scholarly journals Birds as disseminators of ixodid ticks and tick-borne pathogens: note on the relevance to migratory routes

2012 ◽  
Vol 20 (2) ◽  
pp. 86-89 ◽  
Author(s):  
Sándor Hornok ◽  
Zsolt Karcza ◽  
Tibor Csörgő

Absract It has been a long studied issue, that birds are frequently infested with ixodid ticks, and consequently play a significant role in disseminating tick-borne pathogens (especially during their seasonal migration) and influence the epidemiology of relevant diseases. In connection with the first Hungarian molecular epidemiological survey on this topic the authors would like to note, that a new, ornithological aspect of similar researches may deserve future attention. Ticks removed from mid- and long-distance migratory birds and the tick-borne pathogens they may contain can be molecularly identified (i.e. with sequencing certain genes), and their sequences could be compared with others internationally available (deposited in the GenBank). This may provide clues for determining the place or country where the bird most likely acquired its tick-infestation, and thus for the probable route of seasonal migration.

2015 ◽  
Vol 282 (1819) ◽  
pp. 20151921 ◽  
Author(s):  
Kira E. Delmore ◽  
Haley L. Kenyon ◽  
Ryan R. Germain ◽  
Darren E. Irwin

Differences in seasonal migration might promote reproductive isolation and differentiation by causing populations in migratory divides to arrive on the breeding grounds at different times and/or produce hybrids that take inferior migratory routes. We examined this question by quantifying divergence in song, colour, and morphology between sister pairs of North American migratory birds. We predicted that apparent rates of phenotypic differentiation would differ between pairs that do and do not form migratory divides. Consistent with this prediction, results from mixed effects models and Ornstein–Uhlenbeck models of evolution showed different rates of divergence between these groups; surprisingly, differentiation was greater among non-divide pairs. We interpret this finding as a result of variable rates of population blending and fusion between partially diverged forms. Ancient pairs of populations that subsequently fused are now observed as a single form, whereas those that did not fuse are observable as pairs and included in our study. We propose that fusion of two populations is more likely to occur when they have similar migratory routes and little other phenotypic differentiation that would cause reproductive isolation. By contrast, pairs with migratory divides are more likely to remain reproductively isolated, even when differing little in other phenotypic traits. These findings suggest that migratory differences may be one among several isolating barriers that prevent divergent populations from fusing and thereby increase the likelihood that they will continue differentiating as distinct species.


2017 ◽  
Vol 284 (1854) ◽  
pp. 20170149 ◽  
Author(s):  
Elham Nourani ◽  
Noriyuki M. Yamaguchi ◽  
Hiroyoshi Higuchi

Migratory birds can be adversely affected by climate change as they encounter its geographically uneven impacts in various stages of their life cycle. While a wealth of research is devoted to the impacts of climate change on distribution range and phenology of migratory birds, the indirect effects of climate change on optimal migratory routes and flyways, through changes in air movements, are poorly understood. Here, we predict the influence of climate change on the migratory route of a long-distant migrant using an ensemble of correlative modelling approaches, and present and future atmospheric data obtained from a regional climate model. We show that changes in wind conditions by mid-century will result in a slight shift and reduction in the suitable areas for migration of the study species, the Oriental honey-buzzard, over a critical section of its autumn journey, followed by a complete loss of this section of the traditional route by late century. Our results highlight the need for investigating the consequences of climate change-induced disturbance in wind support for long-distance migratory birds, particularly species that depend on the wind to cross ecological barriers, and those that will be exposed to longer journeys due to future range shifts.


2021 ◽  
Vol 15 ◽  
Author(s):  
David Dreyer ◽  
Barrie Frost ◽  
Henrik Mouritsen ◽  
Adrien Lefèvre ◽  
Myles Menz ◽  
...  

