| 11. |
- Brattström, Oskar, et al.
(författare)
-
Geographic origin and migration phenology of European red admirals (Vanessa atalanta) as revealed by stable isotopes
- 2018
-
Ingår i: Movement Ecology. - : Springer Science and Business Media LLC. - 2051-3933. ; 6:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Long-distance migration has evolved multiple times in different animal taxa. For insect migrants, the complete annual migration cycle covering several thousand kilometres, may be performed by several generations, each migrating part of the distance and reproducing. Different life-cycle stages and preferred orientation may thus, be found along the migration route. For migrating red admirals (Vanessa atalanta) it has been questioned if they reproduce in the most northern part of the range. Here we present migration phenology data from a two-year time series of migrating red admirals captured at Rybachy, Kaliningrad, in the northern part of Europe investigating time for migration, life-history stage (migration, reproduction) as well as site of origin in individual butterflies. Methods: Red admirals were captured daily at a coastal site during spring, summer and autumn in 2004 and 2005. For the sampled individuals, reproductive status and fuel content were estimated by visual inspection, and hydrogen isotopes (δ 2H) were analysed in wing samples. δ 2H values was compared with samples from two nearby reference sites in Estonia and Poland. Results: Analysis of hydrogen isotopes (δ 2H) in red admiral wings showed that the spring cohort were of a southerly origin, while those caught in August or later in the autumn were from the local region or areas further to the north. All females caught during spring had developing eggs in their abdomen, but no eggs were found in late summer/autumn. There was a male-biased sex ratio during autumn and a difference in lipid content between years. When comparing the isotopic data with inland nearby locations, it was clear that the range of δ 2H values (- 181 to - 78) was wider at Rybachy as compared to the two reference sites in Estonia and Poland (- 174 to - 100). Conclusions: During spring, migratory female red admirals arrived from the south and were ready to reproduce, while the autumn passage mainly engaged local and more northern individuals carrying large fuel deposits in preparation for long-distance migration. The phenology data suggest that individuals select to migrate in favourable weather conditions and that numbers may differ between years. Future studies should focus on individual sampling at a wide range of sites to reveal differential migration strategies and timing of migration between sexes and populations of migrating butterflies.
|
|
| 12. |
- Brattström, Oskar, et al.
(författare)
-
Placing butterflies on the map - testing regional geographical resolution of three stable isotopes in Sweden using the monophagus peacock Inachis io
- 2008
-
Ingår i: Ecography. - : Wiley. - 1600-0587 .- 0906-7590. ; 31:4, s. 490-498
-
Tidskriftsartikel (refereegranskat)abstract
- Stable isotope analyses of tissues have been used to help delineate natal regions and routes of migratory animals. The foundations of such studies are isotopic gradients or differences representing geographic regions and habitat used by the organism that are retained in selected tissues. We sampled peacock butterflies Inachis io on a regional level in southern Sweden to study natural variation and the resolving power of the stable isotope method to delineate individuals from known areas on a smaller scale than has typically been used in previous studies. Hydrogen (delta D), carbon (delta C-13) and nitrogen (delta N-15) isotopes were obtained from butterflies at seven different locations in an area of 250x250 km over three years (2002-2004). We found sufficient isotopic differences on this regional scale to delineate approximate origins. Of the three isotopes, deuterium showed good discrimination between sites, carbon isotopes showed weaker differentiation, whereas nitrogen isotopes proved unsuitable for small scale studies in this region due to high and unpredictable variation. We found there was enough variation in delta D between years to prevent a general application of the technique to resolve sub-regional variation. Substantial part of this variation was probably caused by seasonal changes in delta D of precipitation. These differences produce significant variation in delta D between years in animals having short and variable tissue development times, and are difficult to estimate in natural situations. We conclude that stable isotopes are potentially powerful predictors for studies of migratory butterflies in Europe. However, without good knowledge about the sampled individuals' previous life-history, a lot of the natural environmental variation in tissue delta D cannot be controlled for. In the case of migratory species, this information is difficult to obtain, making the confidence intervals for prediction of natal areas fairly wide and probably only suitable for longer distance migration.
|
|
| 13. |
- Brattström, Oskar, et al.
