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At least 307 records · Page 17Linked to original sources

USGS2014

Prioritizing bird conservation actions in the Prairie Hardwood transition of the Midwestern United States

Large-scale planning for the conservation of species is often hindered by a poor understanding of factors limiting populations. In regions with declining wildlife populations, it is critical that objective metrics of conservation success are developed to ensure that conservation actions achieve desired results. Using spatially explicit estimates of bird abundance, we evaluated several management alternatives for conserving bird populations in the Prairie Hardwood Transition of the United States. We designed landscapes conserving species at 50% of their current predicted abundance as well as landscapes attempting to achieve species population targets (which often required the doubling of current abundance). Conserving species at reduced (half of current) abundance led to few conservation conflicts. However, because of extensive modification of the landscape to suit human use, strategies for achieving regional population targets for forest bird species would be difficult under even ideal circumstances, and even more so if maintenance of grassland bird populations is also desired. Our results indicated that large-scale restoration of agricultural lands to native grassland and forest habitats may be the most productive conservation action for increasing bird population sizes but the level of landscape transition required to approach target bird population sizes may be societally unacceptable.

Illinois;Indiana;Iowa;Michigan;Minnesota;Wisconsin↗

USGS2005

Prey consumption and energy transfer by marine birds in the Gulf of Alaska

We investigated prey consumption by marine birds and their contribution to cross-shelf fluxes in the northern Gulf of Alaska. We utilized data from the North Pacific Pelagic Seabird Database for modeling energy demand and prey consumption. We found that prey consumption by marine birds was much greater over the continental shelf than it was over the basin. Over the shelf, subsurface-foraging marine birds dominated food consumption, whereas over the basin, surface-foraging birds took the most prey biomass. Daily consumption by marine birds during the non-breeding season ("winter") from September through April was greater than daily consumption during the breeding season, between May and August. Over the shelf, shearwaters, murres and, in winter, sea ducks, were the most important consumers. Over the basin, northern fulmars, gulls and kittiwakes predominated in winter and storm-petrels dominated in May to August. Our results suggest that marine birds contribute little to cross-shelf fluxes of energy or matter, but they do remove energy from the marine system through consumption, respiration and migration. ?? 2005 Elsevier Ltd. All rights reserved.

Conference Paper↗

USGS2025

Foraging of wading birds on a patchy landscape: Simulating effects of social information, interference competition, and patch selection on prey intake and individual distribution

Foragers on patchy landscapes must acquire sufficient resources despite uncertainty in the location and amount of the resources. Optimal Foraging Theory posits that foragers deal with this uncertainty by using strategies that optimize resource intake within foraging periods. For species such as wading birds, this optimization is closely linked to their survival and reproductive success. Understanding the influence of patch selection on individual resource intake and foraging distribution is therefore crucial. In this study, we simulated how resource distribution, interference competition, and social cues—such as aggregation behaviors—influence resource intake and foraging spatial distribution. We employed an individual-based model simulating wading bird foraging behaviors, with 900 individuals simultaneously foraging across a landscape with unknown resource distribution. Birds employed one of three patch-finding strategies: random, cue-searching, or hybrid, which uses both searching strategies. Each bird decided whether to remain in a patch based on a prey density threshold. We compared the daily resource intake and foraging distribution of birds across different modeled patch-finding strategies, resource distribution patterns, and the presence or absence of interference competition. Wading birds exhibiting aggregation behavior displayed increased intake rates when resources were concentrated and interference minimal. Aggregation behavior led to a closer match with the ideal free distribution when the prey density threshold was optimal. These findings provide theoretical support that aggregation behavior is effective in scenarios where resources are concentrated in a few patches, social cues are used by relatively few individuals, and interference competition is limited.

