United States

**Abstract:**

Extinction of species and population declines are occurring globally as a consequence of human activities, including the occurrence of urbanization processes transforming the structure of natural habitats and exposing organisms to novel environmental challenges. That is the current scenario in the northern coasts of Argentina, as well as Uruguay and Southern Brazil, regularly used as winter quarters by the Olrog&#39;s gull (Larus atlanticus). This regionally threatened species was formerly known to be specialized in crabs but now to have incorporated a range of anthropogenic items in its diet. As part of an ongoing long-term study on the foraging ecology and health status of the Olrog&#39;s gull we investigated the impact of urbanization on the body condition of free-living individuals, measuring a range of blood parameters as indicators of body condition. Eighty-two gulls (46 juveniles and 36 adults) were captured at two sites with radically different levels of urbanization. Body weight, and levels of hematocrit, red and white blood cells, mean cell volume, heterophils, lymphocytes, eosinophils, monocytes, basophils, heterophils-lymphocytes ratio, glucose, uric acid, total protein, cholesterol, and triglyceride were determined. Most of parameters didn&#39;t show significant differences between the two populations. However, independently of sex and age, individuals from areas with low urbanization showed higher values of uric acid (1052.53±452.35 µmol/l), and lower levels of cholesterol (6.47±1.76 mmol/l) than individuals from highly impacted areas (455.08±305.69 µmol/l and 8.35±3.07 mmol/l, respectively). Adults from areas with low urbanization showed lower values of hematocrit than adults from impacted areas (39.14±7.47% and 44.00±4.68%, respectively). These differences in blood parameters could be considered as proxy indicators of health condition in Olrog&#39;s gulls exposed to urbanization in winter quarters. Further studies should focus on the effect of individual condition on the species recruitment and breeding success, taking into account the endemism, reduced population size and fragile conservation status of the species.

**Authors:**

GERMAN GARCIA¹, Melina Castano¹, Tomás Córdoba¹, Jesica Paz¹, Francisco Zumpano¹, Marco Favero¹

¹Instituto de Investigaciones Marinas y Costeras (UNMdP-CONICET)

3rd World Seabird Conference

Effect of urbanization on the individual condition of the regionally threatened Olrog´ gull

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:**

Extinction of species and population declines are occurring globally as a consequence of human activities, including the occurrence of urbanization processes transforming the structure of natural habitats and exposing organisms to novel environmental challenges. That is the current scenario in the northern coasts of Argentina, as well as Uruguay and Southern Brazil, regularly used as winter quarters by the Olrog's gull (Larus atlanticus). This regionally threatened species was formerly known to be specialized in crabs but now to have incorporated a range of anthropogenic items in its diet. As part of an ongoing long-term study on the foraging ecology and health status of the Olrog's gull we investigated the impact of urbanization on the body condition of free-living individuals, measuring a range of blood parameters as indicators of body condition. Eighty-two gulls (46 juveniles and 36 adults) were captured at two sites with radically different levels of urbanization. Body weight, and levels of hematocrit, red and white blood cells, mean cell volume, heterophils, lymphocytes, eosinophils, monocytes, basophils, heterophils-lymphocytes ratio, glucose, uric acid, total protein, cholesterol, and triglyceride were determined. Most of parameters didn't show significant differences between the two populations. However, independently of sex and age, individuals from areas with low urbanization showed higher values of uric acid (1052.53±452.35 µmol/l), and lower levels of cholesterol (6.47±1.76 mmol/l) than individuals from highly impacted areas (455.08±305.69 µmol/l and 8.35±3.07 mmol/l, respectively). Adults from areas with low urbanization showed lower values of hematocrit than adults from impacted areas (39.14±7.47% and 44.00±4.68%, respectively). These differences in blood parameters could be considered as proxy indicators of health condition in Olrog's gulls exposed to urbanization in winter quarters. Further studies should focus on the effect of individual condition on the species recruitment and breeding success, taking into account the endemism, reduced population size and fragile conservation status of the species.

