United States

**Abstract:**

Investigating how individual animals balance their energy budgets and survive full annual cycles is important for understanding interannual demography and the subsequent viability of populations. Due to the challenges associated with investigating year-round energy budgets and energy landscapes, understanding how individuals balance their energetics and avoid bottlenecks throughout the year remains poorly understood. Whilst technological advancements are increasing our knowledge of animal energy expenditure, we developed an approach to investigate how other key components of animal energy budgets, namely energy gain and storage, varied in space and time. We developed a hierarchical Bayesian state-space model that used estimates of time-activity budgets, locations, and energy expenditure, derived from biologging data, to infer year-round time series of animal energy income and reserves. Our study system was a population of common guillemots Uria aalge breeding at a western North Sea colony. These seabirds manage their energy budgets by adjusting their behaviour and accumulating fat reserves. However, large-scale mortality events, where the proximate cause of death is starvation, following birds being in energy deficit over a sustained period, can still occur during severe weather conditions. We show that guillemot energy gain varies in both time and space. Our model was also able to account for seasonality in extrinsic drivers such as sea surface temperature and daylength, allowing us to identify times and locations of high energy gain. Estimates of guillemot body mass varied throughout the annual cycle and there was evidence that birds periodically experienced losses in mass, possibly due to energetic bottlenecks, leading to increased susceptibility to mortality. Birds also tended to be lighter towards the perimeter of their spatial distribution. We describe a framework that combines biologging data, conventional time-activity budget analysis, and Bayesian state-space modelling to identify times and locations of high energetic reward or energetic bottlenecks in a wild animal population. More broadly, this approach can be extended to address pure and applied scientific questions regarding the ecology, management and conservation of populations of wild, mobile animals that have previously been impossible to answer due to logistical complexities in collecting data across full annual cycles.

**Authors:**

Ruth Dunn¹, Jonathan Green¹, Francis Daunt², Sarah Wanless², Mike Harris², Jason Matthiopoulos³, Mark Newell², Maria Bogdanova², Cat Horswill⁴

¹University of Liverpool, ²UK Centre for Ecology &amp; Hydrology, ³University of Glasgow, ⁴ZSL Institute of Zoology

3rd World Seabird Conference

Modelling and mapping how common guillemots balance their energy budgets over a full annual cycle

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>

<iframe width="560" height="315" src="https://www.youtube.com/embed/rCc-s9eu6og" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

<iframe width="560" height="315" src="https://www.youtube.com/embed/JOLEP6uTMuc" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>



Join us for four days of science, networking and virtual engagement with delegates from around the world!

**Abstract:**

Investigating how individual animals balance their energy budgets and survive full annual cycles is important for understanding interannual demography and the subsequent viability of populations. Due to the challenges associated with investigating year-round energy budgets and energy landscapes, understanding how individuals balance their energetics and avoid bottlenecks throughout the year remains poorly understood. Whilst technological advancements are increasing our knowledge of animal energy expenditure, we developed an approach to investigate how other key components of animal energy budgets, namely energy gain and storage, varied in space and time. We developed a hierarchical Bayesian state-space model that used estimates of time-activity budgets, locations, and energy expenditure, derived from biologging data, to infer year-round time series of animal energy income and reserves. Our study system was a population of common guillemots Uria aalge breeding at a western North Sea colony. These seabirds manage their energy budgets by adjusting their behaviour and accumulating fat reserves. However, large-scale mortality events, where the proximate cause of death is starvation, following birds being in energy deficit over a sustained period, can still occur during severe weather conditions. We show that guillemot energy gain varies in both time and space. Our model was also able to account for seasonality in extrinsic drivers such as sea surface temperature and daylength, allowing us to identify times and locations of high energy gain. Estimates of guillemot body mass varied throughout the annual cycle and there was evidence that birds periodically experienced losses in mass, possibly due to energetic bottlenecks, leading to increased susceptibility to mortality. Birds also tended to be lighter towards the perimeter of their spatial distribution. We describe a framework that combines biologging data, conventional time-activity budget analysis, and Bayesian state-space modelling to identify times and locations of high energetic reward or energetic bottlenecks in a wild animal population. More broadly, this approach can be extended to address pure and applied scientific questions regarding the ecology, management and conservation of populations of wild, mobile animals that have previously been impossible to answer due to logistical complexities in collecting data across full annual cycles.

