United States

**Abstract:**

Both professional and citizen-science field work often generate uncertain sample measurements. Definitive age and sex determinations can be notoriously difficult and/or costly to ascertain for specific individuals in the field, and even correct species identification can be problematic in citizen-science endeavours. While a variety of statistical techniques exist for quantifying such uncertainty at the population or sample level, when this uncertainty exists at the level of the individual datum, analysts are either forced to treat the unit-level information as definitive or discard it altogether. Either approach can introduce bias into subsequent sample estimates and necessarily mischaracterizes their associated measures of uncertainty. In this presentation, we will discuss random-variable-valued measurements, a new approach that we have developed to directly incorporate the sample-unit-level uncertainty of measurements into traditional data analysis, and introduce software for easy implementation. Our approach allows analysts to properly utilize field measurements on individuals that are both definitive and tentative (e.g. partial/uncertain sex or age measurements), improving the accuracy and reliability of resulting inferences that are crucial for the quantification of seabird population demographics.

**Authors:**

Edward Kroc¹, Louise Blight²

¹University of British Columbia, ²Procellaria Research &amp; Consulting

3rd World Seabird Conference

Methodological improvements in uncertain classification of individual-level demographic measurements: Improving reliability of inferences from citizen-science and field data

**Abstract:**

Both professional and citizen-science field work often generate uncertain sample measurements. Definitive age and sex determinations can be notoriously difficult and/or costly to ascertain for specific individuals in the field, and even correct species identification can be problematic in citizen-science endeavours. While a variety of statistical techniques exist for quantifying such uncertainty at the population or sample level, when this uncertainty exists at the level of the individual datum, analysts are either forced to treat the unit-level information as definitive or discard it altogether. Either approach can introduce bias into subsequent sample estimates and necessarily mischaracterizes their associated measures of uncertainty. In this presentation, we will discuss random-variable-valued measurements, a new approach that we have developed to directly incorporate the sample-unit-level uncertainty of measurements into traditional data analysis, and introduce software for easy implementation. Our approach allows analysts to properly utilize field measurements on individuals that are both definitive and tentative (e.g. partial/uncertain sex or age measurements), improving the accuracy and reliability of resulting inferences that are crucial for the quantification of seabird population demographics.

**Authors:**

Edward Kroc¹, Louise Blight²

¹University of British Columbia, ²Procellaria Research & Consulting

poster

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!

**Abstract:**

The islets of the Tubbataha Reefs Natural Park serve as an important breeding ground for seabirds. This study aimed to determine how the variability in climate has influenced the population dynamics and phenology of six resident breeding seabird species in the park: Red-footed Booby, Brown Booby, Great Crested Tern, Sooty Tern, Brown Noddy and Black Noddy. Survey methods followed Bibby et al. (2002). The data suggests that the increase in sea surface temperature in the area did not negatively influence the inter-annual variability of the seabird population. However, during El Niño events the effects of sea surface temperature changes to Great Crested Tern, Sooty Tern, and Brown Noddy were significant. Chlorophyll a concentration, which was used as a proxy for prey availability, could not be linked to the presence of adult birds, but it reliably predicted the breeding phenology of Great Crested Tern and Sooty Tern in the area. The peak of sea surface temperature was strongly linked to the start of egg-laying for the Great Crested Tern. The future changes in climate could possibly influence these environmental factors and consequently affect the phenology as well as the population of the seabird species in the area. The future occurrence of long and strong El Niño episodes might delay the breeding of these seabirds. The result of this and further studies will help park management better understand seabirds and come up with effective conservation strategies for the species.

