| 1. |
- Gunnarsson, Gunnar, 1976-, et al.
(författare)
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Disease dynamics and bird migration : linking mallards Anas platyrhynchos and subtype diversity of the influenza A virus in time and space
- 2012
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Ingår i: PLOS ONE. - 1932-6203. ; 7:4, s. e35679-
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Tidskriftsartikel (refereegranskat)abstract
- The mallard Anas platyrhynchos is a reservoir species for influenza A virus in the northern hemisphere, with particularly high prevalence rates prior to as well as during its prolonged autumn migration. It has been proposed that the virus is brought from the breeding grounds and transmitted to conspecifics during subsequent staging during migration, and so a better understanding of the natal origin of staging ducks is vital to deciphering the dynamics of viral movement pathways. Ottenby is an important stopover site in southeast Sweden almost halfway downstream in the major Northwest European flyway, and is used by millions of waterfowl each year. Here, mallards were captured and sampled for influenza A virus infection, and positive samples were subtyped in order to study possible links to the natal area, which were determined by a novel approach combining banding recovery data and isotopic measurements (δ2H) of feathers grown on breeding grounds. Geographic assignments showed that the core natal areas of studied mallards were in Estonia, southern and central Finland, and northwestern Russia. This study demonstrates a clear temporal succession of latitudes of natal origin during the course of autumn migration. We also demonstrate a corresponding and concomitant shift in virus subtypes. Acknowledging that these two different patterns were based in part upon different data, a likely interpretation worth further testing is that the early arriving birds with more proximate origins have different influenza A subtypes than the more distantly originating late autumn birds. If true, this knowledge would allow novel insight into the origins and transmission of the influenza A virus among migratory hosts previously unavailable through conventional approaches.
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| 2. |
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| 4. |
- Hobson, Keith A., et al.
(författare)
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A feather hydrogen isoscape for Mexico
- 2009
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Ingår i: Journal of Geochemical Exploration. - : Elsevier BV. - 0375-6742. ; 102:2, s. 63-70
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Tidskriftsartikel (refereegranskat)abstract
- Developing useful biological isoscapes for areas of the world is a priority. This is the case for Mexico that hosts a large percentage of North America's Neotropical migrant birds. Here we investigated the use of House Sparrow (Passer domesticus) feathers to create a spatially explicit feather deuterium isoscape for that country using samples (n=461) that were collected across Mexico. Considerable and useful spatial hydrogen isotopic structure was observed, suggesting that isotopes may be a potential forensic tool for evaluating origins of Mexican derived fauna and. ora. The most positive feather delta D values occurred in the northeast and most negative in the south-central part of the country, roughly matching delta D patterns observed in groundwater. A weak negative isotopic relationship was found with altitude in both the Pacific and Atlantic drainage systems. The most parsimonious model describing isotopic spatial variation in feathers between 300 and 3000 m a.s.l. included groundwater delta D (delta D-gw; precipitation proxy), sex, amount of precipitation, and the coefficient of variation in amount of precipitation. Overall, delta D-gw was a poor predictor of sparrow delta D-f values for all of Mexico. However, this relationship was considerably strengthened when we considered sex separately, removed the Baja peninsula from our sample, and considered the Atlantic and Pacific drainage basins separately. The strongest relationship between delta D-gw and delta D-f was found for female sparrows in the Atlantic drainage basin (r(2)=0.464). We recommend that researchers interested in inferring origins of migratory birds and other animals in Mexico create species specific isotopic basemaps that may be guided by the isotopic patterns we have observed for House Sparrows and groundwater. (C) 2009 Published by Elsevier B.V.
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| 5. |
- Hobson, Keith A., et al.
(författare)
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A feather hydrogen isoscape for Mexico
- 2009
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Ingår i: Journal of Geochemical Exploration. - : Elsevier BV. - 0375-6742 .- 1879-1689. ; 102:3, s. 167-174
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Tidskriftsartikel (refereegranskat)abstract
- Developing useful biological isoscapes for areas of the world is a priority. This is the case for Mexico that hosts a large percentage of North America's Neotropical migrant birds. Here we investigated the use of House Sparrow (Passer domesticus) feathers to create a spatially explicit feather deuterium isoscape for that country using samples (n=461) that were collected across Mexico. Considerable and useful spatial hydrogen isotopic structure was observed, suggesting that isotopes may be a potential forensic tool for evaluating origins of Mexican derived fauna and flora. The most positive feather delta D values occurred in the northeast and most negative in the south-central part of the country, roughly matching delta D patterns observed in groundwater. A weak negative isotopic relationship was found with altitude in both the Pacific and Atlantic drainage systems. The most parsimonious model describing isotopic spatial variation in feathers between 300 and 3000 m a.s.l. included groundwater delta D (delta D-gw; precipitation proxy), sex, amount of precipitation, and the coefficient of variation in amount of precipitation. Overall, delta D-gw was a poor predictor of sparrow delta D-f values for all of Mexico. However, this relationship was considerably strengthened when we considered sex separately, removed the Baja peninsula from our sample, and considered the Atlantic and Pacific drainage basins separately. The strongest relationship between delta D-gw and delta D-f was found for female sparrows in the Atlantic drainage basin (r(2)=0.464). We recommend that researchers interested in inferring origins of migratory birds and other animals in Mexico create species specific isotopic basemaps that may be guided by the isotopic patterns we have observed for House Sparrows and groundwater. (C) 2009 Published by Elsevier B.V.