**Authors:**

Ruth Dunn¹, Jonathan Green¹, Francis Daunt², Sarah Wanless², Mike Harris², Jason Matthiopoulos³, Mark Newell², Maria Bogdanova², Cat Horswill⁴

¹University of Liverpool, ²UK Centre for Ecology & Hydrology, ³University of Glasgow, ⁴ZSL Institute of Zoology

technical paper

**Abstract:**

Since the 1970s, the oceans have buffered the increasing amount of heat as a result of increasing atmospheric temperatures. Since 2013, a large, anomalous patch of warm water has persisted around North America?s west coast and is believed to be the primary cause for thousands of seabird and marine mammal mortalities. While the mechanism(s) are not entirely understood, the cause of the deaths has largely been identified to be starvation. Short-tailed Shearwaters Ardenna tenuirostris (STSH) experienced significant mass mortality (?wreck?) events on their foraging grounds in the North Pacific Ocean. During June to August 2019, at least 9,000 STSH died. In September, STSH begin their ~11,000 km southward migration to their breeding grounds in southeast Australia. Widespread reports of late arrivals raised further concerns for this highly synchronous species. The numbers at colonies were substantially lower than previous years. We document the breeding success of two STSH colonies in southeast Tasmania, and compare the 2019/20 breeding population size with data from 2011.

**Authors:**

Jacqueline Glencross¹, Jennifer Lavers¹, Eric Woehler²

¹University of Tasmania, ²Birdlife Tasmania

Breeding success of Short-tailed Shearwaters Ardenna tenuirostris following large-scale oceanographic change

**Abstract:**

The expansion of marine protected areas in pelagic areas has been crucial to achieve sufficient protection of the oceans. However, there is still some controversy about whether these protected areas actually cover the vital areas for some species. We investigate the summer distribution of the critically endangered Balearic Shearwater and its overlap with the Special Protection Area for seabirds (SPA), using the Gulf of Cadiz as a case study. This area holds the SPA named Marine Area of Gulf of Cádiz, covering 2 314.2 km2. A dataset of nine years of vessel-based surveys between 2006-2017 was analysed, using Kernel Density Estimation to generate the core area polygons for each year. The area located off the Bay of Cádiz, southeast of the mouth of the Guadalquivir, has revealed as a very consistent key area for this species during summer. This area, covering 1 082 Km2, regularly hosted populations that exceeded the threshold for area of international importance (IBA criteria) for the species. The current SPA covers less than 40% of this new key area. The limitation in the number of years of monitoring and seasonal differences in the dataset used to establish the boundaries of the current protected area may be at the base of these discrepancies. This study emphasizes the importance of synthesizing and collecting long-term information to define marine protected areas and to assess their efficiency over the time. Furthermore, our study highlights the urgent need to expand this marine protected area to protect effectively this critically threatened species.

**Authors:**

Andres de la Cruz Muñoz¹, Gonzalo Muñoz Arroyo¹, Dario Delgado²

¹University of Cadiz, ²Private

How adequately are the critically endangered Balearic Shearwaters protected by the Special Protection Areas (SPAs) for seabirds? A case study in the Gulf of Cadiz.

