abstract:**

Technological advances in biologging in recent years have opened several new avenues to study the at-sea behaviour of seabirds. The efficiency and size of these loggers have been improved to such an extent that fine-scale behavioural data can be recorded for extended periods. This is particularly useful when studying the at-sea behaviour of far-ranging Procellariiformes, a task that is often logistically challenging. We used a combination of biologgers (GPS, video camera and inertial measurement units [IMUs]) to study the flight behaviour of several procellariiforms breeding on sub-Antarctic Islands in the southern Indian and Atlantic Oceans, in varying wind conditions. The IMUs (including tri-axial accelerometers and magnetometers) allowed us to infer fine-scale (40 Hz) movement patterns while the video cameras were used to ground-truth the IMUs and to extract bank angles from recorded flights. Dynamic soaring was identified through sinusoidal curves in magnetometer axes (independent of acceleration), while individual flaps were identified from the heave axis of the accelerometer. GPS loggers provided hourly location estimates, which were used to determine local wind conditions from satellite data. Albatrosses displayed dynamic soaring during most flights, with the duration of cycles decreasing and bank angles increasing with increasing wind speeds. By coupling flapping and roll angles we show that flapping, on occasion, occur at the upper turn of the dynamic soaring cycle, a period previous thought devoid of flaps. These results also suggest possible sexual differences, where males seem to flap more often than females and limit their take-offs to favourable wind conditions. This study shows how multiple fine-scale loggers can be used to gain insights on how seabirds of varying body sizes are able to travel vast distances in the dynamic Southern Ocean environment.

**Authors:**

Stefan Schoombie¹, Rory Wilson², Peter Ryan¹

¹FitzPatrick Institute of African Ornithology, ²Swansea University

Fine-scale flight: the effect of wind on flight patterns of dynamic soaring seabirds

**Abstract:**

Bycatch of seabirds in longline fisheries includes mortalities (during setting) and live captures (mainly during hauling). The proportion of injured live-caught birds that later die is unknown, complicating efforts to quantify impacts of fisheries, particularly as live-capture rates will probably increase with vessels adopting night setting as a mitigation measure. Over a 26-year period at South Georgia, foul-hooking indices - birds with embedded hooks or entangled among 10 000s checked at the colony - were broadly similar in wandering albatrosses and giant petrels, an order of magnitude lower in black-browed albatrosses and nil in grey-headed and light-mantled albatrosses. This likely reflected differing degrees of overlap with fisheries and interaction with gear during hauling. Indices peaked in the early 2000s, then declined, broadly corresponding with changing fishing practices - the lagged effect of a seasonal fisheries-closure, introduction of a new fishing system, reduced effort in some demersal fisheries, general improvements in bycatch mitigation - indicating that foul-hooking indices at colonies can reflect relative risk for different species over time, and be a useful adjunct to vessel-based monitoring of live-capture rates. Taking into account age and status when reported, and annual survival probabilities in the wider population, subsequent survival of live-caught and released wandering albatrosses was around 40% of that expected for the wider population. This has major implications for ecological risk assessments that seek to determine the impacts of fisheries on seabirds, as most do not currently consider deleterious impacts of live capture.

**Authors:**

Richard Phillips¹, Andrew Wood¹

¹British Antarctic Survey

Variation in live-capture rates of albatrosses and petrels in fisheries, post-release survival and implications for monitoring and management

**Abstract:**

The study of the use of space in seabirds had increased exponentially due to the use of biologging devices and the statistical techniques to extract and analyze large datasets. One of these statistical techniques is the Hidden Markov Models (HMM), which allow the identification of different behaviors of birds during their trips. Currently, few studies have been carried out to evaluate the classification accuracy of HMMs at different sampling frequencies. In this sense, the goal of the present study is to quantify the effect of sampling frequencies on the identification of foraging areas using HMMs in two tropical seabirds (31 trips of Sula leucogaster and 16 trips of Phaethon aethereus), with different GPS sampling frequencies (1/min and 1/15min, respectively). In addition, in both species we used pressure sensor data where dives were identified, used to validate HMM results. To identify foraging states we fitted HMMs to GPS datasets from both seabirds. To validate the classification accuracy of the HMMs, the data classified as foraging were contrasted with the dives and were calculated the precision, sensitivity and specificity measures. Subsequently, kernel densities were estimated for foraging and dives datasets and the overlap between them was calculated as a proxy for overall accuracy. Results showed that the classification ability of the HMMs was 81% for S. leucogaster, while for P. aethereus it was 48%. On the other hand, the kernel overlap values of foraging and diving were higher than 95% for both species. The present study demonstrated that the classification ability of HMMs in data with low sampling frequency (i.e. 1/15min) could present a high error percentage at the individual level. However, the high kernel overlap value (>95%) shows that at the population level it is possible to use low sampling frequencies to identify foraging areas.