Studying the routes flown by long-distance migratory insects comes with the obvious challenge that the animal’s body size and weight is comparably low. This makes it difficult to attach relatively heavy transmitters to these insects in order to monitor their migratory routes (as has been done for instance in several species of migratory birds. However, the rather delicate anatomy of insects can be advantageous for testing their capacity to orient with respect to putative compass cues during indoor experiments under controlled conditions. Almost 20 years ago, Barrie Frost and Henrik Mouritsen developed a flight simulator which enabled them to monitor the heading directions of tethered migratory Monarch butterflies, both indoors and outdoors. The design described in the original paper has been used in many follow-up studies to describe the orientation capacities of mainly diurnal lepidopteran species. Here we present a modification of this flight simulator design that enables studies of nocturnal long-distance migration in moths while allowing controlled magnetic, visual and mechanosensory stimulation. This modified flight simulator has so far been successfully used to study the sensory basis of migration in two European and one Australian migratory noctuid species.


Author(s):  
Franz Rubel ◽  
Katharina Brugger ◽  
Lidia Chitimia-Dobler ◽  
Hans Dautel ◽  
Elisabeth Meyer-Kayser ◽  
...  

AbstractAn updated and increased compilation of georeferenced tick locations in Germany is presented here. This data collection extends the dataset published some years ago by another 1448 new tick locations, 900 locations of which were digitized from literature and 548 locations are published here for the first time. This means that a total of 3492 georeferenced tick locations is now available for Germany. The tick fauna of Germany includes two species of Argasidae in the genera Argas and Carios and 19 species of Ixodidae in the genera Dermacentor, Haemaphysalis, and Ixodes, altogether 21 tick species. In addition, three species of Ixodidae in the genera Hyalomma (each spring imported by migratory birds) and Rhipicephalus (occasionally imported by dogs returning from abroad with their owners) are included in the tick atlas. Of these, the georeferenced locations of 23 tick species are depicted in maps. The occurrence of the one remaining tick species, the recently described Ixodes inopinatus, is given at the level of the federal states. The most common and widespread tick species is Ixodes ricinus, with records in all 16 federal states. With the exception of Hamburg, Dermacentor reticulatus was also found in all federal states. The occurrence of the ixodid ticks Ixodes canisuga, Ixodes frontalis, Ixodes hexagonus and I. inopinatus were documented in at least 11 federal states each. The two mentioned argasid tick species were also documented in numerous federal states, the pigeon tick Argas reflexus in 11 and the bat tick Carios vespertilionis in seven federal states. The atlas of ticks in Germany and the underlying digital dataset in the supplement can be used to improve global tick maps or to study the effects of climate change and habitat alteration on the distribution of tick species.


2011 ◽  
Vol 7 (6) ◽  
pp. 833-835 ◽  
Author(s):  
Raymond H. G. Klaassen ◽  
Thomas Alerstam ◽  
Peter Carlsson ◽  
James W. Fox ◽  
Åke Lindström

Migratory land birds perform extreme endurance flights when crossing ecological barriers, such as deserts, oceans and ice-caps. When travelling over benign areas, birds are expected to migrate by shorter flight steps, since carrying the heavy fuel loads needed for long non-stop flights comes at considerable cost. Here, we show that great snipes Gallinago media made long and fast non-stop flights (4300–6800 km in 48–96 h), not only over deserts and seas but also over wide areas of suitable habitats, which represents a previously unknown migration strategy among land birds. Furthermore, the great snipes achieved very high ground speeds (15–27 m s −1 ), which was not an effect of strong tailwind support, and we know of no other animal that travels this rapidly over such a long distance. Our results demonstrate that some migratory birds are prepared to accept extreme costs of strenuous exercise and large fuel loads, even when stopover sites are available along the route and there is little tailwind assistance. A strategy of storing a lot of energy before departure, even if migration is over benign habitats, may be advantageous owing to differential conditions of fuel deposition, predation or infection risk along the migration route.