Ecological Modelling↗

USGS2023

Climate-induced shifts in grassland bird nesting phenology have implications for grassland management

Grasslands are among the most impacted ecosystems globally. In the midcontinent of North America, a > 80% loss of grasslands has made their conservation a major priority for resource managers. Grassland ecosystems evolved under periodic disturbances; consequently, grassland management often involves regular actions such as grazing, haying, or burning to maintain ecosystem integrity. The timing of such practices has direct implications on grassland ecology, agricultural economics, and survival and fecundity of grassland nesting birds (hereafter grassland birds). We conducted a meta-analysis on the nesting phenology of grassland birds throughout North America, focusing on nest-survival literature. We constructed a well-fitting model to predict median date of expected nest departure (hereafter fledge date) for grassland birds across the midcontinent. Predictions from our model demonstrate considerable spatial variation in median nesting phenology that is predictable using a spatially explicit spring phenology index. Median fledge dates were 8 or 13 days earlier in years of extreme weather conditions (dry or wet, respectively) than in years of average conditions. Species that generally nest in taller vegetation tended to have later median nest phenologies than those using shorter vegetation. Our results incorporate the most rigorous information available in the literature on nesting phenology of 36 grassland bird species and improve information available to managers about nesting phenology of grassland birds in the midcontinent of North America. Our predictions approximate the day when one-half of the nesting efforts would be complete for a given area within the midcontinent grasslands and can inform management and conservation decisions about the timing of management actions in grassland ecosystems.

Global Ecology and Conservation↗

USGS2025

Forest bird population status on Saipan, a small oceanic island

Tropical oceanic islands are critical biodiversity hotspots where population monitoring can help to determine the status and trends of rare and endangered species. Saipan is the second largest island in the Mariana Islands and contains many endemic and range-restricted bird species. Surveys of forest birds were conducted on Saipan using point-transect distance sampling, starting in 1982. To determine population status for Saipan avifauna, we generated abundance estimates based on surveys conducted in 1982, 1997, 2007, and 2018. We also assessed community composition by exploring if there were changes in assemblage diversity, total forest bird abundance, and ratio of native to non-native populations over time. For the 2018 survey, there were 5791 detections of 18 species during 242 counts, with six of 18 species detected at > 50 % of the counts and with relatively high abundance, while 12 species were detected at < 50 % of the counts and were uncommon or rare. The most abundant species was Bridled White eye (nosa', Zosterops conspicillatus saypani ) at > 40 birds/ha and the least common species was the Saipan Reed Warbler (gå'ga' karisu, Acrocephalus hiwae) at < 1 bird/ha. We found that the community composition is becoming slightly more even over time and the overall community abundance is stable (around 375,000 birds), but non-native species have become more common while native species have remained stable. Results from this study can be used to inform conservation management of forest birds in Saipan and contribute to a broader understanding of forest bird status in the Marianas.

Saipan↗

USGS2024

Strategic restoration planning for land birds in the Colorado River Delta, Mexico

Ecological restoration is an essential strategy for mitigating the current biodiversity crisis, yet restoration actions are costly. We used systematic conservation planning principles to design an approach that prioritizes restoration sites for birds and tested it in a riparian forest restoration program in the Colorado River Delta. Restoration goals were to maximize the abundance and diversity of 15 priority birds with a variety of habitat preferences. We built abundance models for priority birds based on the current landscape, and predicted bird distributions and relative abundances under a scenario of complete riparian forest restoration throughout our study area. Then, we used Zonation conservation planning software to rank this restored landscape based on core areas for all priority birds. The locations with the highest ranks represented the highest priorities for restoration and were located throughout the river reach. We optimized how much of the available landscape to restore by simulating restoration of the top 10–90% of ranked sites in 10% intervals. We found that total diversity was maximized when 40% of the landscape was restored, and mean relative abundance was maximized when 80% of the landscape was restored. The results suggest that complete restoration is not optimal for this community of priority birds and restoration of approximately 60% of the landscape would provide a balance between maximum relative abundance and diversity. Subsequent planning efforts will combine our results with an assessment of restoration costs to provide further decision support for the restoration-siting process. Our approach can be applied to any landscape-scale restoration program to improve the return on investment of limited economic resources for restoration.