**Authors:**

GERMAN GARCIA¹, Melina Castano¹, Tomás Córdoba¹, Jesica Paz¹, Francisco Zumpano¹, Marco Favero¹

¹Instituto de Investigaciones Marinas y Costeras (UNMdP-CONICET)

poster

**Abstract:**

Population levels, habitat use, and concentrations of heavy metal have been examined in Barnegat Bay since 1976. Colony sites were monitored several times/year during this period. The number of nesting pairs of Common Terns, Black Skimmers, Laughing Gulls, and Herring Gulls decreased significantly. Similarly, the number of nesting colonies of terns and skimmers decreased, although reproductive success did not decrease as rapidly as did the number of nesting pairs of terns and skimmers. Loss of nesting colonies resulted in decreases in the number of nesting pairs, as suitable habitat in the bay for terns and skimmers was limited. Great Black-backed Gulls have increased markedly, partly because they are expanding southward along the Atlantic coast, and they are significantly larger than the other species, allowing them to outcompete other smaller species of gulls. Laughing Gulls have also declined, but their declines were mainly due to control (e.g. shooting) of them at nearby Kenney airport. However, even when the shooting ceased, their numbers continued to decline, largely because of competition with Herring Gulls for nesting sites on the marshes. Similarly, Great Egrets have increased as nesting birds in Barnegat Bay, while Snowy Egrets and others egrets and night-herons have declined. The most notable change in Barnegat Bay is a loss of nesting islands, and degradation of some of the remaining habitat, due mainly to sea level rise. Sea level rise is greater in the northeastern Atlantic coast than in other parts of the world (due to both rising sea level and subsidence). Many islands have disappeared or become sub-optimal for nesting. Except for mercury, most metals have declined over this same time period, indicating they are not likely to contribute to the overall declines. Over the years this research has been funded by the US Environmental Protection Agency (Estuaries Program), NJ Department of Environmental Protection (Endangered and Nongame Species Project), Trust for Public Lands, Rutgers University, and the Tiko Fund.

**Authors:**

Joanna Burger¹, Michael Gochfeld¹

¹Rutgers University

Effects of Sea Level Rise on Nesting Populations of Colonial Birds in Barnegat Bay: 1976 to 2020

**Abstract:**

Marine conservation requires regulation of potentially harmful practices so that they do not adversely impact species, communities and ecosystems. While many approaches to identify sites critical to the conservation of species are specific to individual taxa, an overarching framework - yet to be applied to seabirds - has recently been developed which allows for the identification of sites critical to the persistence of all biodiversity; the Key Biodiversity Areas (KBAs) framework. These objectively defined sites will allow us to identify locations where conservation action is most critical. Furthermore, they play a critical role toward meeting the 2020 Aichi Biodiversity Targets and the 2030 Agenda for the Sustainable Development, as the coverage of KBAs by protected areas is already an indicator of these global goals. Utilising tracking datasets spanning 1991-2015, and published estimates of colony locations and abundances, we present a multi-taxa approach to identify KBA sites for species suited to site-based conservation measures. We apply this approach to albatrosses, large petrels, penguins and seals which breed at South Georgia and the South Sandwich Islands, and Antarctica. We utilise methodologies applicable to numerous seabird species: the use of tracking data to identify critical at-sea sites, and a modified foraging radius approach incorporating a density decay function in boundary delineation from colonies. As the world looks to expand economic development opportunities in the marine environment, we showcase how the KBA framework can be used to inform conservation action for top marine predators, inform decision makers about management measures such as time-area closures, research and monitoring priorities, and help the delineation of Marine Protected or Marine Managed Areas. Our approach has broad applicability to the development of future projects investigating species distributions and for the retrospective analysis of animal tracking data.

**Authors:**

Jonathan Handley¹, Elizabeth Pearmain¹, Steffen Oppel², Ana Carneiro¹, Carolina Hazin¹, Richard Phillips³, Norman Ratcliffe³, Iain Staniland³, Thomas Clay⁴, Victoria Warwick-Evans³, Phil Trathan³, Maria Dias¹

¹BirdLife International, ²Royal Society for the Protection of Birds, ³British Antarctic Survey, ⁴University of Liverpool

A step toward saving the seabirds: Marine spatial planning informed through the application of the Key Biodiversity Area framework to seabird distribution data