**Authors:**

Maria Retchie Pagliawan-Alaba¹, Angelique Songco¹, Arnold van Vliet², Arne Jensen³, Rowell Alarcon¹, Gerlie Gedoria¹

¹Tubbataha Management Office, ²Wageningen University and Research Centre, ³Wild Bird Club of the Philippines

The effects of climate variability on seabirds breeding in the Tubbataha Reefs Natural Park, Philippines

**Abstract:**

Coral reefs cover less than 0.2% of the Ocean surface but represent major biodiversity reservoirs. They contribute to the economic development of many countries through tourism and fishing activities and play an essential role in protecting coastal areas. However, 70-90% of coral reefs could disappear by the end of the century if the temperature increases by only 1.5°C. As recent studies suggested a potential cross relationship between the health of coral reefs and those of island seabirds, we explored seasonal variations in the across-taxa pattern of nutrient enrichment along the coasts of two remote islets hosting dense seabird colonies. Our two sites lie in the Entrecasteaux reefs, in the Coral Sea Natural Park which host seabird colonies of world significance. At each site, we sampled seawater nutrients, macroalgae and corals along a coast-sea transect and at a reference reef distant from 9km. We repeated this sampling twice in 2017 (in austral winter and summer) to identify potential seasonal variations. Nitrogen isotopic values (δ15N) of the different samples were measured as a proxy of guano-derived nutrient assimilation. A consistent spatial pattern of increasing NOx concentrations and δ15N values near the islet (25m of the shore) compared to more distant stations (200m of the shore) was observed at both reef sites and sampling seasons. The δ15N enrichment ranged from 2.5 to 5? in the coral Pocillopora damicornis and from 4 to 7? in the macroalgae Halimeda sp. This study thus demonstrates that land-originated nitrogen reaches both primary producers and consumers in coastal reefs no matter the season. Results are discussed in light with the isotopic signature of seabirds' guano and the mechanisms underlying the transport of nutrients from guano to coastal reefs, providing an ecosystem view of the cross relationship between seabirds and reefs' health.

**Authors:**

Martin THIBAULT¹, Fanny Houlbreque¹, Eric Vidal¹, Anne Lorrain²

¹ENTROPIE (IRD), ²LEMAR (IRD)

Healthy seabirds, healthy reefs? Enrichment patterns in coral ecosystems by guano-derived nutrients

**Abstract:**

Species that inhabit spatially-distinct regions at different stages of their lifecycle pose challenges to conservation managers, particularly when distributions span international or jurisdictional boundaries. Despite the importance of non-breeding habitat to the persistence of individuals and species, there remains limited information on the habitat requirements of many species during the non-breeding period. We used global positioning system tracking devices to determine the non-breeding movements of Great Frigatebirds, Fregata minor, and Lesser Frigatebirds, F. ariel, across much of Southeast Asia. These data were analysed with MaxEnt modelling to identify important habitat features for non-breeding frigatebirds and inform priorities for addition to the marine protected area (MPA) network. Models with the greatest predictive performance were influenced strongly by bathymetry. Predicted habitat suitability was greatest in shallow waters. Similarly, warmer waters had greater predicted suitability during the wet season. The existing protected area network contains only a small proportion of habitat identified as suitable or optimum for non-breeding frigatebirds. This is of particular concern given that some parts of the region's marine environment are among the most heavily human-impacted in the world. Currently proposed additions to the MPA network will likely provide negligible benefits to non-breeding frigatebirds due to their small extent relative to suitable habitat and their limited or complete lack of overlap with areas predicted to represent optimum habitat. Our findings can be used to make targeted additions to the MPA network to efficiently increase the representation of suitable and optimum habitat for non-breeding frigatebirds in the MPA network. Such an approach will likely provide benefits to frigatebird populations tracked in the present study as well as those dispersing to the study region from other ocean basins.

**Authors:**

Rowan Mott¹, Ashley Herrod², Rohan Clarke¹

¹School of Biological Sciences, Monash University, ²Moonlit Sanctuary

Transboundary priorities for protection of frigatebird non-breeding habitat in a heavily impacted region

