Pathogens take wings: disease transmission in migratory birds along the Palearctic-African flyway

Status
Currently In Progress
Overview
Recently there has been a dramatic rise in arboviral and other zoonotic diseases affecting both humans and
domestic animals. Migratory birds play a critical role in spreading such diseases, notably avian influenza
viruses (AIV) and Newcastle disease virus (NDV). Stopover sites on migration pathways can serve as
pathogen transmission hot spots, where species from disparate locations come together at high densities. We
propose to investigate pathogen transmission and transport in a multi-host, multi-pathogen migratoryresident
system, focused on a critical stopover site funneling migratory birds through a bottleneck in Israel in
the Palearctic-African flyway. The general aim of the proposal is to obtain a clearer understanding of how
migration impacts the evolutionary ecology of hosts and pathogens within migratory host populations and
also within a multispecies host community residing in an area ephemerally used by several migratory
populations. We propose to meet these aims by tagging and telemetrically tracking the movement of ten
migrating species that breed in a Palearctic region, overwinter in an African region and spend time in Israel
when flying between these regions. Individuals of these species along with individuals from five species that
do not migrate will be sampled intensively and systematically within Israel. Comparisons between resident
and migratory subpopulations will be conducted on five of the focal species and tagged migratory species
will be sampled in their breeding and overwinter grounds. The physiological, immunological and pathogeninfected
states of these individuals will be recorded and assessed, where the pathogens include, AIV, NDV,
bacterial species of zoonotic interest (e.g. salmonella) and malarial parasites (plasmodium). These
individual-state data, along with high resolution movement and pathogen genomic data will be analyzed to
assess relationships to help explain observed timing, intensity and spread of diseases within and beyond
Israel. We also plan to develop an agent-based general modeling framework that can be used to assess
causative relationships among correlated variables and apply these models to predict responses of these
disease systems (in the context of epidemics and pandemics) to both land use practices and global change.
Intellectual Merit
In a 2011 review, Altizer and colleagues wrote: "Studies of pathogen dynamics in migratory species and how
these will respond to global change are urgently needed to predict future disease risks for wildlife and
humans alike." Our project pushes this agenda forward in a migratory bird system. We will not only collect
baseline individual condition and disease state data of birds in the Palearctic flyway, but we will gain
insights into to the role that any highly connected node plays in terms of mediating the disease process in
otherwise peripheral regions connected to each other through this mixing node. Thus the proposed research
will provide new insights into the role that migrant populations play in the emergence and maintenance of
widely distributed pathogens. It will also provide new methods and tools for describing and predicting
disease transmission by migrating birds; in particular, tools that will be useful both for human and livestock
health, and for the conservation and management of wildlife. The approach we take in combining empirical
methods, statistical analyses and computational models will be broadly applicable to disease transmission in
the many other bird and animal migration systems throughout the world.
Broader Impacts
Beyond providing a cadre of students, including those under-represented in S.T.E.M, with regard to
methods for collecting and analysing data, and building models to help interpret relationships supported by
the data, we will reach out to a much broader student and professional community. We will do this through
publications, focussed scientific and modeling training workshops, a project website and the construction of
online modeling apps, available at (http://www.cs.oberlin.edu/~rms/novaol/; Username: nsfeeid; Password:
nsfeeid) that can be used in education at the K-12, college, and research training levels, as well as provide
tools to professional epidemiologists to help manage outbreaks of disease that could become global
pandemics. In addition, the research models we develop to forecast responses of the Palearctic-African
system to global change will be implemented to run using massively parallel technologies, and a website will
be set up to engage citizen scientists along the lines of the Folding@home project out of Stanford University.