Journal articles on the topic 'Annual migrations'
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Watts, Bryan D., Fletcher M. Smith, Chance Hines, Laura Duval, Diana J. Hamilton, Tim Keyes, Julie Paquet, et al. "The annual cycle for whimbrel populations using the Western Atlantic Flyway." PLOS ONE 16, no. 12 (December 31, 2021): e0260339. http://dx.doi.org/10.1371/journal.pone.0260339.
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Many long-distance migratory birds use habitats that are scattered across continents and confront hazards throughout the annual cycle that may be population-limiting. Identifying where and when populations spend their time is fundamental to effective management. We tracked 34 adult whimbrels (Numenius phaeopus) from two breeding populations (Mackenzie Delta and Hudson Bay) with satellite transmitters to document the structure of their annual cycles. The two populations differed in their use of migratory pathways and their seasonal schedules. Mackenzie Delta whimbrels made long (22,800 km) loop migrations with different autumn and spring routes. Hudson Bay whimbrels made shorter (17,500 km) and more direct migrations along the same route during autumn and spring. The two populations overlap on the winter grounds and within one spring staging area. Mackenzie Delta whimbrels left the breeding ground, arrived on winter grounds, left winter grounds and arrived on spring staging areas earlier compared to whimbrels from Hudson Bay. For both populations, migration speed was significantly higher during spring compared to autumn migration. Faster migration was achieved by having fewer and shorter stopovers en route. We identified five migratory staging areas including four that were used during autumn and two that were used during spring. Whimbrels tracked for multiple years had high (98%) fidelity to staging areas. We documented dozens of locations where birds stopped for short periods along nearly all migration routes. The consistent use of very few staging areas suggests that these areas are integral to the annual cycle of both populations and have high conservation value.
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Zhitin, Ruslan, and Alexey Topiliskiy. "Social and economic effects of labor migrations of the Poles in the German empire in the late XIX – early XX century." Przegląd Wschodnioeuropejski 9, no. 1 (June 1, 2018): 21–29. http://dx.doi.org/10.31648/pw.3263.
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The article focuses on the problem of labor migrations of the peasant population of Vistula Land of Russia to the German Empire at the turn of the XIX and ХХ century. The subject of the study are the causes of migration, the situation of Polish workers abroad, the specifics and main spheres of hiring workers, the social and economic effects of the movement. The urgency of the work is determined by inadequate historiographic attention to the factor of the annual retreat of tens of thousands of Poles abroad. The article uses the civilizational approach, the principle of historicism, the ideas of the French school “Annals”. The conclusions obtained by the authors of the article testify to the special significance of migrations not only for the inhabitants of the Polish province, but also for the entire German landlord economy. Migration compensated for the labor shortage in Germany’s agrarian sector, ensuring rapid growth in production in the states. The experience of migration stimulated the economic initiative of Poles, increased their standard of living, affected the size of peasant land ownership in the Vistula Land.
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Daversa, David R., Camino Monsalve-Carcaño, Luis M. Carrascal, and Jaime Bosch. "Seasonal migrations, body temperature fluctuations, and infection dynamics in adult amphibians." PeerJ 6 (May 8, 2018): e4698. http://dx.doi.org/10.7717/peerj.4698.
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Risks of parasitism vary over time, with infection prevalence often fluctuating with seasonal changes in the annual cycle. Identifying the biological mechanisms underlying seasonality in infection can enable better prediction and prevention of future infection peaks. Obtaining longitudinal data on individual infections and traits across seasons throughout the annual cycle is perhaps the most effective means of achieving this aim, yet few studies have obtained such information for wildlife. Here, we tracked spiny common toads (Bufo spinosus) within and across annual cycles to assess seasonal variation in movement, body temperatures and infection from the fungal parasite, Batrachochytrium dendrobatidis (Bd). Across annual cycles, toads did not consistently sustain infections but instead gained and lost infections from year to year. Radio-tracking showed that infected toads lose infections during post-breeding migrations, and no toads contracted infection following migration, which may be one explanation for the inter-annual variability in Bd infections. We also found pronounced seasonal variation in toad body temperatures. Body temperatures approached 0 °C during winter hibernation but remained largely within the thermal tolerance range of Bd. These findings provide direct documentation of migratory recovery (i.e., loss of infection during migration) and escape in a wild population. The body temperature reductions that we observed during hibernation warrant further consideration into the role that this period plays in seasonal Bd dynamics.