**Abstract:**

Low-level islands around the globe are predicted to face a "range of coastal hazards" driven by sea level change throughout the 21st century. These risks include the permanent submergence of land areas due to higher sea level, accelerated coastal erosion and the rise in frequency and intensity of flooding events, all of which threaten the future biodiversity and functioning of insular ecosystems. On tropical coral reef islands (CRI, low-level islands formed through reef construction and the accumulation of coral debris), sea level change will likely reduce breeding habitat availability for multiple seabird species, adding to the effects of long-known ecological disruptions (species invasions, reef decline, decrease in prey availability). However, the extent to which seabird populations in CRI might be affected by sea level change remains broadly uncharacterized due to limited understanding of the large-scale demography and behavioral adaptability of tropical seabird species, along with overall poor knowledge of the geomorphology dynamics of islands threatened by submersion and/or coastal erosion. Here, we present an overview of current information gaps in the assessment of global distribution and vulnerability of seabirds breeding on CRI. Using New Caledonia (South-West Pacific) as a baseline example, we then discuss a prospective research framework for (1) aggregating monitoring data on CRI seabird populations, (2) assessing natural and anthropogenic drivers of colony distribution and (3) identifying long-term conservation and restoration targets in a context of future sea level change. This talk aims to highlight the need for more comprehensive, multiscale and collaborative seabird monitoring on vulnerable, low-lying islands as a tool to prioritize key conservation sites in the inter-tropical region and shape relevant mitigation strategies.

**Authors:**

Tristan Berr¹, Alexandre Millon², Poetea Guehenneuc³, Matthieu Le Corre⁴, Éric Vidal⁵

¹Institut de Recherche pour le Développement, Université de Nouvelle-Calédonie, ²Aix Marseille Université, Institut Méditerranéen de Biodiversité et d'Écologie, ³Université de Bordeaux, ⁴Université de la Réunion, ⁵Institut de Recherche pour le Développement

Seabird conservation priorities: the case of coral reef islands

**Abstract:**

As bite-sized plastics increasingly invade our oceans, the past decade has seen a rise in studies seeking to understand how plastic ingestion affects the health of wildlife. Seabirds are well represented among plastic-ingesting taxa; with 44% of 409 species currently recorded to ingest plastic, a figure predicted to increase to 99% of species by 2050. Tubenoses (Procellariiformes) are especially well known for plastic-eating behaviour; 63.2% of 144 species are currently known to ingest plastic, with frequencies of up to 100% of individuals in some populations. Though scientists perceive hundreds of health impacts of plastic ingestion on vertebrate animals, few studies find lethal outcomes and research attention has shifted to identifying sub-lethal effects. Sub-lethal health concerns include both physical effects on nutrition, damage to the gut, gut dysbiosis; and chemical or toxicological effects from exposure to plastic-associated (additive and adsorbed) metals and hydrophobic organic chemicals, including toxicity and endocrine disruption. Evidence for statistically significant plastic-associated effects is well-supported, but how many of these effects have demonstrated evidence for health consequences at an organism level or an ecologically relevant scale? Does the ingestion of non-lethal plastic loads cause widespread health consequences for individuals and populations? Is ingestion of plastic no different to ingestion of naturally occurring indigestible items? Or does the evidence lie in a middle ground somewhere between these oft argued extremities. Here we summarise the current state of knowledge of sub-lethal health effects of plastic ingestion in seabirds. We argue that multiple potential pathways between plastic and the measured effect, over-interpretation, exposure concentration and confounding at the root of the disagreement between scientists. We recommend learning from more established fields such as toxicology to establish good practice for reporting on sub-lethal health effects of plastic ingestion in seabirds, with the aim of transparently presenting evidence in a format which disentangles the demonstrated from the perceived.

**Authors:**

Lauren Roman¹, Britta Denise Hardesty¹, Chris Wilcox¹

¹CSIRO

Sub-lethal health effects of plastic ingestion in seabirds: Disentangling the demonstrated from the perceived

**Abstract:**

Continued warming of the Earth's atmosphere is having a range of ecological, behavioural and physiological impacts on seabirds. The effects of changes in sea surface temperatures on seabirds are well-documented, but the effects of high ambient temperatures on land are not. Like all penguins, moult in Little Penguins is 'catastrophic', with all feathers shed and replaced in ~18 days. As they do not have adequate insulation and waterproofing to forage at sea, they are constrained to land in some of the hottest parts of the year. Long-term survival analysis suggests that adult mortality is greatest in years when high ambient temperatures are paired with low humidity during moult. Given current climate projections, successful management of Little Penguins requires a better understanding of the physiological processes and habitat features that influence mortality events. In this study we aimed to identify which birds are most at risk of heat stress during moult, and why. Using a novel approach to field respirometry, we investigated thermoregulatory costs of moulting birds in response to ambient temperature and humidity. Our results predicted that penguins in early stages of moult would be most affected by heat exposure, as they displayed a significant increase in metabolic rate at higher temperatures compared to mid and late moult birds. During a heat wave in 2019, the greatest mortality event of moulting adult Little Penguins on record occurred at Phillip Island in south-Eastern Australia. As predicted, all recorded deaths were birds in early stages of moult. We are currently quantifying the microclimates of burrows and vegetation types and investigating how birds are using structural habitat during extreme weather events. Results will help determine how Little Penguins are currently coping with extreme temperatures on land, and identify adaptation options most likely to reduce negative climate change impacts for the species across their distribution.