**Abstract:**

Studies of seasonal migration within and between species help us to understand the drivers of this behaviour, why a diversity of strategies is observed and what might happen in the future under environmental change. Seabirds demonstrate the full range of non-breeding movement strategies from remaining fully resident to undertaking some of the longest recorded migrations. We investigated movement, behavioural time budgets and subsequent energetic costs during three winter non-breeding periods of a population of Australasian gannets (Morus serrator) breeding in southern Australia. We observed a novel strategy of facultative dispersal migration, not previously described in seabirds. In two years (2015 & 2016), gannets showed partial migration, similar to congeneric species, with some individuals travelling up to 2500 km while others remained resident. However in 2003, no individuals undertook a substantive migration and all remained close to their breeding colony throughout the winter. One consequence of this flexibility was an 8% increase in daily energy expenditure (DEE) at the population level in years with partial migration. This was driven by an increase in the time spent on water by migrating individuals, rather than an increase in the time spent in energetically costly flight. DEE for all strategies was greater during the winter than during the summer breeding period. We conclude that pressure for nesting space in their breeding colony, coupled with adequate locally available prey resources during winter means that for some individuals and in some years, migration is not advantageous or necessary. However the high DEE and observation of periodic partial migration suggests that in some years local resources are not enough to support the entire population, necessitating a dispersive migration in some individuals. Further work will investigate the nature of these localised drivers and whether this flexibility may provide resilience to environmental change.

**Authors:**

Jonathan Green¹, Norman Ratcliffe², Ashley Bunce³, John Arnould⁴

¹University of Liverpool, ²British Antarctic Survey, ³University of Queensland, ⁴Deakin University

Australasian gannets demonstrate population-level flexibility in migration strategy

**Abstract:**

Marine traffic has increased significantly since the turn of the century with associated amplification of noise fields having an important bearing on marine animals that utilise the same environment. The impacts of increased shipping traffic on seabirds is likely to become a major concern for seabirds that breed and forage close to busy maritime areas. The largest colony of the endangered African Penguin at St Croix Island is situated adjacent to one of the busiest marine traffic regions in South Africa. Marine traffic has increased significantly since 2016 when ship-to-ship bunkering activities commenced near the penguin colony. The breeding population of African Penguins here decreased by > 50 % since this time and we investigated if increased marine traffic, and associated marine noise, had any influence on this trend. To do this we compared temporal trends in location fixes of stationary and in-transit vessels in Algoa Bay, using Automatic Identification System data, to the number of penguin breeding pairs before and after significant change-points in vessel traffic volumes. The results are discussed considering the current potential for maritime influences on threatened seabird colonies and various approaches that can hopefully mitigate these threats.

**Authors:**

Alistair McInnes¹, Laetitia Vibert², Andrea Thiebault³, Isabelle Charrier³, Katta Ludynia⁴, Nicky Stander⁴, Tegan Carpenter-Kling¹, Lorien Pichegru²

¹BirdLife South Africa, ²Nelson Mandela University, ³University of Paris, ⁴SANCCOB

The impacts of marine traffic on a diving predator, the African Penguin

**Abstract:**

With increasing threats to seabirds from multiple anthropogenic impacts, there is a compelling need for local communities to support and engage in efforts to conserve many seabird populations. To engage communities meaningfully, their awareness and perceptions of species of conservation concern and conservation activities need to be understood. Réunion Island, Indian Ocean, is home to a diverse seabird community, including two endemic species of petrels, the Critically Endangered Mascarene petrel (Pseudobulweria aterrima) and the Endangered Barau's petrel (Pterodroma baraui). In this study, we assessed public knowledge of and attitudes towards the two endangered petrels and community-focused seabird conservation activities. We used two social surveys, one focused on recognition of Réunion seabirds and the long-term seabird rescue campaign on the island and the second on "Nuits Sans Lumiere," an annual month-long event to raise awareness of light impacts on seabirds. Ability to correctly identify species, endemic status and threats varied by species, with Barau's Petrel the best understood of the six focal species. In contrast, survey respondents were not as aware of the Critically Endangered Mascarene Petrel. Survey results indicate that impacts of light pollution on procellarid seabirds were generally well understood but that participation in the seabird rescue campaign is not widespread. Knowledge of and participation in "Nuits Sans Lumiere" varied by city, with Cilaos, the city closest to petrel breeding colonies, being the most engaged. The event was perceived as beneficial for the petrels and for reducing energy usage. These results will help guide future community outreach and policy-making efforts. Keywords : Sociological survey, Procellariidae, Rescue Campaigns, Nuits Sans Lumière, social representation.