**Abstract:**

With the earth's increasing surface temperature, the augmentation of extreme climatic events such as tropical cyclones and storms has been predicted. However, studies on the impact of such events on island and remote atoll ecosystems are still lacking in literature. Farquhar Atoll (Seychelles) was hit by the strongest tropical cyclone ever recorded in the Western Indian Ocean Region (Cyclone Fantala) in April 2016. We assessed the impact of the Cyclone Fantala on the Farquhar ecosystem, focusing in particular on vegetation and seabirds. The data collection on vegetation was carried out immediately after and one year after the climatic event took place giving the opportunity of investigating both resistance and resilience of the different taxa included in this study. We assessed in total 25ha of terrestrial habitat. Overall, we found that the destruction and regeneration (one year after the cyclone) of the indigenous tree/shrub species were respectively lower and higher than non-native tree/shrub species, making them more resistant and resilient. The number of breeding seabirds' and their habitat selection pre and post cyclone were also assessed and we found that the Red-footed Booby population doubled the year after the cyclone and since then had a highly positive trend. The individuals also swapped nesting sites from Casuarina trees (non-native) to native shrubs. The number of pairs of the other seabirds breeding on the island remained stable. We can conclude that atolls left in their natural state are more resistant and resilient than deeply modified ones. Such information is fundamental to inform atoll ecosystem management in Seychelles and elsewhere in order to minimise the impact of destructive climatic events on target species.

**Authors:**

Licia Calabrese¹, Aurelie Duhec¹, Thomas Collier¹, Richard Jeanne¹

¹Island Conservation Society

Resistance and resilience of vegetation and seabird community in a tropical atoll impacted by a strong cyclone

**Abstract:**

Many seabird species travel large distances throughout their annual cycles, occurring in multiple jurisdictions. Many of these species are also threatened or in decline, being exposed to marine threats such as bycatch in fishing gear, overfishing, light pollution and infrastructure development at sea. Therefore, their effective conservation depends often on the concerted conservation effort of several countries. In Europe, seabird species are protected under the Nature's directives, and several important foraging sites for breeding species have been identified (e.g., through the IBA network) and protected (as SPA or other MPA) over the last decade. However, Europe also hosts many highly migratory and mobile species, which spend a considerable amount of their time in non-European waters. Here we analysed the network of marine IBAs for 32 migratory species of seabirds breeding in Europe and quantified the extent to which these areas are under some form of protection. We found that 7% of the marine IBAs identified for migratory European seabird populations are outside Europe, even though some of these species perform long distance movements and spend a large percentage of their annual cycle in African and American waters, or in areas beyond national jurisdiction. Most of these sites are triggered by: Audouin's gull Larus audouinii, Scopoli's shearwater Calonectris diomedea, Cory's shearwater Calonectris borealis, Zino's petrel Pterodroma madeira and Desertas Petrel Pterodroma deserta. The extent to which marine IBAs for migratory European seabirds in waters outside Europe are covered by MPAs is considerably lower (less than 30%, on average), than within European Exclusive Economic Zones (more than 75%). None of the sites identified for the two threatened Pterodroma species outside of Europe is currently under any level of protection. This study highlights the need to identify and protect a relevant network of marine sites that covers the different stages of the annual cycle of migratory seabirds, most of which are impacted by threats occurring at sea, and put more effort on identifying mIBAs also during their non-breeding period. Despite strong EU environmental legislation, the effective management of sites within European jurisdiction is still incomplete and is also insufficient to adequately safeguard migratory seabirds without corresponding protection within the EEZs of third countries and in the high seas where many of the threats are encountered.

**Authors:**

Antonio Vulcano¹, Daniel Mitchell², Maria Peixe Dias¹

¹BirdLife International, ²Stichting Birdlife Europe

Are world marine IBAs/MPAs effectively covering important sites for migratory seabirds? A case study with European breeding species

**Abstract:**

Individuals often vary widely in their movement behaviour. Sometimes, this variation can be explained by plastic adjustments to prevailing conditions, but a growing evidence base shows that individuals can also be highly consistent in how they utilize space, once environmental conditions have been controlled for. The causes of this among-individual variation remain largely unknown, and in particular, the extent to which genetic variation contributes to total phenotypic variation in movement behaviour has seldom been examined in a wild population; despite being necessary for understanding the evolutionary potential of potentials. In this study, we combine a large-scale longitudinal tracking data set with an extensive social pedigree to estimate heritability in a suite of foraging-related movement behaviours (e.g. trip duration, etc) - for an ocean sentinel species, the wandering albatross Diomedea exulans. We focus on foraging trips undertaken during the incubation period, when adult birds face strong constraints brought about by the competing needs of self-maintenance, chick feeding, and partner relief. Our preliminary results suggest repeatability in foraging-related movement behaviours. Power analyses revealed the potential to detect heritability in foraging traits. However, based on our current assessment, heritability in mean trait values appear very low (< 0.1), suggesting that other mechanisms are likely to explain individual variation in foraging behaviour.