Colorado River Delta↗

USGS2017

Rodenticide incidents of exposure and adverse effects on non-raptor birds

Interest in the adverse effects of rodenticides on birds has focused primarily on raptors. However, non-raptor birds are also poisoned (rodenticide exposure resulting in adverse effects including mortality) by rodenticides through consumption of the rodenticide bait and contaminated prey. A literature search for rodenticide incidents (evidence of exposure to a rodenticide, adverse effects, or exposure to placebo baits) involving non-raptor birds returned 641 records spanning the years 1931 to 2016. The incidents included 17 orders, 58 families, and 190 non-raptor bird species. Nineteen anticoagulant and non-anticoagulant rodenticide active ingredients were associated with the incidents. The number of incidents and species detected were compared by surveillance method. An incident was considered to have been reported through passive surveillance if it was voluntarily reported to the authorities whereas the report of an incident found through field work that was conducted with the objective of documenting adverse effects on birds was determined to be from active surveillance. More incidents were reported from passive surveillance than with active surveillance but a significantly greater number of species were detected in proportion to the number of incidents found through active surveillance than with passive surveillance (z = 7.61, p < 0.01). Results suggest that reliance on only one surveillance method can underestimate the number of incidents that have occurred and the number of species that are affected. Although rodenticides are used worldwide, incident records were found from only 15 countries. Therefore, awareness of the breadth of species diversity of non-raptor bird poisonings from rodenticides may increase incident reportings and can strengthen the predictions of harm characterized by risk assessments.

Science of the Total Environment↗

USGS2002

Mercury in feathers from Chilean birds: Influence of location, feeding strategy, and taxonomic affiliation

This study reports baseline concentrations of mercury (Hg) in feathers from different species of birds sampled at various locations off the Chilean coast (Southeastern Pacific). Hg concentrations were evaluated in relation to geographic location, taxonomic affiliation, and feeding strategies. Between January and March of 1995, we collected mature contour feathers from 116 birds belonging to 22 species, mostly seabirds. Birds were collected from 10 different locations (26??09???S, 70??40???W to 54??56???S, 67??37???W). Feather Hg concentrations ranged from 0.11 to 13 ??gg-1 dry weight. We found differences in feather Hg concentrations across taxonomic groups, with highest concentrations in petrels, shearwaters, and albatrosses (Procellaridae), followed by boobies (Sulidae), gulls, terns, skuas (Laridae) and cormorants (Phalacrocoracidae). Ibises and oystercatchers (Threskiornithidae and Charadriidae) had intermediate values, whereas ducks and geese (Anatidae) contained the least amount of Hg. Oceanic species preying on mesopelagic fish (the Procellariformes albatrosses, petrels, and fulmars) had over twice as much Hg (overall average of 3.9 ??gg-1) when compared to the rest of the species sampled (overall average of 1.5 ??gg-1). We did not find higher Hg concentrations in birds inhabiting the more heavily industrialized and urbanized areas of the country (central and northern regions), but in birds inhabiting the remote Juan Ferna??ndez Archipelago. This is not surprising, since all the Procellariformes (the group with highest Hg values in this study) were collected from these islands. Except for Hg in Kermadec petrels (mean of 12 ??gg-1), the range of Hg values reported here (0.11-7.3 ??gg-1) fell below those known to cause adverse health and reproductive effects in birds. ?? 2002 Elsevier Science Ltd. All rights reserved.