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Åkesson, Susanne, Mihaela Ilieva, Julia Karagicheva, Eldar Rakhimberdiev, Barbara Tomotani, and Barbara Helm. "Timing avian long-distance migration: from internal clock mechanisms to global flights." Philosophical Transactions of the Royal Society B: Biological Sciences 372, no. 1734 (October 9, 2017): 20160252. http://dx.doi.org/10.1098/rstb.2016.0252.
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Migratory birds regularly perform impressive long-distance flights, which are timed relative to the anticipated environmental resources at destination areas that can be several thousand kilometres away. Timely migration requires diverse strategies and adaptations that involve an intricate interplay between internal clock mechanisms and environmental conditions across the annual cycle. Here we review what challenges birds face during long migrations to keep track of time as they exploit geographically distant resources that may vary in availability and predictability, and summarize the clock mechanisms that enable them to succeed. We examine the following challenges: departing in time for spring and autumn migration, in anticipation of future environmental conditions; using clocks on the move, for example for orientation, navigation and stopover; strategies of adhering to, or adjusting, the time programme while fitting their activities into an annual cycle; and keeping pace with a world of rapidly changing environments. We then elaborate these themes by case studies representing long-distance migrating birds with different annual movement patterns and associated adaptations of their circannual programmes. We discuss the current knowledge on how endogenous migration programmes interact with external information across the annual cycle, how components of annual cycle programmes encode topography and range expansions, and how fitness may be affected when mismatches between timing and environmental conditions occur. Lastly, we outline open questions and propose future research directions. This article is part of the themed issue ‘Wild clocks: integrating chronobiology and ecology to understand timekeeping in free-living animals’.
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Boyle, W. A. "Does food abundance explain altitudinal migration in a tropical frugivorous bird?" Canadian Journal of Zoology 88, no. 2 (February 2010): 204–13. http://dx.doi.org/10.1139/z09-133.
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Many animals undergo annual migrations. These movements are well studied at proximate levels, but their fundamental causes are poorly understood. Among tropical frugivorous birds, annual migration is thought to have evolved in the context of exploiting reciprocal peaks in fruit abundance among locations and seasons, yet previous tests of this hypothesis have yielded equivocal results. In this paper, I tested whether protein and (or) fruit limitation explain both uphill and downhill migratory movements in a tropical frugivorous bird, the White-ruffed Manakin ( Corapipo altera Hellmayer, 1906). While White-ruffed Manakins likely migrate uphill to exploit peaks in fruit abundance, I found no evidence that elevational differences in fruit abundance explain the downhill portion of the migratory cycle. This result challenges long-standing ideas regarding the causes of altitudinal migration because it implies that birds seeking to maximize fruit intake should remain sedentary at higher elevations. Data are also inconsistent with the hypothesis that White-ruffed Manakins migrate (either uphill or downhill) to exploit arthropod prey. Future studies should consider how variation in weather, predators, or parasites could help explain altitudinal migrations of birds from breeding areas to nonbreeding areas.
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Linthicum, Janet, Ronald E. Jackman, Brian C. Latta, Jeannine Koshear, and Michael Smith. "ANNUAL MIGRATIONS OF BALD EAGLES TO AND FROM CALIFORNIA." Journal of Raptor Research 41, no. 2 (June 2007): 106–12. http://dx.doi.org/10.3356/0892-1016(2007)41[106:amobet]2.0.co;2.