2015 ◽  
Vol 85 (1) ◽  
pp. 3 ◽  
Author(s):  
Michelangelo Morganti

Recent climate change is altering the migratory behaviour of many bird species. An advancement in the timing of spring events and a shift in the geographical distribution have been detected for birds around the world. In particular, intra-Palearctic migratory birds have advanced arrivals in spring and shortened migratory distances by shifting northward their wintering grounds. These changes in migratory patterns are considered adaptive responses facilitating the adjustment of the life cycle to the phenological changes found in their breeding areas. However, in some cases, populations exposed to the same selective pressures do not show any appreciable adaptive change in their behaviour. Basing on the comparison of realized and non-realized adaptive changes, I propose here the formulation of a qualitative model that predicts the potential of migratory birds populations to change adaptively their migratory behaviour. The model assumes that the adaptive potential of migratory behaviour is fuelled by both genetic diversity and phenotypic plasticity. Populations of long-distance migrants are exposed to strong environmental canalization that largely eroded their phenotypic plasticity and reduced genetic variability, so that they show a very low amount of adaptive potential regarding migratory behaviour. On the contrary, partial-migrant populations have a highly varied genetic profile and are more plastic at the phenotypic level, and consequently show the highest amount of adaptive potential. Species with mainly social and mainly genetic determination of the migratory behaviour are separately treated in the model. Specific empirical models to foresee the adaptive strategies of wild bird populations that face to climate change can be derived from the general theoretical model. As example, a specific model about the shortening of migratory distances in Western European migratory bird is presented. Finally, a number of future research lines on the topic of adaptive potential of migratory behaviour are discussed, including some examples of concrete study cases. In conclusion, partial-migration emerge as the less known system and future research efforts on this topic are expected to be especially fruitful.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3201 ◽  
Author(s):  
David P.L. Toews ◽  
Kira E. Delmore ◽  
Matthew M. Osmond ◽  
Philip D. Taylor ◽  
Darren E. Irwin

Background Zones of contact between closely related taxa with divergent migratory routes, termed migratory divides, have been suggested as areas where hybrid offspring may have intermediate and inferior migratory routes, resulting in low fitness of hybrids and thereby promoting speciation. In the Rocky Mountains of Canada there is a narrow hybrid zone between Audubon’s and myrtle warblers that is likely maintained by selection against hybrids. Band recoveries and isotopic studies indicate that this hybrid zone broadly corresponds to the location of a possible migratory divide, with Audubon’s warblers migrating south-southwest and myrtle warblers migrating southeast. We tested a key prediction of the migratory divide hypothesis: that genetic background would be predictive of migratory orientation among warblers in the center of the hybrid zone. Methods We recorded fall migratory orientation of wild-caught migrating warblers in the center of the hybrid zone as measured by video-based monitoring of migratory restlessness in circular orientation chambers. We then tested whether there was a relationship between migratory orientation and genetic background, as measured using a set of species-specific diagnostic genetic markers. Results We did not detect a significant association between orientation and genetic background. There was large variation among individuals in orientation direction. Mean orientation was towards the NE, surprising for birds on fall migration, but aligned with the mountain valley in which the study took place. Conclusions Only one other study has directly analyzed migratory orientation among naturally-produced hybrids in a migratory divide. While the other study showed an association between genetic background and orientation, we did not observe such an association in yellow-rumped warblers. We discuss possible reasons, including the possibility of a lack of a strong migratory divide in this hybrid zone and/or methodological limitations that may have prevented accurate measurements of long-distance migratory orientation.


2018 ◽  
Vol 75 (3) ◽  
pp. 488-496 ◽  
Author(s):  
Graham D. Raby ◽  
Christopher S. Vandergoot ◽  
Todd A. Hayden ◽  
Matthew D. Faust ◽  
Richard T. Kraus ◽  
...  

Thermoregulation is presumed to be a widespread determinant of behaviour in fishes, but has not often been investigated as a mechanism shaping long-distance migrations. We used acoustic telemetry and animal-borne thermal loggers to test the hypothesis that seasonal migration in adult walleye (Sander vitreus) in Lake Erie is size- and (or) sex-specific and related to behavioural thermoregulation. Female walleye migrated out of the warm, shallow western basin earlier than did males and were 1.8 times more likely to be detected on acoustic receivers in the deeper and cooler eastern basin. The few fish that remained in the western basin were restricted to a smaller range of higher temperatures (≥20 °C) than those that migrated to the central and eastern basins (∼16–21 °C). However, temperature records from walleye in the central basin were nearly indistinguishable from those in the eastern basin, suggesting thermal preferences alone could not explain migration to the eastern basin. As such, our effort to understand the mechanisms that cause migratory behaviours has generated mixed evidence on the role of temperature and that factors like foraging opportunities may have synergistic roles in the migration.


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