Marine Pollution Bulletin↗

USGS1999

Modeling bird mortality associated with the M/V Citrus oil spill off St. Paul Island, Alaska

We developed a model to estimate the number of bird carcasses that were likely deposited on the beaches of St. Paul Island, Alaska following the M/V Citrus oil spill in February 1996. Most of the islands beaches were searched on an irregular schedule, resulting in the recovery of 876 King Eider carcasses. A sub-sample of beaches were intensively studied to estimate daily persistence rate and detection probability [Fowler, A.C., Flint, P.L., 1997. Marine Pollution Bulletin]. Using these data, our model predicted that an additional 733±70 King Eider carcasses were not detected during our searches. Therefore, we estimate that at least 1609±70 King Eider carcasses occurred on beaches as a result of the spill. We lacked sufficient sample size to model losses for other species, thus we applied the estimated recovery rate for King Eiders (54%) to other species and estimate a total combined loss of 1765 birds. In addition, 165 birds were captured alive making the total estimated number of birds impacted by the M/V Citrus spill 1930. Given that oiled birds occurred in places on the island which could not be systematically searched combined with the fact that it was unlikely that oiled birds that died at sea would have been recovered during our searches [Flint, P.L., Fowler, A.C., 1998. Marine Pollution Bulletin], our estimate of total mortality associated with the spill should be considered a minimum.

Alaska↗

USGS1986

Bird predation on cutworms (Lepidoptera: Noctuidae) in wheat fields and chlorpyrifos effects on brain cholinesterase activity

Horned larks, Eremophila alpestris (L.), and McCown's longspurs, Calcarius mccownii (Lawrence), were collected at intervals from two winter wheat fields in Montana after aerial application of chlorpyrifos to control cutworms. Both bird species had a high (95–100%) incidence of Lepidoptera, mostly pale western cutworms, Agrotis orthogonia Morrison, in their stomachs at 3 days postspray. Incidence of cutworms and other insects in stomachs of birds from sprayed fields was lower at 9 and 16 days postspray than in control birds, presumably due to insecticide-caused reduction of insects. Effects of birds on population dynamics of insect pests in wheat are unknown, but birds do contribute to cutworm mortality. Predation is one of the limiting factors to cutworm increase and can supplement insecticidal control. Brain cholinesterase activity in horned larks collected from the sprayed fields at 3 and 9 days postspray was significantly lower than in unexposed larks, but at 16 days the difference was not significant. Although nontarget birds clearly were exposed to chlorpyrifos and manifested a sublethal physiological response, toxic effects were lesssevere than those resulting from endrin application for cutworm control in wheat. More study is needed of larger chlorpyrifos-treated fields under a variety of conditions to fully assess effects on nontarget life.

Environmental Entomology↗

USGS2025

Accounting for seasonal patterns in bird availability prevents biased population trend estimates with advancing spring phenology

Advancing spring phenology has been observed around the world, including changes in the timing of breeding of birds. When singing rates are tied to breeding stage, the rate at which birds are available for detection by surveyors can also show seasonal patterns that may shift with spring phenology. As the timing of peak bird availability changes over years, monitoring programs that do not account for changing availability could incorrectly conclude that there is a change in population size. We used a 20-yr point-count dataset to test for relationships between bird availability and spring vegetation phenology for 27 species in boreal Alaska. Nine of 22 migratory species showed a significant effect of day of spring (DOS) on availability, usually with availability declining over the survey window (late spring and early summer). In contrast, 3 of 5 resident species showed availability increasing over the survey window. We then conducted a simulation study to evaluate how changing spring phenology could affect estimates of population trend under a static survey window. We found that including DOS in the model as a covariate of availability prevented bias in the trend estimates and did not reduce precision. However, when the model ignored the effect of DOS on availability, population trend estimates were often significantly biased when spring phenology was advancing. Our study adds to previous evidence that bird availability is often related to spring phenology, and demonstrates that failing to account for seasonal changes in availability could result in the spurious estimation of a population trend when spring phenology changes over time. In some cases, the bias could be large enough to change species status assessments under IUCN Red List Criteria. Monitoring programs for birds and other taxa with seasonally varying availability could avoid bias by simply measuring and modeling the relationship between DOS and availability.

