#BOU2027 – Keynote abstracts
Avian disease ecology: combining avian ecology and OneHealth to understand and mitigate disease
6 – 8 April 2027
University of Nottingham, UK & Zoom & Bluesky
Alfred Newton Lecture
Bird feeding and disease: how we shape bird health—and how birds shape ours
Dana M. Hawley
Department of Biological Sciences, Virginia Tech, USA
Supplemental feeding is one of the most common and rewarding ways people around the world connect with wild birds. Although people often feed birds with the intention of helping them, feeding can also increase avian pathogen spread and contribute to declines to bird populations. Despite the enormous popularity of bird feeding and growing concerns about avian disease, we still have much to learn about how feeders affect avian health and which management practices help reduce disease risk. We also need to understand how people respond when they observe sick birds at their own feeders—and whether those responses motivate them to take actions such as cleaning feeders or temporarily stopping feeding. In this talk, I will examine the multiple ways that bird feeding can influence pathogen transmission, focusing on our ongoing work with Mycoplasma gallisepticum, a common bacterial pathogen of North American finches. I will also explore how feeding can inadvertently promote the evolution of more harmful pathogen strains by influencing the evolutionary trade-offs faced by pathogens. Finally, I will discuss insights from a collaborative socioecological data set collected by thousands of participatory scientists across the United States and Canada who feed birds. Our results suggest that people’s emotional responses and feeder management actions are closely tied to the health and abundance of the birds they observe at their feeders. Together with improved research on disease-mitigation strategies at feeders, understanding these human–bird connections can help promote feeding practices that protect avian health while maximizing the well-being benefits people derive from feeding birds.
Dana M. Hawley is a Professor in the Department of Biological Sciences at Virginia Tech, USA, where she has been on the faculty for 19 years. Her research program focuses on the ecology and evolution of infectious diseases in songbirds, and she is an internationally-recognized expert in studies at the intersection of animal behaviour and infectious disease. Dr. Hawley’s work spans diverse questions including how individual behaviour influences the risk of acquiring or spreading parasites, why some pathogens evolve to cause more harm to their hosts, and the role of supplemental feeding in pathogen transmission. Dr. Hawley was a co-editor of the 2021 book Infectious Disease Ecology of Wild Birds, published by Oxford University Press. Dr. Hawley is also a strong advocate for science communication to the broader public, and has published several articles in popular science outlets such as Scientific American and the Conversation.
Keynotes
High Pathogenicity Avian Influenza in seabirds: the benefits of integrative approaches
Thierry Boulinier
CNRS, France
Long lived wild species which breed in colonies have been particularly affected by the recent High Pathogenicity Avian Influenza (HP AI) panzootic. Such species may have evolved particular life histories and immune responses compared to more classically studied host species of avian influenza viruses. This outlines the importance of taking a new look at what is potentially driving the ecology and evolution of host-pathogen interactions insuch systems. Seabird species are important to study because many of their populations are threatened, but also because they represent original models in which individuals can be resampled over long time periods and in spatially structured set ups. From studies conducted at large seabird colonies in Europe and in the Southern Indian Ocean, I will present results highlighting the benefits of integrating approaches, from comparative immunology to phylogenetics and movement ecology. We notably found strong inter-year persistence antibody levels against HP AI virus in Northern Gannet (Morus bassanus) breeding adults using ELISA and seroneutralization assays, which has implications for interpreting serological surveys, but also heard immunity effects. We also found patterns of antibody levels against AI virus before and after the local emergence of HP AI in subantarctic seabird communities suggesting differential exposure and resistance. Combined with data on movements and virus phylogenetics, this has also implications for identifying transmission pathways at different scales. Finally, we explored the dynamics of antibody levels following field vaccination of young King Penguins (Aptenodytes patagonicus) against H5 HP AI protein. Overall, the results outline the benefits of integrative approaches to address questions of high basic and applied relevance in the context of the current HP AI panzootic.