(författare)
-
Understanding the migration ecology of European red admirals Vanessa atalanta using stable hydrogen isotopes
- 2010
-
Ingår i: Ecography. - : Wiley. - 1600-0587 .- 0906-7590. ; 33:4, s. 720-729
-
Tidskriftsartikel (refereegranskat)abstract
- Tracking migratory movement of small animals with variable migration patterns is difficult with standard mark-recapture methods or genetic analysis. We used stable hydrogen isotope (delta D) measurements of wings from European red admirals Vanessa atalanta to study several aspects of this species' migration. In the central part of southern Europe we found large differences in delta D values between red admirals sampled in autumn and spring supporting the hypothesis that reproduction takes place in the Mediterranean region during winter. There was also an apparent influx to southern Europe in the spring of individuals with a more southerly origin, since many samples had higher delta D values and similar to those expected from coastal areas of North Africa. We found a clear seasonal difference in the delta D values of red admirals sampled in northern Europe. Spring migrants arriving in northern Europe generally had high delta D values that indicated a southerly origin. In autumn, delta D values suggested that red admirals were mostly from regions close to the sampling sites, but throughout the sampling period there were always individuals with delta D values suggesting non-local origins. The migration pattern of this species is supposedly highly variable and plastic. delta D differences between individuals in the western part of Europe were generally small making migratory patterns difficult to interpret. However, butterflies from western Europe were apparently isolated from those from north-eastern Europe, since delta D values in the western region rarely corresponded to those of autumn migrants from the north-east. Use of delta D data for inferring butterfly migration in Europe is complex, but our study showed that this technique can be used to help uncover previously unknown aspects of red admiral migration.
|
|
| 14. |
- Jiguet, Frédéric, et al.
(författare)
-
Unravelling migration connectivity reveals unsustainable hunting of the declining ortolan bunting
- 2019
-
Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 5:5
-
Tidskriftsartikel (refereegranskat)abstract
- In France, illegal hunting of the endangered ortolan bunting Emberiza hortulana has been defended for the sake of tradition and gastronomy. Hunters argued that ortolan buntings trapped in southwest France originate from large and stable populations across the whole of Europe. Yet, the European Commission referred France to the Court of Justice of the European Union (EU) in December 2016 for infringements to legislation (IP/16/4213). To better assess the impact of hunting in France, we combined Pan-European data from archival light loggers, stable isotopes, and genetics to determine the migration strategy of the species across continents. Ortolan buntings migrating through France come from northern and western populations, which are small, fragmented and declining. Population viability modeling further revealed that harvesting in southwest France is far from sustainable and increases extinction risk. These results provide the sufficient scientific evidence for justifying the ban on ortolan harvesting in France.
|
|
| 15. |
- Linnebjerg, Jannie Fries, et al.
(författare)
-
Deciphering the structure of the West Greenland marine food web using stable isotopes (δ13C, δ15N)
- 2016
-
Ingår i: Marine Biology. - : Springer Science and Business Media LLC. - 0025-3162 .- 1432-1793. ; 163:11
-
Tidskriftsartikel (refereegranskat)abstract
- The Arctic is facing major environmental changes impacting marine biodiversity and ecosystem functioning. One way of assessing the responses of an ecosystem to these changes is to quantitatively study food web dynamics. Here, we used stable isotope (δ15N and δ13C) analyses of 39 Arctic marine species to investigate trophic relationships and isotopic niches of the West Greenland food web in 2000–2004. The lowest δ15N values were found for suspension feeding blue mussel (Mytilus edulis; 6.1 ‰) and the highest for polar bear (Ursus maritimus; 20.2 ‰). For δ13C, copepods (Calanus spp.) had the lowest values (−20.4 ‰) and snow crab (Chionoecetes opilio) the highest values (−15.8 ‰). Our results show that the three trophic enrichment factor (TEF) approaches used to quantify species trophic positions (fixed TEF of 3.8 and 3.4 ‰ or scaled TEF) did not generally affect trophic modelling and provided similar conclusions. Overall, the findings in this study are in good agreement with previous investigations of other Arctic marine ecosystems. Interestingly, we found little overlap of core isotopic niches used by the four investigated functional groups (mammals, seabirds, fish and invertebrates), except for seabirds and fish where an overlap of 24 % was found. These results provide new insights into species and functional group interactions, as well as into the food web structure and ecosystem functioning of an important Arctic region that can be used as a template to guide future modelling of carbon, energy and contaminant flow in the region.
|
|
| 16. |
- Prochazka, Petr, et al.
(författare)
-
Using stable hydrogen isotopes (delta H-2) and ring recoveries to trace natal origins in a Eurasian passerine with a migratory divide
- 2013
-
Ingår i: Journal of Avian Biology. - 0908-8857. ; 44:6, s. 541-550
-
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.
|
|
| 17. |
- Pulgarín-R, Paulo C., et al.