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Gabaccia, Donna, Leslie Page Moch, Marcelo J. Borges, Franca Iacovetta, Madeline Y. Hsu, Patrick Manning, Leo Lucassen, and Dirk Hoerder. "Cultures in Contact." International Review of Social History 49, no. 3 (November 29, 2004): 475–515. http://dx.doi.org/10.1017/s0020859004001762.
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In 2002, Dirk Hoerder published his magnum opus, Cultures in Contact: World Migrations in the Second Millennium (Durham, NC, 2002). In this book, Hoerder describes and analyses, with an unusual breadth of scope, the origins, causes, and extent of human migration around the globe from the eleventh century onward to the present day, paying particular attention to the impact migrations have had in the receiving countries and the cultural interactions they have triggered. At the 28th Annual Meeting of the American Social Science History Association, organized in November 2003 in Baltimore, Dirk Hoerder's book was the winner of the Allan Sharlin Memorial Award for the best book in social science history. In this review symposium, seven migration scholars from differing national and cultural backgrounds give their comments on Hoerder's book, with a concluding response by Dirk Hoerder.
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Schaeffer, Peter V., and Mulugeta S. Kahsai. "A Theoretical Note on the Relationship between Documented and Undocumented Migration." International Journal of Population Research 2011 (August 4, 2011): 1–7. http://dx.doi.org/10.1155/2011/873967.
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Undocumented migration is a (inferior) substitute to documented migration. Hence, policies affecting documented migration also affect undocumented migration. This paper explores this relationship from a theoretical perspective. The implications of this exploration are that lax enforcement of visa rules and national borders, combined with a very long waiting line (small annual quotas) for immigrant visas, can make illegal immigration a preferred option over legal immigration or, more generally, that for policy purposes all types of migrations should be regarded as interdependent. Therefore, policies aimed solely at, say, undocumented immigration will generally be less effective than an integrated policy approach.
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Wong, JB, S. Lisovski, RT Alisauskas, W. English, MA Giroux, AL Harrison, D. Kellett, et al. "Arctic terns from circumpolar breeding colonies share common migratory routes." Marine Ecology Progress Series 671 (August 5, 2021): 191–206. http://dx.doi.org/10.3354/meps13779.
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The Arctic tern is an iconic seabird, famous for its annual migrations between the Arctic and the Antarctic. Its wide geographical range has impeded knowledge of potential population bottlenecks during its annual bi-hemispheric movements. Although Arctic terns breed in the Pacific, Atlantic, and Arctic coasts of North America, few tracking studies have been conducted on North American Arctic terns, and none in Canada, which represents a significant proportion of their circumpolar breeding range. Using light-level geolocators, we tracked 53 Arctic terns from 5 breeding colonies across a wide latitudinal and longitudinal range within North America. We compared the routes taken by birds in our study and migration timing to those previously tracked from Greenland, Iceland, The Netherlands, Sweden, Norway, Maine (USA), and S. Alaska (USA). Most Arctic terns tracked globally used one of 3 southbound migration routes: (1) Atlantic West Africa; (2) Atlantic Brazil; and (3) Pacific coastal, and one of 2 northbound migration routes: (1) Mid-ocean Atlantic and (2) Mid-ocean Pacific. Some other trans-equatorial seabirds also used these migration routes, suggesting that Arctic tern routes may be important for other species. The migration timing for southbound and northbound migrations was generally different between tracked tern colonies worldwide but generally fell within a 1-2 mo window. Our research suggests that conservation management of Arctic terns during their migration should dynamically adapt with the times of the year that terns use parts of their route. Future identification of common multi-species seabird flyways could aid the international negotiations required to conserve pelagic seabirds such as Arctic terns.
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Buehler, Deborah M., and Theunis Piersma. "Travelling on a budget: predictions and ecological evidence for bottlenecks in the annual cycle of long-distance migrants." Philosophical Transactions of the Royal Society B: Biological Sciences 363, no. 1490 (July 18, 2007): 247–66. http://dx.doi.org/10.1098/rstb.2007.2138.