Hidden hosts: uncovering hemoparasite infections in non-passerine birds
Érika M. Braga
Department of Parasitology, Universidade Federal de Minas Gerais, Brazil
Avian haemosporidians (Apicomplexa: Haemosporida) are the most widespread and extensively studied hemoparasites infecting birds, yet our understanding of their diversity and host associations remains strongly biased toward Passeriformes. This bias is largely driven by the greater accessibility of these birds in the wild, particularly through mist-net sampling, leaving many non-Passerine hosts comparatively unexplored. Here, we investigated haemosporidian infections in non-Passerine birds using an integrative approach combining molecular, morphological, and histopathological analyses. Birds admitted to a wildlife rehabilitation center provided a valuable opportunity to investigate hosts that are difficult to sample in the wild, leading to the identification of novel parasite lineages, new species, and previously unrecognized host associations. We also explored associations between haemosporidian infections and the birds’ physiological and clinical characteristics, including parasitemia, heterophil-to-lymphocyte ratio, ectoparasites, injuries, and concomitant infections. Our findings underscore the need to expand research beyond traditionally sampled hosts and highlight the potential of wildlife rehabilitation centers as strategic sites for uncovering hidden parasite–host interactions, thereby enhancing our understanding of avian haemosporidian diversity and ecology.
If we are serious about One Health, what does it take to keep birds healthy?
Ruth Cromie, OBE
Former WWT Head of Ecosystem Health and CMS COP-Appointed Councillor for Wildlife Health
There were once heady days when a conference on avian disease ecology might itself have seemed unusual. Those days are long gone. We now face urgent conservation challenges from disease threats capable of population-level impacts on bird species in multiple and diverse habitats.
With neither the time nor resources to tackle every emerging health threat individually, we need to work further ‘upstream’: understanding the determinants of health as well as the drivers of disease, addressing the conditions that allow disease threats to emerge. Ultimately, keeping birds healthy is more about people than it is about parasites. Yet addressing anthropogenic threats and human behaviours takes us well beyond the natural sciences, and there remain yawning gaps between scientific understanding and the policies and actions needed to protect health.
The panzootic of highly pathogenic avian influenza (HPAI) has provided us with a bitter gift. It has brought together the different health sectors and a recognition of (in words at least) the importance of resilient ecosystems and the value, to all, of healthy wild bird populations. This opportunity should not be missed.
The talk will explore these broader themes while also reflecting on what lessons we can learn from tackling specific health issues such as lead poisoning and HPAI. It is moving from simply identifying what needs to be done, to creating the partnerships, mechanisms and frameworks that enable it to happen. The central challenge is to turn our collective understanding into action: moving beyond responding to individual diseases towards creating the conditions in which birds and ecosystems, upon which we all depend, can thrive.
The hidden burden and consequences of infection in wild birds
Emma Cunningham
University of Edinburgh, UK
Infectious agents are fundamental components of wild bird populations, yet their prevalence, diversity and consequences are often difficult to quantify. These infections span a continuum from acute infection, often with rapid and sometimes catastrophic effects on survival, to chronic infections that may persist with little overt clinical signs but nevertheless impose substantial costs on host fitness. Understanding this continuum and it’s consequences therefore requires us to look beyond mortality and outward clinical signs to the often hidden burden of infection within populations. Long-term studies on seabird populations, for example have shown conventional techniques to quantify parasite burden may heavily underestimate the full extent of infection in populations. Novel approaches have revealed not only that infection may be far more widespread than previously thought, but that these hidden infections can have major consequences for key behaviours and life history traits including movement patterns, foraging patterns and breeding success. The recent outbreak of highly pathogenic avian influenza in seabirds provides a contrasting example of acute infection with substantial mortality over remarkably short timescales, with consequences extending from individuals to colonies and populations. However, surveillance of outwardly healthy parts of the population reveals a more complex and less visible epidemiological landscape with seabirds harbouring a diversity of viruses without obvious symptoms. This diversity is important not only because different viruses have different ecological and pathogenic characteristics, but because co-infection creates opportunities for genomic reassortment and a potential source of further future viral emergence. Together, these examples demonstrate that infection is not simply a cause of disease. Chronic and acute infections can shape survival, reproduction, behaviour, movement and population dynamics, while hidden pathogen diversity can influence the future trajectory of infectious disease. Understanding wild bird populations therefore requires understanding the infections they carry—even when those infections cannot be seen.