Alaska↗

USGS2016

Immunoglobulin detection in wild birds: Effectiveness of three secondary anti-avian IgY antibodies in direct ELISAs in 41 avian species

1.Immunological reagents for wild, non-model species are limited or often non-existent for many species. 2. In this study, we compare the reactivity of a new anti-passerine IgY secondary antibody with existing secondary antibodies developed for use with birds. Samples from 41 species from the following six avian orders were analysed: Anseriformes (1 family, 1 species), Columbiformes (1 family, 2 species), Galliformes (1 family, 1 species), Passeriformes (16 families, 34 species), Piciformes (1 family, 2 species) and Suliformes (1 family, 1 species). Direct ELISAs were performed to detect total IgY using goat anti-passerine IgY, goat anti-chicken IgY or goat anti-bird IgY secondary antibodies. 3.The anti-passerine antibody exhibited significantly higher IgY reactivity compared to the anti-chicken and/or anti-bird antibodies in 80% of the passerine families tested. Birds in the order Piciformes (woodpeckers) and order Suliformes (cormorants) were poorly detected by all three secondary antibodies. A comparison of serum and plasma IgY levels was made within the same individuals for two passerine species (house finch and white-crowned sparrow), and serum exhibited significantly more IgY than the plasma for all three secondary antibodies. This result indicates that serum may be preferred to plasma when measuring total antibody levels in blood. 4.This study indicates that the anti-passerine IgY secondary antibody can effectively be used in immunological assays to detect passerine IgY for species in most passerine families and is preferred over anti-chicken and anti-bird secondary antibodies for the majority of passerine species. This anti-passerine antibody will allow for more accurate detection and quantification of IgY in more wild bird species than was possible with previously available secondary antibodies.

Methods in Ecology and Evolution↗

USGS2024

The geographic extent of bird populations affected by renewable-energy development

Bird populations are declining globally. Wind and solar energy can reduce emissions of fossil fuels that drive anthropogenic climate change, yet renewable-energy production represents a potential threat to bird species. Surveys to assess potential effects at renewable-energy facilities are exclusively local, and the geographic extent encompassed by birds killed at these facilities is largely unknown, which creates challenges for minimizing and mitigating the population-level and cumulative effects of these fatalities. We performed geospatial analyses of stable hydrogen isotope data obtained from feathers of 871 individuals of 24 bird species found dead at solar- and wind-energy facilities in California (USA). Most species had individuals with a mix of origins, ranging from 23% to 98% nonlocal. Mean minimum distances to areas of likely origin for nonlocal individuals were as close as 97 to >1250 km, and these minimum distances were larger for species found at solar-energy facilities in deserts than at wind-energy facilities in grasslands (Cohen's d = 6.5). Fatalities were drawn from an estimated 30–100% of species’ desingated ranges, and this percentage was significantly smaller for species with large ranges found at wind facilities (Pearson's r = −0.67). Temporal patterns in the geographic origin of fatalities suggested that migratory movements and nonmigratory movements, such as dispersal and nomadism, influence exposure to fatality risk for these birds. Our results illustrate the power of using stable isotope data to assess the geographic extent of renewable-energy fatalities on birds. As the buildout of renewable-energy facilities continues, accurate assessment of the geographic footprint of wildlife fatalities can be used to inform compensatory mitigation for their population-level and cumulative effects.