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Long-distance migration, and the study of the migrants who undertake these journeys, has fascinated generations of biologists. However, many aspects of the annual cycles of these migrants remain a mystery as do many of the driving forces behind the evolution and maintenance of the migrations themselves. In this article we discuss nutritional, energetic, temporal and disease - risk bottlenecks in the annual cycle of long-distance migrants, taking a sandpiper, the red knot Calidris canutus , as a focal species. Red knots have six recognized subspecies each with different migratory routes, well-known patterns of connectivity and contrasting annual cycles. The diversity of red knot annual cycles allows us to discuss the existence and the effects of bottlenecks in a comparative framework. We examine the evidence for bottlenecks focusing on the quality of breeding plumage and the timing of moult as indicators in the six subspecies. In terms of breeding plumage coloration, quality and timing of prealternate body moult (from non-breeding into breeding plumage), the longest migrating knot subspecies, Calidris canutus rogersi and Calidris canutus rufa , show the greatest impact of bottlenecking. The same is true in terms of prebasic body moult (from breeding into non-breeding plumage) which in case of both C. c. rogersi and C. c. rufa overlaps with southward migration and may even commence in the breeding grounds. To close our discussion of bottlenecks in long-distance migrants, we make predictions about how migrants might be impacted via physiological ‘trade-offs’ throughout the annual cycle, using investment in immune function as an example. We also predict how bottlenecks may affect the distribution of mortality throughout the annual cycle. We hope that this framework will be applicable to other species and types of migrants, thus expanding the comparative database for the future evaluation of seasonal selection pressures and the evolution of annual cycles in long-distance migrants. Furthermore, we hope that this synthesis of recent advancements in the knowledge of red knot annual cycles will prove useful in the ongoing attempts to model annual cycles in migratory birds.
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Bell, Donovan A., Ryan P. Kovach, Scott C. Vulstek, John E. Joyce, and David A. Tallmon. "Climate-induced trends in predator–prey synchrony differ across life-history stages of an anadromous salmonid." Canadian Journal of Fisheries and Aquatic Sciences 74, no. 9 (September 2017): 1431–38. http://dx.doi.org/10.1139/cjfas-2016-0309.
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Differential climate-induced shifts in phenology can create mismatches between predators and prey, but few studies have examined predator–prey mismatch across multiple life-history stages. We used long-term data from a warming stream with shifting salmonid migration timings to quantify intra-annual migration synchrony between predatory Dolly Varden (Salvelinus malma) and Pacific salmon prey and examined how predator–prey synchrony has been influenced by climate change. We demonstrate that Dolly Varden have become increasingly mismatched with spring downstream migrations of abundant pink salmon (Oncorhynchus gorbuscha) juveniles. However, Dolly Varden have remained matched with fall upstream migrations of spawning Pacific salmon, including coho (Oncorhynchus kisutch), sockeye (Oncorhynchus nerka), and pink salmon. Downstream predator–prey migration synchrony decreased over time and with higher temperatures, particularly with pink salmon. In contrast, upstream migration synchrony was temporally stable and increased with rising temperatures. Differing trends in Dolly Varden predator–prey synchrony may be explained by the direct use of salmon to cue upstream migration, but not downstream migration. Overall, we show that climate change can have differing impacts on predator–prey synchrony across life-history stages.
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Del Raye, Gen, Salvador J. Jorgensen, Kira Krumhansl, Juan M. Ezcurra, and Barbara A. Block. "Travelling light: white sharks ( Carcharodon carcharias ) rely on body lipid stores to power ocean-basin scale migration." Proceedings of the Royal Society B: Biological Sciences 280, no. 1766 (September 7, 2013): 20130836. http://dx.doi.org/10.1098/rspb.2013.0836.