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| 6. |
- Hobson, Keith A., et al.
(författare)
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Linking Hydrogen (δ2H) Isotopes in Feathers and Precipitation : sources of Variance and Consequences for Assignment to Isoscapes
- 2012
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:4
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Tidskriftsartikel (refereegranskat)abstract
- Tracking small migrant organisms worldwide has been hampered by technological and recovery limitations and sampling bias inherent in exogenous markers. Naturally occurring stable isotopes of H (δ2H) in feathers provide an alternative intrinsic marker of animal origin due to the predictable spatial linkage to underlying hydrologically driven flow of H isotopes into foodwebs. This approach can assess the likelihood that a migrant animal originated from a given location(s) within a continent but requires a robust algorithm linking H isotopes in tissues of interest to an appropriate hydrological isotopic spatio-temporal pattern, such as weighted-annual rainfall. However, a number of factors contribute to or alter expected isotopic patterns in animals. We present results of an extensive investigation into taxonomic and environmental factors influencing feather δ2H patterns across North America. Stable isotope data were measured from 544 feathers from 40 species and 140 known locations. For δ2H, the most parsimonious model explaining 83% of the isotopic variance was found with amount-weighted growing-season precipitation δ2H, foraging substrate and migratory strategy. This extensive H isotopic analysis of known-origin feathers of songbirds in North America and elsewhere reconfirmed the strong coupling between tissue δ2H and global hydrologic δ2H patterns, and accounting for variance associated with foraging substrate and migratory strategy, can be used in conservation and research for the purpose of assigning birds and other species to their approximate origin.
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| 7. |
- Prochazka, Petr, et al.
(författare)
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Using stable hydrogen isotopes (delta H-2) and ring recoveries to trace natal origins in a Eurasian passerine with a migratory divide
- 2013
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Ingår i: Journal of Avian Biology. - 0908-8857. ; 44:6, s. 541-550
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Tidskriftsartikel (refereegranskat)abstract
- Despite recent advances in technology, it remains difficult to connect breeding and non-breeding areas of populations of migratory organisms due to the challenges of year-round tracking. Here, we used the Eurasian reed warbler Acrocephalus scirpaceus, a passerine with a pronounced migratory divide to demonstrate the promise of integrating several sources of information within the Bayesian modelling framework for the study of migratory connectivity. To this end, we combined data from stable hydrogen isotope ratios (H-2) of feathers, ring recoveries, and the geographic delineation of sub-populations on either side of the migratory divide. Feather H-2 measurements from local juvenile birds sampled across the breeding range tightly correlated with amount-weighted mean annual precipitation H-2 values predicted for the natal sites. Predicted natal origins of birds intercepted en route in the Mediterranean region largely differed among the five stopover sites. Thanks to the different migratory pathways used by different breeding populations and the existence of a migratory divide, we were able to effectively narrow the assigned regions of origin. Our results show that spatial resolution of likelihood-based assignments of geographic origins based on H-2 measurements may improve significantly when prior probabilities derived from population-specific migratory directions are included. Integrating information from stable isotopes, ring recoveries, geolocators and other sources within the Bayesian modelling framework will provide an extremely useful toolbox for the study of animal movements in the future.
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| 8. |
- Veen, Thor, et al.
(författare)
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Identifying the African Wintering Grounds of Hybrid Flycatchers Using a Multi-Isotope (delta H-2, delta C-13, delta N-15) Assignment Approach
- 2014
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:5, s. e98075-
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Tidskriftsartikel (refereegranskat)abstract
- Migratory routes and wintering grounds can have important fitness consequences, which can lead to divergent selection on populations or taxa differing in their migratory itinerary. Collared (Ficedula albicollis) and pied (F. hypoleuca) flycatchers breeding in Europe and wintering in different sub-Saharan regions have distinct migratory routes on the eastern and western sides of the Sahara desert, respectively. In an earlier paper, we showed that hybrids of the two species did not incur reduced winter survival, which would be expected if their migration strategy had been a mix of the parent species' strategies potentially resulting in an intermediate route crossing the Sahara desert to different wintering grounds. Previously, we compared isotope ratios and found no significant difference in stable-nitrogen isotope ratios (delta N-15) in wintergrown feathers between the parental species and hybrids, but stable-carbon isotope ratios (delta C-13) in hybrids significantly clustered only with those of pied flycatchers. We followed up on these findings and additionally analyzed the same feathers for stable-hydrogen isotope ratios (delta H-2) and conducted spatially explicit multi-isotope assignment analyses. The assignment results overlapped with presumed wintering ranges of the two species, highlighting the efficacy of the method. In contrast to earlier findings, hybrids clustered with both parental species, though most strongly with pied flycatcher.
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