**Authors:**

Marion Manoro¹, Peter Hodum², Marie Thiann-Bo Morel¹, Matthieu LE CORRE¹, Patrick Pinet³

¹University of Réunion Island, ²Oikonos Ecosystem Knowledge, ³Reunion National Park

Sociological analysis of seabirds rescue campaigns at Réunion Island

**Abstract:**

Little has been reported on moult in sulids, including gannets. The Cape Gannet Morus capensis is an endangered seabird endemic to southern Africa. We describe the timing, duration, symmetry and sequence of flight feather moult in Cape Gannets from two breeding colonies and assess whether moult can be used as an index of condition. Using the Underhill-Zucchini model, we estimate moult parameters based on the proportion of feather mass grown. Adult Cape Gannets began primary moult at the beginning of January (2-3 January ± 28 days SD) at both colonies. Primary moult is protracted, with multiple active centres (mean ± SD 1.8 ± 0.8, range 1-4) and 2.0 ± 0.9 feathers growing at the same time (range 1-5). Primary moult is suspended by early June at Malgas Island (estimated duration of moult ± SE, 153.9 ± 4.1 days) and late June at Lambert's Bay (176.5 ± 5.5 days). Secondary moult commenced in late January and proceeded from two nodal points. Despite more secondaries (3.3 ± 1.9, range 1-8) being grown simultaneously than primaries, 8% of birds were still moulting secondaries at the start of the breeding season. However, it was not certain that these individuals were breeding. Tail moult also overlapped with that of the primaries, with multiple active centres (2.7 ± 1.2, 1-6) and 2.9 ± 1.3 feathers growing at the same time (range 1-8). Almost all primary (98%) and secondary moult (97%) was symmetrical, but there was little symmetry in tail moult (54%). Rectrix symmetry tended to be greater among gannets at Malgas Island (T1: 58%; T2-T6: 67-73%) than at Lambert's Bay (T1: 50%; T2-T6: 55-66%). Differences in moult duration and perhaps asymmetry between locations may be linked to foraging conditions, given that Lambert's Bay gannets are thought to be under greater food stress than Malgas birds.

**Authors:**

Oluwadunsin Adekola¹, Rob Crawford², Bruce Dyer², Azwianewi Makhado², Leshia Upfold², Peter Ryan¹

¹University of Cape Town, ²Department of Forestry, Fisheries and Environment

Timing, duration and symmetry of moult in the Cape Gannet Morus capensis

**Abstract:**

Cory's Shearwater (Calonectris borealis) juveniles, like most tubenose seabirds, are negatively affected by light pollution during fledging. Urban artificial lights attract and disorientate juveniles that fall to the ground in massive numbers. Since 2001, a citizen-science rescue campaign organized by DRAM, Azores Government, has allowed the rescue and release to sea of over 38.000 juveniles throughout the Azores archipelago. The campaign is well established with high success rates, releasing around 90% of collected juveniles. The fate of rescued birds and their recruitment into the breeding population, however, are unknown. The species' nocturnal habits, delayed recruitment or inaccessible colonies prevent an efficient recapture of returning individuals. Only 13 out of 9000 fledglings ringed and measured during the rescue campaigns have been recovered (6 alive, 7 dead). Here we apply an alternative method to assess campaign effectiveness by using biometric data collected during ringing, to estimate the potential post-release survival of rescued juveniles. Mass at fledging has been linked with juvenile survival (minimum 85% of adult average mass). Potential survival after release was estimated using the corresponding threshold of 714g (85% of average adult mass in the Azores). Results show that 65% of released juveniles were above the threshold. These preliminary results corroborate the campaign as a mitigation tool for light-induced fledgling mortality, with high proportions of rescued individuals and a high potential survival at release. Of the recaptured individuals (confirmed survival) 75% were above threshold at fledging, however more recaptures are needed to accurately estimate survival mass threshold. Overall fledgling condition deteriorates throughout the rescue campaign, with the latest fledglings being lightest. Correctly assessing survival thresholds will help to improve campaign design and effectiveness. Future assessments will include juvenile survival rates at-sea and conditioning environmental factors that can further reduce survival.