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Many species undertake long-distance annual migrations between foraging and reproductive areas. Such migrants depend on the efficient packaging, storage and utilization of energy to succeed. A diverse assemblage of organisms accomplishes this through the use of lipid reserves; yet, it remains unclear whether the migrations of elasmobranchs, which include the largest gill breathers on Earth, depend on such a mechanism. We examine depth records from pop-up satellite archival tags to discern changes in buoyancy as a proxy for energy storage in Eastern Pacific white sharks, and assess whether lipid depletion fuels long-distance (approx. 4000 km) migrations. We develop new algorithms to assess body condition, buoyancy and drift rate during drift dives and validate the techniques using a captive white shark. In the wild, we document a consistent increase in drift rate over the course of all migrations, indicating a decrease in buoyancy caused by the depletion of lipid reserves. These results comprise, to our knowledge, the first assessment of energy storage and budgeting in migrating sharks. The methods provide a basis for further insights into using electronic tags to reveal the energetic strategies of a wide range of elasmobranchs.
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Bezverbny, Vadim A., and Nikolai Y. Mikryukov. "FEATURES OF INTER-REGIONAL MIGRATION IN THE RUSSIAN FEDERATION IN 2017–2019." SCIENTIFIC REVIEW. SERIES 2. HUMAN SCIENCES, no. 6 (2021): 45–65. http://dx.doi.org/10.26653/2076-4685-2021-6-05.
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In the previous article of authors [4], the main regions-attractors in Russia were identified: the Moscow metropolitan agglomeration, the St. Petersburg agglomeration, the Black Sea regions of the South of Russia, Krasnodar Territory, the Republic of Crimea, the city of Sevastopol, the Republic of Adygea, the Kaliningrad region in the Baltic. Most of the interregional migration flow is directed to these regions. The general picture of interregional migrations is more complicated and is not limited to the main regions as attractors. It is advisable to consider more fully the flows of interregional migrations in Russia. To analyze interregional migration, we used Rosstat data for 2017–2019. The indicators were taken in total for 2017–2019. to exclude annual random fluctuations, to more accurately identify the nature of migration. We excluded the Republic of Ingushetia from consideration due to the complexities and peculiarities of statistical recording of the migration loss of the population in this region. The study was carried out on the basis of approaches to regional analysis of demographic processes, which were developed by scientists-demographers and economists in various scientific centers of Russia, including Rybakovsky O.L., Borisova L.M., Chernyshev K.A., Mishchuk S.N., Khilazhevа G.F., Ryazantsev S.V.
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Selstam, Gunnar, Jan Sondell, and Peter Olsson. "Wintering area and migration routes for Ortolan Buntings Emberiza hortulana from Sweden determined with light-loggers." Ornis Svecica 25, no. 1–2 (April 1, 2015): 3–14. http://dx.doi.org/10.34080/os.v25.19599.
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The decrease of Ortolan Bunting Emberiza hortulana in Western Europe over the last five decades has caused serious concern for the survival of this species in Sweden. In order to find out the migration routes and wintering location, we equipped several males with geologgers. Our data show annual cycles of migrations routes, wintering grounds and time schedules for seven re-trapped birds. The wintering area in West Africa is savannah woodland in a mountainous landscape in Mali and Guinea. The migration routes follow more or less the great circle between the breeding and wintering areas. Most birds were likely to have passed the well-known Ortolan catching area in les Landes south of Bordeaux in France during autumn migration.
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Brooks, George C., Jennifer A. Smith, Thomas A. Gorman, and Carola A. Haas. "Discerning the Environmental Drivers of Annual Migrations in an Endangered Amphibian." Copeia 107, no. 2 (May 16, 2019): 270. http://dx.doi.org/10.1643/ch-18-068.
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Hallworth, Michael T., Peter P. Marra, Kent P. McFarland, Sara Zahendra, and Colin E. Studds. "Tracking dragons: stable isotopes reveal the annual cycle of a long-distance migratory insect." Biology Letters 14, no. 12 (December 2018): 20180741. http://dx.doi.org/10.1098/rsbl.2018.0741.
