UMD’s Jennifer Mullinax Co-authored a Wildlife Monograph Synthesizing What’s Known and Offering Guidance to Better Understand H5N1 in Wild Birds.
USDA capturing wild birds in 2006 to monitor for Avian Influenza. Today's strains are much more pathogenic and affect many more species.
Image Credit: U.S. Department of Agriculture
University of Maryland wildlife ecologist Jennifer Mullinax has co-authored an invited Wildlife Monograph that synthesizes decades of research to present a comprehensive picture of what scientists know, and do not yet know, about highly pathogenic avian influenza (HPAI) in wild birds.
Wildlife Monographs are stand-alone scholarly works published by the Wildlife Society that serve as authoritative resources for scientists, managers, conservationists, and other wildlife practitioners, aligning the most up-to-date research with contemporary conservation and management issues.
The monograph, Feathers and Flu: Identifying Data Gaps in Avian Influenza Host Dynamics to Prioritize Wildlife Conservation, was published May 15, 2026.
"Effective management of highly pathogenic avian influenza, or HPAI, in wild birds requires translating complex ecological information into actionable guidance," said Jennifer Mullinax, who is an associate professor in the Department of Environmental Science and Technology at UMD and the corresponding author on the monograph. "This monograph aims to help scientists, managers, and policymakers better understand HPAI, emphasizing the uniqueness of this virus, all we still do not know, and management options that seem effective."
Understanding the spread of infectious diseases in migratory birds is especially difficult because there are so many variables in play, including multiple species traveling the same or similar routes, sometimes together, across long distances through varying landscapes and ecosystems, all affected by different human influences and management practices. But for many decades, the need to control low pathogenic avian influenza was less critical than it is today because it was limited in scope and severity and well managed in the poultry industry.
But that changed with the arrival of the H5N1 strain of avian flu in the U.S. in 2020. The highly pathogenic virus emerged in Asia in 1996 and has had devastating impacts on both wild birds and domestic poultry as it has spread around the world. Today's H5N1 is particularly concerning because it infects a wider range of bird species as well as non-avian species such as marine mammals, while also spreading more easily and causing more severe disease than previous strains. As the virus adapts rapidly to new hosts and ecological systems, understanding how it spreads and which species are most at risk has become increasingly urgent.
The monograph presents a research-based, holistic picture of infection risk across bird species in the United States. Scientists have long known that certain bird behaviors and characteristics—such as moving in large groups, congregating in high-density wetlands, and long-distance migration patterns—make some species more susceptible to infection. But these traits do not operate in isolation, and their combined effects are often poorly understood. In addition, these behavioral traits are affected by biological characteristics of different species, such as infectability, viral shedding rates, survival time, and antibody development.
Thus far, researchers haven't fully understood how all these traits interact or why some bird species spread the virus more effectively, while others are more likely to die from it. To clarify this complexity, the authors propose a “HPAI host response continuum,” a flexible tool to determine whether individual species function primarily as victims of the virus, transmitters, or modifiers of how the disease spreads. The continuum is not fixed, and a given species’ role may shift depending on ecological context, population density, and viral evolution.
"This novel framework provides researchers and managers with a tool to adapt as new disease response information becomes available,” said Johanna Harvey (‘2018 PhD), co-first author on the monograph, now an assistant professor at the University of Rhode Island. “This is particularly useful as the range of hosts affected by H5N1 has continued to broaden."
Beyond wild bird populations, the monograph examines spillover risk to domestic poultry. Although outbreaks at poultry facilities are linked to infected wild waterfowl, the mechanisms of spillover and the roles of different species remain unclear. Factors such as poultry farm locations, surrounding habitat characteristics, facility type, species of poultry raised, and biosecurity practices all influence risk, yet fine-scale data are often unavailable. The work highlights emerging modeling approaches designed to bridge these information gaps.
Importantly, the monograph prioritizes management application, including sections on surveillance strategies, animal movements, management options for preventing outbreaks in wild populations and domestic flocks, and the integration of science into decision-making. The authors recommend that surveillance and management efforts prioritize vulnerable bird species of conservation concern, highly abundant bird species that are effective at transmitting the virus, and locations where birds gather in large numbers during migration.
As avian influenza continues to evolve and adapt to new bird hosts, the authors emphasize that management strategies must be flexible and adaptive. The work provides a framework for integrating new scientific findings as they emerge and for communicating both what we know and what remains uncertain about this complex ecological system.
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In addition to Mullinax and Harvey, additional authors of the monograph associated with UMD are postdoctoral associate and co-first author Matthew Gonnerman, and alumna Diann J. Prosser (‘2022 PhD ENST) currently with USGS.