Trade-offs in transmission processes in natural populations
Josh Firth
University of Leeds & Oxford University, UK
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Finch in a pinch: effects of invasive parasites on Darwin’s finches in the Galápagos Islands
Sarah Knutie
University of Connecticut, USA
Over the past several decades, the Galápagos Islands of Ecuador have experienced a rise in ecotourism and residential human population size. This change in human activity has also coincided with the introduction of several invasive parasites, such as the avian vampire fly (Philornis downsi) that negatively affects endemic Darwin’s finches by exsanguinating nestlings in their nests. I will present our recent work showing that fly parasitism has a greater, negative effect on non-urban nestlings (~95% mortality) than urban nestlings (~50% mortality). Urban nests contain fewer flies than non-urban nests, which suggests that urban nestlings are more resistant to parasitism. Although urban nestlings express more innate immune genes (e.g. interferons) compared to their non-urban counterparts, this expression is a response to the invasive avian pox virus rather than flies. Instead, the difference in fly abundance is likely because adult female flies visit and lay their eggs more often in non-urban nests than urban nests. Urban nestlings are also more tolerant to flies because they can effectively recover red blood cells that are lost to the parasite. The ecological factor driving this tolerance in urban nestlings is unknown, but I will highlight experiments that have helped exclude potential candidates. Finally, I will present our past and future work on avian vampire fly management, since the fate of several Darwin’s finch species depends on our intervention.
Avian Malaria and their viruses in a changing world
Ravinder Sehgal
San Francisco State University, USA
Deforestation driven by the expansion of oil palm plantations is transforming tropical forests at an unprecedented rate, with profound consequences for biodiversity and the transmission of infectious diseases. Long-term studies of avian malaria parasites, their vectors, and wild bird communities in the tropical forests of Cameroon provide an opportunity to examine how land-use change alters vector-borne disease systems. Comparisons between intact forest and areas converted to oil palm plantations demonstrate that deforestation dramatically alters bird and mosquito communities and can reshape the prevalence, diversity, and transmission of avian malaria parasites. Recent comparisons with sites first sampled approximately 20 years ago provide an additional perspective on the long-term consequences of environmental change, revealing substantial shifts in parasite communities in disturbed habitats while comparatively intact forests have remained more stable.
An emerging dimension of malaria parasite biology adds another level of complexity to these interactions. Matryoshka RNA viruses (MaRNAVs) are recently discovered viruses associated with Plasmodium, Haemoproteus, and Leucocytozoon, the major groups of avian haemosporidian parasites. Recent studies of naturally infected birds in California have revealed these viral hyperparasites within avian malaria systems, raising fundamental questions about their potential effects on parasite fitness, transmission, virulence, and evolution.
Together, these findings reveal a nested and dynamic disease system in which environmental change acts across multiple biological scales: from landscapes and wildlife communities to vectors and parasites, and ultimately to the viruses associated with the parasites themselves. Understanding these interactions provides new perspectives on the ecology and evolution of infectious diseases in a rapidly changing world.
Scientific Programme Committee
Alice Risely | Chair | University of Salford, UK & BOU Meetings Committee
Daniela de Angeli Dutra | Bangor University, UK
Jenny Dunn | Keele University, UK
Jamie Dunning | University of Leeds, UK & BOU Engagement Committee
Stephen Vickers | Biomathematics and Statistics Scotland (BioSS), UK