**Authors:**

Elizabeth Atchoi¹, Joël Bried¹, Sofia Garcia², Airam Rodríguez³

¹Okeanos-UAç, ²DRAM - Regional Directorate for Sea Affairs, ³CSIC - Department of Evolutionary Ecology, Estación Biológica de Doñana / GOHNIC

Effectiveness of a 20-year seabird rescue citizen-science campaign: estimating post-release survival

**Abstract:**

Gadfly petrels (Pterodroma genus) are pelagic seabirds of increasing conservation concern most of which are endemic to oceanic islands. In the North Atlantic, the Pterodroma cahow recovered from near-extinction due to the implementation of a recovery plan initiated in the 60s. The remnant population of 18 pairs has steadily increased to 131 pairs in 2019 but breeding failure due to decreased egg hatchability has increased over the last decade (25%-44%). Similarly, to promote population recovery reducing disturbance, fundamental aspects of P. Cahow behavioural-ecology have remained little understood. To fill this gap of knowledge, in 2019, we investigated, for the first time, the at-sea distribution, trophic ecology and exposure to contaminants of adult individuals. GPS-tracked birds (n=28) spent 56.2% of their foraging time in areas beyond national jurisdiction followed by 34.8% in the EEZ of the Bermudas and, 4.5% in waters of both Canada and of the United States. There were no significant differences in trip extension between sexes or seasons but, the amount of time spent at-sea tended to be higher during incubation than during chick-rearing. The areas used for foraging in both seasons did not coincide, and consequently deferred in terms of oceanographic conditions i.e., bathymetry and SST. Moreover, birds isotopic niche (blood δ15N and δ13C) resulted completely segregated between seasons with individuals feeding at higher trophic positions during chick-rearing. PCBs were the most ubiquitous persistent organic pollutant in terms of detection rate although mean concentration in blood was moderately low (7.87 ng/g w.w). Total PCBs and OCPs concentrations decreased with increasing bird body mass but were unrelated to δ15N or δ13C levels. Concurrently, egg hatching probability was negatively related to PCBs and OCPs concentrations suggesting potential adverse effects on reproduction. Totally, we provided new information with important implications for the management and conservation of a globally endangered species

**Authors:**

Letizia Campioni¹, Jeremy Madeiros², José Pedro Granadeiro³, Bernat Oró-Nolla⁴, Silvia Lacorte⁴, Ilaria Marengo⁵, Marcello D'Amico⁶, Monica Silva⁷

¹ISPA-Istituto Universitario, ²Ministry of the Environment, PO Box FL588, Flatts, FL BX, Bermuda, ³Faculdade de Ciências da Universidade de Lisboa, CESAM, ⁴Institute of Environmental Assessment and Water Research (IDAEA-CSIC), ⁵InnovPlantProtect, ⁶Doñana Biological Station (CSIC), ⁷Faculdade de Ciências, Universidade de Lisboa

Beyond safe land: revealing the oceanic distribution and exposure to anthropogenic contaminants of the globally endangered Bermuda petrel