**Authors:**

Lauren Tworkowski¹, Peter Dann², Ursula Ellenberg¹, Kylie Robert¹

¹La Trobe University, ²Phillip Island Nature Parks

Impacts of terrestrial heat waves on survival of little penguins during moult

**Abstract:**

Seabirds on islands in the California Current are often heralded as indicators of ocean climate variability. However, far less is known about the responses of seabirds at time scales of hundreds to thousands of years. Near the southern end of the California Current in the Channel Islands National Park, two small nocturnal alcids breed on Santa Barbara Island. This includes the zooplanktivorous Cassin's Auklet (Ptychoramphus aleuticus) as well as the more generalist Scripps's Murrelet (Synthliboramphus scrippsi). Adults of both seabirds are consumed by Barn Owls (Tyto alba), and one particular owl roost in a sea cave contains a record of accumulated prey bones spanning at least the last ~1500 years. As part of a larger ongoing project detailing the faunal remains from the cave, we compared the isotopic niche dynamics for auklets and murrelets over the last millennium. We used stratigraphy and AMS 14C dated samples to determine ages of the seabird bones and extracted bone collagen for stable isotope analysis (𝛿13C and 𝛿15N). We also compiled data on marine paleoclimate to determine how changing conditions may have affected niche dynamics and partitioning between the two alcids. We also evaluated the impacts of more recent historical changes to the island such as the introduction of non-native plants and animals and the advent of commercial fisheries. Finally, we discuss these findings in the context of ongoing climate change and implications for the future.

**Authors:**

Sarah Thomsen¹, Paul Collins², René L. Vellanoweth Vellanoweth³, Amira Ainis⁴, Jessica Rodriguez³, Santos Ceniceros³, Tara Smiley⁵, Jen Cotton⁶, Rebecca Terry¹

¹Oregon State University, ²Santa Barbara Museum of Natural History, ³California State University, Los Angeles, ⁴University of Oregon, Eugene, ⁵Indiana University, ⁶California State University Northridge

A thousand years of change in the California Current and the isotopic niches of two alcids

**Abstract:**

Human disturbance of seabird colonies is increasing globally, activities such as development can have direct negative effects on the breeding grounds. Being flightless, penguins are at higher risk of vehicle collisions in developed areas. Mitigation of these impacts need to be adapted to individual species and situations. Phillip Island, Australia is a successful story of conservation of Little penguins Eudyptula minor. Conservation initiatives are funded by ecotourism to the Penguin Parade®, which attracts over 800,000 paid visitors per year. The carpark built to accommodate around 600 vehicles per night also had Little penguin breeding burrows amongst the parking bays. This unwanted interaction resulted in 21 vehicle collisions with Little penguins within the parking areas between 2012 and 2017. As part of the redevelopment of the visitor centre in 2018, penguins were excluded from the future parking areas to mitigate this risk. While fencing is an effective deterrent to keep Little penguins out, gates across entry/exit roads to allow cars and buses through were not a practical option. Here we investigated the efficacy of modified cattle grids, fauna grids, to restrict the movement of Little penguins. Automated camera-traps were used to observe the animals' behaviour when interacting with the fauna grids. Little penguins approaching the grids were classified into: refusing to cross, unsuccessful crossing attempt, or successful crossing. Initial analysis showed most penguin approaches were unsuccessful crossing attempts, with a smaller proportion refusing to cross, and no successful crossings observed. Our results suggest that fauna grids can be used to effectively restrict the movements of Little penguins and exclude them from unwanted areas. We propose the use of fauna grids as an effective tool to help mitigate road mortality of Little penguins, which may be applicable for other flightless bird species.