**Authors:**

Fiorella Vilela¹, Sophie Bertrand², Marcio A. Efe³, Leandro Bugoni⁴, Guilherme T. Nunes¹

¹Universidade Federal do Rio Grande do Sul, ²Institut de Recherche pour le Développement (IRD), ³Federal University of Alagoas, ⁴Universidade Federal do Rio Grande

Effort of sampling frequency on foraging trip segmentation in tropical seabirds

**Abstract:**

The migratory behaviour of the Yelkouan Shearwater, a seabird endemic to the Mediterranean Sea and classified 'Vulnerable' according to IUCN criteria, remains poorly understood to date. While Yelkouans of various Mediterranean origins (Malta, France, Greece) have been sighted occasionally from summer to autumn as far as the Black Sea, others have been observed in the southern Mediterranean waters. Here we describe for the first time the post-breeding journeys of 11 adults from a colony in Lastovo Archipelago, central Adriatic (Croatia) which we equipped in late June 2021 with ultra-light GPS-GSM loggers that are still active at the time of this writing. The results display a strong variability in the journeys of individuals from the same nesting site. In the space of only six weeks, three adults had already traveled over 2500 km, following the same route although days apart, to reach the pelagic waters of the Black Sea. At least one of them was tracked all the way till the entrance of the Azov Sea - a major spawning ground for anchovies. Others stopped their journey - for weeks at least - in islands of the Aegean Sea, home to many yelkouan nesting colonies. Other individuals kept foraging between the Italian and Croatian coasts of the Adriatic Sea, while others limited their flights to the vicinity of their nests in the Lastovo archipelago. Our preliminary conclusions underline the similarity of the long, rather precise, migratory route followed by the yelkouans to reach the Black Sea. Our study raises many further questions: to begin with, what is the precise stimulus that triggered the start of their respective migration?

**Authors:**

Loriane MENDEZ¹, Sven Kapelj², Paula Moschella¹, Frederic Briand¹

¹CIESM (Mediterranean Science Commission), ²Association BIOM

The summer migration of the Yelkouan Shearwater (Puffinus yelkouan) from a single island in Croatia

**Abstract:**

The likelihood of conservation strategies being successful increases when the varying ecologies of an animal during all life-history stages are considered, particularly during those which the animal is more vulnerable. For example, penguins are land bound and unable to feed for several weeks when they undergo their annual catastrophic moult. If they are unable to accumulate sufficient fat stores before and after this critical life history stage, they are unlikely to survive or it could have adverse carry-over effects into the following breeding season. Over the past 20 years, the population of the Endangered African penguin Spheniscus demersus has followed the declining trend in the availability of their main prey, sardine Sardinops sagax and anchovy Engraulis encrasicolus. Subsequently, to improve prey availability, conservation efforts have focused on spatial management strategies to reduce resource competition with purse-seine fisheries during the breeding season. To date, these spatial management strategies have not considered the spatial distribution of the penguins during other critical life-history stages. Using GPS tracking data collected between 2012 and 2019, we identify important foraging areas for pre- and post-moult African penguins at three of their major colonies: Dassen Island and Stony Point (Western Cape) and Bird Island (Eastern Cape). The at-sea distribution of non-breeding adults (c. 600 km from colony) was far greater than that observed for breeding birds (c. 40 km from colony) and varied considerably between sites, years and pre- and post-moult stages. However, waters within 20 and 40 km of their breeding colonies were intensively used and represent important foraging areas to non-breeding birds. Our findings identify important marine habitats for non-breeding African penguins and provide support for the expansion of fisheries-related spatio-temporal management strategies to help conserve African penguins outside the breeding season.