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Insect migration is globally ubiquitous and can involve continental-scale movements and complex life histories. Apart from select species of migratory moths and butterflies, little is known about the structure of the annual cycle for migratory insects. Using stable-hydrogen isotope analysis of 852 wing samples from eight countries spanning 140 years, combined with 21 years of citizen science data, we determined the full annual cycle of a large migratory dragonfly, the common green darner ( Anax junius ). We demonstrate that darners undertake complex long-distance annual migrations governed largely by temperature that involve at least three generations. In spring, the first generation makes a long-distance northbound movement (further than 650 km) from southern to northern range limits, lays eggs and dies. A second generation emerges and returns south (further than 680 km), where they lay eggs and die. Finally, a third resident generation emerges, reproducing locally and giving rise to the cohort that migrates north the following spring. Since migration timing and nymph development are highly dependent on temperature, continued climate change could lead to fundamental changes in the biology for this and similar migratory insects.
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Jensen, Arne Johan, Bengt Finstad, and Peder Fiske. "The cost of anadromy: marine and freshwater mortality rates in anadromous Arctic char and brown trout in the Arctic region of Norway." Canadian Journal of Fisheries and Aquatic Sciences 76, no. 12 (December 2019): 2408–17. http://dx.doi.org/10.1139/cjfas-2018-0428.
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It is hypothesized that in diadromous fish, migrations may occur because of differences in the availability of food in marine and freshwater habitats. The benefits of migration to sea may be increased growth opportunities and reproductive output, while the costs may be increased mortality and increased energy use. Here we examine mortality rates of anadromous Arctic char (Salvelinus alpinus) and brown trout (Salmo trutta) in fresh water and at sea over a 25-year period to test these hypotheses. Daily mortality rates were 5–15 times higher at sea than in fresh water, with highest rates for first-time migrants, inferring a clear trade-off between increased mass gain and mortality risk during the sea migration. Descending smolts were caught in a trap at the outlet of the river, individually tagged, and thereafter recorded each time they passed through the trap on their annual migration between the river and the sea. Brown trout females seemed to benefit to a higher degree from migrating to sea than did female Arctic char, probably because of the higher growth rate at sea, and hence higher reproductive output.
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Lok, Tamar, Otto Overdijk, and Theunis Piersma. "The cost of migration: spoonbills suffer higher mortality during trans-Saharan spring migrations only." Biology Letters 11, no. 1 (January 2015): 20140944. http://dx.doi.org/10.1098/rsbl.2014.0944.
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Explanations for the wide variety of seasonal migration patterns of animals all carry the assumption that migration is costly and that this cost increases with migration distance. Although in some studies, the relationships between migration distance and breeding success or annual survival are established, none has investigated whether mortality during the actual migration increases with migration distance. Here, we compared seasonal survival between Eurasian spoonbills ( Platalea leucorodia leucorodia ) that breed in The Netherlands and migrate different distances ( ca 1000, 2000 and 4500 km) to winter in France, Iberia and Mauritania, respectively. On the basis of resightings of individually marked birds throughout the year between 2005 and 2012, we show that summer, autumn and winter survival were very high and independent of migration distance, whereas mortality during spring migration was much higher (18%) for the birds that wintered in Mauritania, compared with those flying only as far as France (5%) or Iberia (6%). As such, this study is the first to show empirical evidence for increased mortality during some long migrations, likely driven by the presence of a physical barrier (the Sahara desert) in combination with suboptimal fuelling and unfavourable weather conditions en route .
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Ennis, G. P., R. G. Hooper, and D. M. Taylor. "Changes in the Composition of Snow Crab (Chionoecetes opilio) Participating in the Annual Breeding Migration in Bonne Bay, Newfoundland." Canadian Journal of Fisheries and Aquatic Sciences 47, no. 11 (November 1, 1990): 2242–49. http://dx.doi.org/10.1139/f90-249.