**Authors:**

Leanne Renwick¹, Andre Chiaradia¹, Ross Holmberg¹, Damian Prendergast¹

¹Phillip Island Nature Parks

Using fauna grids to prevent penguin mortality

**Abstract:**

Tītī, sooty shearwater (Puffinus griseus) breed in New Zealand, the majority now confined to offshore islands with limited introduced predators. Outside the breeding season they migrate to the North Pacific. While abundant, P. griseus are classified under the NZ Threat Classification System as nationally At Risk, In Decline and are threatened at their breeding sites by introduced mammal predation and land use change and at sea by bycatch from the fishing industry and changes to food source from climate change and fisheries competition. Otago has the largest remaining colonies of P. griseus on mainland New Zealand, however these colonies are declining and remain threatened by introduced species predation. Forest & Bird is attempting to maintain a colony at Sandfly Bay Wildlife Reserve, we present results from five seasons of colony monitoring where predator control initiated in 2017. A trained conservation dog was used to identify active burrows at early incubation and again at late chick stage. These burrows were monitored by trail camera and in years with successful fledging, chicks were banded and PIT tagged prior to fledging. In all years an estimated 150 burrows showed activity, but in four of the five years only a small percentage of these had breeding pairs. This is uniform across the remnant colonies we have studied, highlighting the potential for conservation dog monitoring of burrowing seabird colonies with low breeding occupancy. Seven predatory introduced mammals have been recorded and while the trap network has caught a range of these, cameras show that tītī chicks were still predated and in three consecutive seasons no chicks fledged. Successful fledging was recorded for the first time in season four, and with greater success in season five, resulting in 81 chicks banded in two seasons. Despite breeding failure in three out of five seasons, low mortality of adults has been recorded. Our results show the challenges associated with effectively protecting P. griseus breeding colonies from introduced mammal predation and that an expanded range of ethically approved predator control tools, that avoid catching other valued native species, are required. The persistence of P. griseus colonies at mainland sites calls for establishing effective management and monitoring techniques which can be used further afield. Furthermore, New Zealand has an aspirational goal of being "Predator Free by 2050"; our results demonstrate the ambition of this aspiration.

**Authors:**

Francesca Cunninghame¹, Graeme Loh¹, Paul Gasson², David Bowden¹

¹Royal Forest & Bird Protection Society, ²Independent

Challenges associated with introduced predator control to protect a remnant mainland colony of titi, sooty shearwater (Puffinus griseus) in Otago, Aotearoa New Zealand

**Abstract:**

Ecosystem monitoring programs that aim to support the maintenance of biodiversity and ecosystem function require a sound knowledge of species composition and food web linkages. This information provides a foundation for assessing ecosystem changes. Seals and seabirds respond to changes in the availability of lower trophic levels, making these predators ideal indicator species to monitor change. Dietary studies provide a mechanism to assess these ecosystem changes as well as the marine biodiversity of a region. DNA metabarcoding of predator scats is a non-invasive tool that allows the simultaneous investigation of the diet of different predator species, increasing our understanding of ecosystem connectivity and food web structure. However, the success of these programs relies on careful selection of candidate species, utilisation of appropriate molecular markers, availability of reference sequences and incorporation of DNA data into food web networks. By simultaneously studying the diet of various predators on Macquarie Island, we aim to develop a marine ecosystem monitoring framework using scat DNA to assess biodiversity of prey species in the sub-Antarctic. Through the collation of baseline and new dietary data, we will provide a sound foundation for future monitoring programs measuring change in marine species diversity.

**Authors:**

Julie McInnes¹, Bruce Deagle², Andrea Polanowski³, Ben Raymond³, Sam Thalmann⁴, Rowan Trebilco², Barbara Wienecke³, Mary-Anne Lea¹

¹University of Tasmania, ²CSIRO, ³Australian Antarctic Division, ⁴Department of Primary Industries Parks Water and Environment

Methodological improvements in uncertain classification of individual-level demographic measurements: Improving reliability of inferences from citizen-science and field data

Next from 3rd World Seabird Conference

The effects of climate variability on seabirds breeding in the Tubbataha Reefs Natural Park, Philippines