**Authors:**

Tegan Carpenter-Kling¹, Andrew deBlocq¹, Christina Hagen¹, Craig Harding², Taryn Morris¹, Lorien Pichegru³, Peter Ryan², Jennifer Roberts², Ross Wanless¹, Alistair McInnes¹

¹BirdLife South Africa, ²University of Cape Town, ³Nelson Mandela University

Surviving catastrophe: important marine area use of non-breeding African Penguins supports proposed conservation strategies for breeding birds

**Abstract:**

Post-breeding migrations from temperate latitudes allow animals to improve survival by tracking food supplies and seeking out milder climatic conditions. In long-lived species such as seabirds, which have several years of immaturity before becoming breeders, successful migration is a key parameter influencing long-term population dynamics. Most seabird tracking studies have focused on adult behaviour during the breeding season but developments in tracking technology are now opening up opportunities for exploring behaviour during earlier life stages and larger-scale movements during migration. Adult Northern gannets show individual heterogeneity in the timing and route choice of their southerly migration as well as in their overwintering locations. However there is currently no data on the behaviour of juvenile gannets which fledge at approximately 13 weeks, after which they are entirely independent of their parents. Tracking their behaviour during this early life stage is vital for understanding dispersal and survival and may have consequences for conservation measures, which are currently based solely on data for adults. We attached Argos GPS-PTTs to 42 fledgling gannets on the Bass Rock, Scotland in 2018 and 2019. Here we present the first GPS and satellite tracking data for these birds during their initial few weeks at sea, providing new insights into the timing, route choices and staging grounds used by birds on their maiden migration.

**Authors:**

Jude Lane¹, Keith Hamer¹

¹University of Leeds

Post-fledging movements, mortality and migration of juvenile northern gannets

**Abstract:**

Increasingly in seabird research, individual differences in life history traits are being described within populations of both pelagic and nearshore species. Among these traits is partial migration, whereby some individuals relocate from the breeding grounds on a seasonal basis while others remain sedentary year-round. Importantly, as described by obligate partial migration, individuals can alternate between sedentary and migratory strategies on an interannual basis. Despite the relatively widespread incidence of partial migration in avian species, mechanistic causes underlying this behavior remain poorly understood, especially in tropical and subtropical systems. We evaluated three competing hypotheses driving partial migration in brown pelicans (Pelecanus occidentalis) tracked with GPS transmitters in the South Atlantic Bight, USA. These include (1) competitive release (i.e., intraspecific competition for limited resources drives migration of subordinates), (2) fasting endurance (i.e., individuals unable to meet energetic demands will migrate), and (3) thermal tolerance (i.e., migratory probability is directly influenced by thermal extremes). We evaluated these hypotheses in relation to intrinsic factors such as sex, body condition, and reproductive status and extrinsic factors such as environment, climate, and a measure of anthropogenic food subsidy. While prior evidence suggests that pelican migration in other parts of their global range (e.g. Gulf of Mexico) is influenced by density dependence, we highlight differences in colony sizes, behavior, and coastal geomorphology in the South Atlantic Bight that play a role in determining migratory probability for this region. We subsequently modeled how migration probability may change under various climate change scenarios along with concomitant changes in non-breeding distribution, and underscore the need to examine drivers of animal movement throughout the range of a given species.

**Authors:**

Bradley Wilkinson¹, Patrick Jodice²

¹Clemson University, ²USGS South Carolina Cooperative Fish and Wildlife Research Unit

Brown pelicans as a model of partial migration in nearshore seabirds

**Abstract:**

Polar systems of avian migration remain unpredictable. Here we report on three related predatory seabird species that divided across four oceans following sympatric breeding at a central Canadian high Arctic nesting location. Using telemetry we tracked Pomarine Jaeger (Stercorarius pomarinus; POJA, n=1) across the Arctic Ocean to the western Pacific Ocean; Parasitic Jaeger (S. parasiticus; PAJA, n=4) to the western Atlantic Ocean, and Long-tailed Jaeger (S. longicaudus; LTJA, n=2) to the eastern Atlantic Ocean and western Indian Ocean. We also report on extensive nomadic movements over ocean during the post-breeding period (19,002 km) and over land during the pre-breeding period (5,578 km) by Pomarine Jaeger, an irruptive species whose full migrations have been a mystery. Understanding the routes and migratory divides of birds nesting in the Arctic region has implications for understanding both the glacial refugia of the past and the Anthropocene-driven changes in the future.

