Bird migration and avian influenza: A comparison of hydrogen stable isotopes and satellite tracking methods

Abstract

Satellite-based tracking of migratory waterfowl is an important tool for understanding the potential role of wild birds in the long-distance transmission of highly pathogenic avian influenza. However, employing this technique on a continental scale is prohibitively expensive. This study explores the utility of stable isotope ratios in feathers in examining both the distances traveled by migratory birds and variation in migration behavior. We compared the satellite-derived movement data of 22 ducks from 8 species captured at wintering areas in Bangladesh, Turkey, and Hong Kong with deuterium ratios (δD) of these and other individuals captured at the same locations. We derived likely molting locations from the satellite tracking data and generated expected isotope ratios based on an interpolated map of δD in rainwater. Although δD was correlated with the distance between wintering and molting locations, surprisingly, measured δD values were not correlated with either expected values or latitudes of molting sites. However, population-level parameters derived from the satellite-tracking data, such as mean distance between wintering and molting locations and variation in migration distance, were reflected by means and variation of the stable isotope values. Our findings call into question the relevance of the rainfall isotope map for Asia for linking feather isotopes to molting locations, and underscore the need for extensive ground truthing in the form of feather-based isoscapes. Nevertheless, stable isotopes from feathers could inform disease models by characterizing the degree to which regional breeding populations interact at common wintering locations. Feather isotopes also could aid in surveying wintering locations to determine where high-resolution tracking techniques (e.g. satellite tracking) could most effectively be employed. Moreover, intrinsic markers such as stable isotopes offer the only means of inferring movement information from birds that have died as a result of infection. In the absence of feather based-isoscapes, we recommend a combination of isotope analysis and satellite-tracking as the best means of generating aggregate movement data for informing disease models.

Toward a Deuterium Feather Isoscape for Sub-Saharan Africa: Progress, Challenges and the Path Ahead

“…An alternate approach is to derive a feather δ 2 H isoscape directly by collecting feathers from known origins across the continent [17, 13], but little direct information exists about the stable isotope distribution in feathers along the Afrotropical areas. Feather δ 2 H isoscapes created using ground-truthed rescaling functions are therefore required to improve assignment accuracy in these areas [18, 19]. In Africa, widespread feather sampling is logistically extremely difficult but museum collections can be used as a source of feather samples at a continental scale.…”

Stable Isotopes Suggest Low Site Fidelity in Bar-Headed Geese (Anser indicus) in Mongolia: Implications for Disease Transmission

“…Understanding how different regional breeding populations may intermingle during the migratory or wintering phases of their annual cycle can help prioritize conservation efforts and can inform continental-scale studies of disease transmission (Faaborg et al . 2010; Bridge et al . 2014; Runge et al .…”

Predicting the initial spread of novel Asian origin influenza A viruses in the continental USA by wild waterfowl

“…In emergency outbreak situations, decisions and strategies must be developed and implemented rapidly; band‐recovery data were an easily accessible resource that could be integrated into a targeted sampling strategy that could be deployed quickly. A number of studies (Bridge et al., ; Gunnarsson et al., ) have employed satellite telemetry, genetics and stable isotopes to link waterfowl movement with large‐scale spatial and temporal distributions of avian influenza viruses. While excellent tools for research, these techniques are not always feasible to rapidly inform emergency‐response situations because they provide information after sampling has taken place rather than guiding sampling in the beginning.…”

“…In emergency outbreak situations, decisions and strategies must be developed and implemented rapidly; band-recovery data were an easily accessible resource that could be integrated into a targeted sampling strategy that could be deployed quickly. A number of studies (Bridge et al, 2014;Gunnarsson et al, 2012) 2009), and (c) incorporating more rigorous estimators into the predictive modelling process (e.g., Buhnerkempe et al, 2016).…”