Conservation Biology↗

USGS2008

Desert bird associations with broad-scale boundary length: Applications in avian conservation

1. Current understanding regarding the effects of boundaries on bird communities has originated largely from studies of forest-non-forest boundaries in mesic systems. To assess whether broad-scale boundary length can affect bird community structure in deserts, and to identify patterns and predictors of species' associations useful in avian conservation, we studied relations between birds and boundary-length variables in Chihuahuan Desert landscapes. Operationally, a boundary was the border between two adjoining land covers, and broad-scale boundary length was the total length of such borders in a large area. 2. Within 2-km radius areas, we measured six boundary-length variables. We analysed bird-boundary relations for 26 species, tested for assemblage-level patterns in species' associations with boundary-length variables, and assessed whether body size, dispersal ability and cowbird-host status were correlates of these associations. 3. The abundances or occurrences of a significant majority of species were associated with boundary-length variables, and similar numbers of species were related positively and negatively to boundary-length variables. 4. Disproportionately small numbers of species were correlated with total boundary length, land-cover boundary length and shrubland-grassland boundary length (variables responsible for large proportions of boundary length). Disproportionately large numbers of species were correlated with roadside boundary length and riparian vegetation-grassland boundary length (variables responsible for small proportions of boundary length). Roadside boundary length was associated (positively and negatively) with the most species. 5. Species' associations with boundary-length variables were not correlated with body size, dispersal ability or cowbird-host status. 6. Synthesis and applications. For the species we studied, conservationists can use the regressions we report as working models to anticipate influences of boundary-length changes on bird abundance and occurrence, and to assess avifaunal composition for areas under consideration for protection. Boundary-length variables associated with a disproportionate or large number of species can be used as foci for landscape management. Assessing the underlying causes of bird-boundary relations may improve the prediction accuracy of associated models. We therefore advocate local- and broad-scale manipulative experiments involving the boundary types with which species were correlated, as indicated by the regressions. ?? 2008 The Authors.

Journal of Applied Ecology↗

USGS2008

Tamarix as habitat for birds: Implications for riparian restoration in the Southwestern United States

Exotic vegetation has become a major habitat component in many ecosystems around the world, sometimes dramatically changing the vegetation community structure and composition. In the southwestern United States, riparian ecosystems are undergoing major changes in part due to the establishment and spread of the exotic Tamarix (saltcedar, tamarisk). There are concerns about the suitability of Tamarix as habitat for birds. Although Tamarix habitats tend to support fewer species and individuals than native habitats, Arizona Breeding Bird Atlas data and Birds of North America accounts show that 49 species use Tamarix as breeding habitat. Importantly, the relative use of Tamarix and its quality as habitat vary substantially by geographic location and bird species. Few studies have examined how breeding in Tamarix actually affects bird survivorship and productivity; recent research on Southwestern Willow Flycatchers has found no negative effects from breeding in Tamarix habitats. Therefore, the ecological benefits and costs of Tamarix control are difficult to predict and are likely to be species specific and site specific. Given the likelihood that high-quality native riparian vegetation will not develop at all Tamarix control sites, restoration projects that remove Tamarix but do not assure replacement by high-quality native habitat have the potential to reduce the net riparian habitat value for some local or regional bird populations. Therefore, an assessment of potential negative impacts is important in deciding if exotic control should be conducted. In addition, measurable project objectives, appropriate control and restoration techniques, and robust monitoring are all critical to effective restoration planning and execution. ?? 2008 Society for Ecological Restoration International.

Restoration Ecology↗

USGS2020

Diurnal timing of nonmigratory movement by birds: The importance of foraging spatial scales

Timing of activity can reveal an organism's efforts to optimize foraging either by minimizing energy loss through passive movement or by maximizing energetic gain through foraging. Here, we assess whether signals of either of these strategies are detectable in the timing of activity of daily, local movements by birds. We compare the similarities of timing of movement activity among species using six temporal variables: start of activity relative to sunrise, end of activity relative to sunset, relative speed at midday, number of movement bouts, bout duration, and proportion of active daytime hours. We test for the influence of flight mode and foraging habitat on the timing of movement activity across avian guilds. We used 64570 days of GPS movement data collected between 2002 and 2019 for local (non‐migratory) movements of 991 birds from 49 species, representing 14 orders. Dissimilarity among daily activity patterns was best explained by flight mode. Terrestrial soaring birds began activity later and stopped activity earlier than pelagic soaring or flapping birds. Broad‐scale foraging habitat explained less of the clustering patterns because of divergent timing of active periods of pelagic surface and diving foragers. Among pelagic birds, surface foragers were active throughout the day while diving foragers matched their active hours more closely to daylight hours. Pelagic surface foragers also had the greatest daily foraging distances, which was consistent with their daytime activity patterns. This study demonstrates that flight mode and foraging habitat influence temporal patterns of daily movement activity of birds.