**Abstract:**

I carried out a survey using a semi-structured questionnaire, in order to evaluate the knowledge, perceptions and attitudes of local people towards seabird conservation. The present study is the first preliminary attempt in the Indian subcontinent to infer the attitudes of local people towards seabirds. I interviewed a total number of 800 people from Kavaratti Island, the nearest inhabited island, located 24 km from Pitti. Pitti (10°4631.8ʺN, 72°323.4ʺE) is a small triangular-shaped coral island with an area of 0.0121 km2. I assessed the local people support for seabird conservation by identifying and evaluating the drivers of seabird egg collection, and the level of dependence on seabird eggs. 576 (72%) survey participants acknowledged their involvement either in harvesting or trade of seabird eggs. The majority of respondents (783, 98%) had knowledge of seabirds and had observed seabirds in their natural habitat. Only 3% of the respondents told that Pitti is regularly monitored by the authorities. 319 (40%) participants were either directly or indirectly involved in egg harvesting, and hence are less likely to support seabird conservation. A significant proportion (264, 33%) of the respondents were neutral in their support for seabird conservation. The present sociological survey indicates that the dependency of local people on seabird eggs will likely reduce their support for conservation. Hence, unregulated egg harvesting in a small breeding colony such as Pitti would drive the seabird population to their extinction.

**Authors:**

Ravichandra Mondreti¹

¹Independent Researcher & Consultant

Knowledge, Perceptions and Attitudes of local people towards seabird conservation: case study of Pitti Island, Lakshadweep, India

**Abstract:**

Common murres (Uria aalge) are expected to buffer activity budgets during poor conditions to compensate for low prey availability. However during a marine heatwave (2014-16) in the eastern North Pacific, we found that common murres nesting at Yaquina Head, Oregon, USA had near zero reproductive success (2015-17). Breeding success during this time was compounded by top down pressure from avian predators, primarily bald eagles (Haliaeetus leucocephalus), and while disturbance rates were highest in 2016 (0.495/hr), rates were slightly lower during the other heatwave years (0.29/hr) than preceding (2011-2013, 0.37/hr), when reproductive success was 0.41±0.06. Murres showed multiple signs of prey limitation during heatwave years. Birds caught at-sea near the colony and fitted with Argos-PTTs (2015-2016, n=15) typically foraged 174 km north at the mouth of the Columbia River. Daytime dives and central place foraging trips were notably longer in duration in 2015 than 2013. Feeding delivery rates during heatwave conditions in 2016 were on average the lowest in our time series ~0.15/hr (1999-2002, 2010-present). Fish length was not notably different from average in 2016, thus it appears murres did not compensate by increasing the size of delivered. In assessing heatwave impact, colony structure was also important, as a small subset of birds in nesting locations protected from eagle disturbance hatched chicks, at reduced rates, during peak heatwave years. The effects of the heatwave persisted into 2017, but in 2018 and 2019 reproductive success was high despite the continued occurrences of bald eagle disturbances. This suggests that predation can impede reproductive effort when prey availability was poor, potentially benefiting individuals by preventing investment in breeding, with reduced effect as foraging conditions improve. Our results indicate that murre reproductive success may be more stochastic as marine heatwaves become more common and the impact of these events may be exacerbated by predation at colonies.

**Authors:**

Jessica Porquez¹, Rachael Orben¹, Jane Dolliver¹, Stephanie Loredo¹, Ana Medina Roman¹, Donald Lyons², Robert Suryan³

¹Oregon State University, Hatfield Marine Science Center, ²National Audubon Society, ³NOAA Alaska Fisheries Science Center

Modelling and mapping how common guillemots balance their energy budgets over a full annual cycle

Downloads

Next from 3rd World Seabird Conference

Breeding success of Short-tailed Shearwaters Ardenna tenuirostris following large-scale oceanographic change

Similar lecture

Partner intrinsic characteristics influence foraging trip duration, but not parental care coordination in wandering albatrosses (Diomedea exulans)

Stay up to date with the latest Underline news!

PRESENTATIONS

CONFERENCES

COMPANY

RESOURCES

Modelling and mapping how common guillemots balance their energy budgets over a full annual cycle

.css-70qvj9{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;}Downloads

Next from 3rd World Seabird Conference

Breeding success of Short-tailed Shearwaters Ardenna tenuirostris following large-scale oceanographic change

Similar lecture

Partner intrinsic characteristics influence foraging trip duration, but not parental care coordination in wandering albatrosses (Diomedea exulans)

Stay up to date with the latest Underline news!

PRESENTATIONS

CONFERENCES

COMPANY

RESOURCES

Downloads