(författare)
-
Migratory birds as vehicles for parasite dispersal? Infection by avian haemosporidians over the year and throughout the range of a long-distance migrant
- 2019
-
Ingår i: Journal of Biogeography. - : Wiley. - 0305-0270 .- 1365-2699. ; 46:1, s. 83-96
-
Tidskriftsartikel (refereegranskat)abstract
- Aim: The role of migratory birds in the spread of parasites is poorly known, in part because migratory strategies and behaviours potentially affecting transmission are not easy to study. We investigated the dynamics of infection by blood parasites through the annual cycle of a long-distance Nearctic–Neotropical migratory songbird to examine the role of this species in dispersing parasites between continents. Location: The Americas. Taxon: Grey-cheeked Thrush (Catharus minimus, Aves, Passeriformes, Turdidae), Birds. Methods: We used molecular and microscopy screening of haemosporidian parasites (Plasmodium, Haemoproteus, and Leucocytozoon) to examine the prevalence, distribution, and diversity of lineages through the annual cycle (breeding, migration, and wintering) of the grey-cheeked thrush in North and Central America, Santa Marta mountains, the Andes, and the Amazon. We aimed to identify transmission areas, to examine the degree of sharing of haemosporidian lineages with resident birds in various areas and to assess the potential role of immunologically naïve juvenile individuals in parasite transmission. Results: Prevalence and lineage diversity of haemosporidians varied significantly over time, being higher during breeding and fall and spring migration, and declining during wintering. Grey-cheeked thrush shared few parasite lineages with tropical resident birds and slightly more lineages with other migratory and resident boreal species. We detected gametocytes in blood during spring migration stopover, but these were of lineages not found in resident tropical birds, indicating relapses of parasites transmitted elsewhere. Transmission likely occurs mostly on the breeding grounds, where juveniles and adults carried lineages restricted to closely related species of thrushes and other species of boreal birds. Main conclusions: Long-distance migratory songbirds are likely not important dispersers of blood parasites because there are ecological and evolutionary barriers to the interchange of parasites across vastly separated areas. Further work with thorough spatial and temporal sampling across other species, and considering the role of vectors, is necessary to understand the ecological and evolutionary factors explaining the distribution of parasites over broad scales.
|
|
| 18. |
- Sorensen, Marjorie C., et al.
(författare)
-
Migration distance does not predict blood parasitism in a migratory songbird
- 2019
-
Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 9:14, s. 8294-8304
-
Tidskriftsartikel (refereegranskat)abstract
- Migration can influence host–parasite dynamics in animals by increasing exposure to parasites, by reducing the energy available for immune defense, or by culling of infected individuals. These mechanisms have been demonstrated in several comparative analyses; however, few studies have investigated whether conspecific variation in migration distance may also be related to infection risk. Here, we ask whether autumn migration distance, inferred from stable hydrogen isotope analysis of summer-grown feathers (δ2Hf) in Europe, correlates with blood parasite prevalence and intensity of infection for willow warblers (Phylloscopus trochilus) wintering in Zambia. We also investigated whether infection was correlated with individual condition (assessed via corticosterone, scaled mass index, and feather quality). We found that 43% of birds were infected with Haemoproteus palloris (lineage WW1). Using generalized linear models, we found no relationship between migration distance and either Haemoproteus infection prevalence or intensity. There was spatial variation in breeding ground origins of infected versus noninfected birds, with infected birds originating from more northern sites than noninfected birds, but this difference translated into only slightly longer estimated migration distances (~214 km) for infected birds. We found no relationship between body condition indices and Haemoproteus infection prevalence or intensity. Our results do not support any of the proposed mechanisms for migration effects on host–parasite dynamics and cautiously suggest that other factors may be more important for determining individual susceptibility to disease in migratory bird species.
|
|
| 19. |
- Veen, Thor, et al.
(författare)
-
Identifying the African Wintering Grounds of Hybrid Flycatchers Using a Multi-Isotope (delta H-2, delta C-13, delta N-15) Assignment Approach
- 2014
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:5, s. e98075-
-
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.
|
|
| 20. |
- Ware, Jessica, et al.
(författare)
-
Evidence for widespread gene flow and migration in the Globe Skimmer dragonfly Pantala flavescens
- 2022
-
Ingår i: International Journal of Odonatology. - Kiel : Wachholtz Verlag. - 1388-7890 .- 2159-6719. ; 25, s. 43-55
-
Tidskriftsartikel (refereegranskat)abstract
- The global population structure and dispersal patterns of Pantala flavescens (Fabricius, 1798) are evaluated using a geographically extensive mitochondrial DNA dataset, a more limited samples of nuclear markers, wing isotopic (δ²H) data and a literature review. No spatial or temporal haplotype structure was recovered between the samples. Isotope data suggest that most samples were immigrants at the collection locations. A literature review of migration events for the species confirms regular inter-and intra-continental migrations occur (the majority reported from Asia, Africa and Australasia), with individuals and swarms dispersing thousands of kilometers over land and oceans. Migrations coincide with prevailing winds and seasonal rains, which points to a mechanism we name the “pantropical Pantala conveyor belt”, suggesting widespread gene flow is possible for an aquatic insect with excellent flying ability linked to rapid larval development.
|
|