**Authors:**

Jack Thorley¹, Joanie Van de Walle², Stephanie Jenouvrier², Henri Weimerskirch³, Samantha Patrick¹

¹University of Liverpool, ²Woods Hole Oceanographic Institute, ³CNRS - Université de la Rochelle

The heritability of foraging behaviour in wandering albatrosses

**Abstract:**

The knowledge of the distribution of seabirds is one of the most important factors in order to establish adequate protection and conservation measures. Seabirds are highly mobile animals making necessary to determine their distribution areas by relating environmental and oceanographic variables to the occurrence of seabirds. In most studies, Chlorophyll Concentration or Sea Surface Temperature are the most important environmental factors that determine its distribution. However, obtaining data at the local level and more directly related to the ecology of the birds, we could determinate if the real variable determining the distribution of seabirds is the predator-prey relationship. In this study, we aim to answer the question about what factors really determine the distribution of seabirds at a regional level obtaining direct information between the occurrence of seabirds and the prey they feed on. We analyse data from oceanographic campaigns to evaluate the fishing stock of the Gulf of Cádiz for 11 years, obtaining information on the distribution of fish species in their different stages (egg, larval, early-juvenile, adult), which are prey and food base for two endangered and protected species of seabirds: Balearic Shearwater and European Storm Petrel.

**Authors:**

Andres de la Cruz Muñoz¹, Gonzalo Muñoz Arroyo¹

¹University of Cadiz

Drivers for spatial modelling of a critically endangered seabird on a dynamic ocean area: Balearic shearwaters are non-vegetarian

**Abstract:**

Penguins are pursuit divers that feed mainly on fish, crustacivores, and squids. Differences in diet and other ecological traits implied in foraging habits might leave a correlate in the wing apparatus morphology. Ecological traits such as diving depths, foraging distance from the coast as well as prey composition are used to explore how morphology relates to foraging habits. A morphometric geometric approach is used to quantitatively address these morphological differences in the wing apparatus of all extant penguins. Results show that shape variation among penguins with different diets is significant and strong; groups are well separated with the greatest differences found between piscivorous and crustacivorous penguins. Dive depth has a moderate covariation with morphology and a strong correspondence with wing area. It is proposed that swimming styles correlate with specific traits of the morphoanatomy of wing and pectoral girdle skeleton and muscles.

**Authors:**

Nadia Haidr¹

¹Consejo Nacional de Ciencia y Técnica

Ecomorphology of the diving apparatus of penguins

**Abstract:**

Seabirds are very important links between the ocean and terrestrial ecosystems in the Arctic. They feed on marine resources over the pelagic zone while breed on land, often in huge colonies. Around the colonies, seabirds deposit substantial amounts of faeces which are extremely rich in nutrients locally crucial for tundra. Nonetheless, ornithogenic nutrients not incorporated into the terrestrial ecosystem can return to the sea, concentrate within the relatively small coastal area immediately adjacent to a colony, and constitute a locally important resource for marine producers and subsequent consumers there. Although this phenomenon has potentially great importance for the marine coastal food webs, it is still very poorly recognised. Here we present results of three-year studies of shallow water benthic communities functioning beneath a large guillemot and kittiwake colony in Isfjorden, west Spitsbergen. With the help of SCUBA we could explore and precisely sample the shallowest, down to ca. 20 m, coastal zone inaccessible with larger ships. The isotopic data obtained, i.e. increased δ15N of suspended and sedimentary particulate organic matter, as well as predatory/scavenging whelks and hermit crabs from the colony area, allow assuming that ornithogenic nutrients which returned to sea and concentrated in the vicinity of a seabird colony were used by phytoplankton first, and then entered the bottom food chains through pelagic-benthic coupling. Nonetheless, analysis of series of the seabed photographs taken along distance from the shore (the colony) towards the open sea showed that local environmental conditions, primarily depth and seabed topography clearly modified the seabird impact.