Journal of Avian Biology↗

USGS2026

Assessing working lands as habitat for disturbance-dependent birds using autonomous recording units

Introduction Working lands can provide habitat for declining disturbance-dependent birds, such as Bachman's Sparrow ( Peucaea aestivalis ) and Northern Bobwhite ( Colinus virginianus ), but it remains unclear whether restoration following intensive land use (e.g. surface mining) yields habitat comparable to less intensive land uses (e.g. timber production). Objectives We evaluated effects of land use both in working lands (recently replanted surface mine reclamation site and recently replanted timber production site) and reference sites explicitly managed for wildlife (recently restored young pine savanna and mature pine savanna) and understory vegetation characteristics on relative abundance of disturbance-dependent birds within upland pine ( Pinus spp.) communities in southeastern Georgia, United States. We hypothesized that the mine reclamation site would support similar bird species but in lower relative abundances than other land uses. Methods We conducted daily acoustic surveys using autonomous recording units (ARUs) and measured vegetation surveys once per point from May to June 2024. We used Royle-Nichols models, an adapted occupancy model, to estimate relative abundance for eight bird species. Results Land use influenced relative abundance for all species and explained more variation in relative abundance than measured understory vegetation characteristics. The mining reclamation site supported most disturbance-dependent species and, in some cases, equal or higher relative abundances, particularly for Northern Bobwhite and Common Nighthawk ( Chordeiles minor ). Responses across timber production and savanna sites varied by species. Vegetation effects were generally weaker and species-specific, suggesting that land use history and associated habitat legacies play an important role in structuring these bird communities. Conclusion Working lands, including reclaimed mines, can provide habitat for disturbance-dependent birds, and ARUs are effective for evaluating these patterns across land uses.

Restoration Ecology↗

USGS2012

Eco-virological approach for assessing the role of wild birds in the spread of avian influenza H5N1 along the central Asian flyway

A unique pattern of highly pathogenic avian influenza (HPAI) H5N1 outbreaks has emerged along the Central Asia Flyway, where infection of wild birds has been reported with steady frequency since 2005. We assessed the potential for two hosts of HPAI H5N1, the bar-headed goose ( Anser indicus ) and ruddy shelduck ( Tadorna tadorna ), to act as agents for virus dispersal along this ‘thoroughfare’. We used an eco-virological approach to compare the migration of 141 birds marked with GPS satellite transmitters during 2005–2010 with: 1) the spatio-temporal patterns of poultry and wild bird outbreaks of HPAI H5N1, and 2) the trajectory of the virus in the outbreak region based on phylogeographic mapping. We found that biweekly utilization distributions (UDs) for 19.2% of bar-headed geese and 46.2% of ruddy shelduck were significantly associated with outbreaks. Ruddy shelduck showed highest correlation with poultry outbreaks owing to their wintering distribution in South Asia, where there is considerable opportunity for HPAI H5N1 spillover from poultry. Both species showed correlation with wild bird outbreaks during the spring migration, suggesting they may be involved in the northward movement of the virus. However, phylogeographic mapping of HPAI H5N1 clades 2.2 and 2.3 did not support dissemination of the virus in a northern direction along the migration corridor. In particular, two subclades (2.2.1 and 2.3.2) moved in a strictly southern direction in contrast to our spatio-temporal analysis of bird migration. Our attempt to reconcile the disciplines of wild bird ecology and HPAI H5N1 virology highlights prospects offered by both approaches as well as their limitations.

PLoS ONE↗