**Authors:**

Autumn-Lynn Harrison¹, Paul Woodard², Mark Mallory³, Jennie Rausch²

¹Smithsonian Conservation Biology Institute, ²Canadian Wildlife Service, ECCC, ³Acadia University

Sympatrically-breeding congeneric seabirds (Stercorarius spp.) from Arctic Canada travel to four oceans

**Abstract:**

Feathers play an important role in many aspects of avian ecology, including sexual selection, thermoregulation and flight. However, several external stressors can negatively impact plumage condition. Birds preen their feathers to maintain feather integrity throughout the year. For seabirds, preening is especially important to ensure waterproofing of the plumage. However, due to the difficulty of observing seabirds at sea, little is known of the time and energy expended in preening and how this may impact other activities in these species. In the present study, bird-borne video and tri-axial accelerometer data loggers were used to investigate preening in Australasian Gannets (Morus serrator) from two colonies in south-eastern Australia. Gannets spend a substantial proportion of their time at sea preening (25.5 ± 1.7%). No significant differences in preening activity were observed between the 3 years of study or between colonies. Average Vectorial Dynamic Body Acceleration (VeDBA, a proxy for energy expenditure) was significantly higher during preening (0.34 ± 0.02 g) than resting (0.25 ± 0.02 g), but less than for flying or foraging. These results highlight the importance of preening in terms of time and energy in this species. Furthermore, a positive relationship between the number of dives and at-sea preening suggests a negative impact of diving on plumage integrity and, thus, a potential additional time and energy constraint during periods of reduced food availability.

**Authors:**

Louarn Fauchet¹, Thomas Cansse¹, John P.Y. Arnould¹

¹Deakin University

The importance of preening behaviour in the at-sea time budget of Australasian gannets

**Abstract:**

Long-term monitoring data of seabirds have revealed the annual trend of mercury exposure in seabirds that are known to play a role of biovectors transporting methylmercury from the ocean to the land. However, it is unclear how wintering distribution and habitat affect the efficacy of seabirds as mercury biovectors. To address this issue, we tested whether seabirds that fly through and hence feed in regions of high [Hg] have a higher biovectors capability, and whether their at-sea behavior is more heavily impacted. To time exposure, we exploited the differential turnover rate of different bird tissues in storing Hg until they reach their colony in the Spring; to assess Hg biotransport, we sampled terrestrial plants at their colony; to assess wintering behavior, we monitored stable isotopes of nitrogen (δ15N; trophic position) and equipped birds with data loggers (geolocation and activity). By contrasting two areas on both sides of the North Pacific of high (Japan; n = 10) and low (Alaska; n = 11) Hg emissions and using the Rhinoceros auklet as a model species, we show that all sampled individuals have high [Hg] (0.3-11.4 μg g-1) that are ultimately deposited at their colony via feces. While exposure levels of auklet tissues were associated with environmental contamination levels during wintering, at-sea behavior was transient Alaskan birds, but long-lasting in Japanese birds. These results not only indicate that seabirds can be used as a tracer of large-scale Hg emission rates, but also that seabirds may suffer long-term behavioral changes when subjected to higher Hg during winter.

**Authors:**

Akiko Shoji¹, Kyle Elliott², Yutaka Watanuki³, Stéphane Aris-Brosou¹, Shannon Wheeler², Scott Hatch⁴

¹University of Ottawa, ²McGill University, ³Hokkaido University, ⁴Institute for Seabird Research and Conservation

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Fine-scale flight: the effect of wind on flight patterns of dynamic soaring seabirds

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Devil's in the details: A multi-colony perspective on the foraging ecology of western gulls

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