**Authors:**

Katarzyna Zmudczynska-Skarbek¹, Piotr Balazy², Piotr Kuklinski¹

¹University of Gdansk, ²Polish Academy of Sciences

Diversity of shallow water benthic communities below seabird colonies at Spitsbergen, High Arctic

**Abstract:**

In the UK, seabird populations are typically monitored during the breeding season when most species aggregate at colonies and accurate, cost-effective, surveillance can take place. Most seabird species, however, spend much of their lives at sea and a large proportion of the total population comprises immature birds or non-breeding adults which cannot be monitored using land-based surveys. Monitoring seabirds at sea is, therefore, essential to fully understand their population status, to identify trend drivers and to ensure appropriate and timely mitigation of them. At sea monitoring is usually delivered using boats or aircraft and, consequently, tends to be both expensive and logistically challenging. Regular at sea monitoring programmes are therefore rare. In 2018, JNCC began developing the Volunteer Seabirds at Sea (VSAS) programme and, in collaboration with CalMac Ferries and their Marine Awareness Programme, completed an inaugural survey season in 2019. The VSAS programme trains volunteer surveyors to collect high quality seabirds at sea data from ferries using the standard European Seabirds at Sea method. Data are captured and validated in real-time using rugged waterproof tablets with a bespoke application. This has removed the considerable input and validation time required for more traditional paper-based data capture systems. VSAS has demonstrated that citizen science schemes can be developed to provide a low-cost solution for the collection of high-quality seabirds at sea data.

**Authors:**

Tim Dunn¹, Mark Lewis¹, Danni Thompson¹

¹JNCC

Development and delivery of a citizen science seabirds at sea monitoring programme

**Abstract:**

Marine ecosystems worldwide are changing rapidly, and most marine systems lack well-developed biological indices. In the Gulf of Maine, rapid warming has coincided with major changes to breeding populations of seabirds, especially the Arctic (Sterna paradisaea) and Common Tern (S. hirundo). To investigate their potential as bioindicators, we examined trends in chick diets and reproductive measures in relation to bottom-up and top-down forcing. We used structural equation modeling, cluster analysis, and link tree analysis to investigate data from six (Arctic) and ten (Common) colonies, between 1991-2017. Both species showed major changes to their diets over time, coinciding with clear regime shifts in oceanographic properties and plankton communities. Arctic Terns fed chicks white hake (Urophycis tenuis) and Atlantic herring (Clupea harengus) in the 1990s, whereas Common Terns relied primarily on herring and sand lance (Ammodytes spp.). Between 2002-2008, salinity and temperatures decreased and preferred prey became less common alongside reduced tern reproductive success; small copepod Centropages typicus also declined. From 2010 onwards, temperatures increased and promoted species more tolerant of warm water; herring declined and was replaced by other taxa in tern diets. Arctic Terns consumed more white hake, while Common Terns integrated more gadoids and rarely seen taxa into their diets, each improving their reproduction from the previous decade. Lobster landings and herring price correlated with the Atlantic Multidecadal Oscillation, and worked as a combined index for stress of large gulls; predation by gulls on tern eggs increased following warming and the decline of the herring fishery. These relationships illustrate the interconnectedness of this ecosystem, where herring and its productivity are strongly affected by top-down and bottom-up forcing, and have cascading effects on gulls and terns. Both tern species have potential as bioindicators, especially using diet data associated with specific ecosystem states. Top-down forcing reduces the indicator potential of most reproductive data except asymptotic mass of chicks.

**Authors:**

Lauren Scopel¹, Antony Diamond¹, Kevin Friedland², Stephen Kress³, Paula Shannon⁴, Linda Welch⁵, Sara Williams⁵

¹University of New Brunswick, ²Northeast Fisheries Science Center, ³Cornell University, ⁴National Audubon Society Seabird Institute, ⁵US Fish and Wildlife Service

Effect of urbanization on the individual condition of the regionally threatened Olrog´ gull

Next from 3rd World Seabird Conference

Effects of Sea Level Rise on Nesting Populations of Colonial Birds in Barnegat Bay: 1976 to 2020

Similar lecture

Health status assessed by physiological parameters and pathogen tests in kelp gulls (Larus dominicanus) feeding on an urban sanitary landfill