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Sexually-paired snow crabs (Chionoecetes opilio) participating in an annual spring breeding migration to shallow water in Bonne Bay, Newfoundland were collected by SCUBA divers from 1984 to 1989. In 1984 the breeding pairs were composed mainly of relatively large, old-shell animals of both sexes, but by 1988 much smaller animals, most of which were new-shell, dominated the migration. Evidence from research fishing indicates that these changes are related to a rapid decline in what was characteristically a virgin population in 1984 and a coinciding strong pulse of recruitment into the breeding component of the population. A very high incidence of small, subcommercial males participating in the 1988 and 1989 breeding migrations demonstrates a capacity for maintaining a high level of reproductive potential in a snow crab population despite high exploitation rates on larger animals in the male-only fishery for this species. The strong recruitment pulse which occurred in Bonne Bay as the virgin population declined after 1984 also indicates a capacity for enhanced annual production within a snow crab population when exploitation rates are high.
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Ingram, Evan Corey, and Douglas L. Peterson. "Annual Spawning Migrations of Adult Atlantic Sturgeon in the Altamaha River, Georgia." Marine and Coastal Fisheries 8, no. 1 (January 2016): 595–606. http://dx.doi.org/10.1080/19425120.2016.1243599.
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Hupp, Jerry W., Joel A. Schmutz, and Craig R. Ely. "The Annual Migration Cycle of Emperor Geese in Western Alaska." ARCTIC 61, no. 1 (March 1, 2009): 23. http://dx.doi.org/10.14430/arctic4.
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Most emperor geese (Chen canagica) nest in a narrow coastal region of the Yukon-Kuskokwim Delta (YKD) in western Alaska, but their winter distribution extends more than 3000 km from Kodiak Island, Alaska, to the Commander Islands, Russia. We marked 53 adult female emperor geese with satellite transmitters on the YKD in 1999, 2002, and 2003 to examine whether chronology of migration or use of seasonal habitats differed among birds that wintered in different regions. Females that migrated relatively short distances (650–1010 km) between the YKD and winter sites on the south side of the Alaska Peninsula bypassed autumn staging areas on the Bering Sea coast of the Alaska Peninsula or used them for shorter periods (mean = 57 days) than birds that made longer migrations (1600–2640 km) to the western Aleutian Islands (mean = 97 days). Alaska Peninsula migrants spent more days at winter sites (mean = 172 days, 95% CI: 129–214 days) than western Aleutian Island migrants (mean = 91 days, 95% CI: 83–99 days). Birds that migrated 930–1610 km to the eastern Aleutian Islands spent intermediate intervals at fall staging (mean = 77 days) and wintering areas (mean = 108 days, 95% CI: 95–119 days). Return dates to the YKD did not differ among birds that wintered in different regions. Coastal staging areas on the Alaska Peninsula may be especially important in autumn to prepare Aleutian migrants physiologically for long-distance migration to winter sites, and in spring to enable emperor geese that migrate different distances to reach comparable levels of condition before nesting.
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Hu, Gao, Constanti Stefanescu, Tom H. Oliver, David B. Roy, Tom Brereton, Chris Van Swaay, Don R. Reynolds, and Jason W. Chapman. "Environmental drivers of annual population fluctuations in a trans-Saharan insect migrant." Proceedings of the National Academy of Sciences 118, no. 26 (June 21, 2021): e2102762118. http://dx.doi.org/10.1073/pnas.2102762118.
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Many latitudinal insect migrants including agricultural pests, disease vectors, and beneficial species show huge fluctuations in the year-to-year abundance of spring immigrants reaching temperate zones. It is widely believed that this variation is driven by climatic conditions in the winter-breeding regions, but evidence is lacking. We identified the environmental drivers of the annual population dynamics of a cosmopolitan migrant butterfly (the painted lady Vanessa cardui) using a combination of long-term monitoring and climate and atmospheric data within the western part of its Afro-Palearctic migratory range. Our population models show that a combination of high winter NDVI (normalized difference vegetation index) in the Savanna/Sahel of sub-Saharan Africa, high spring NDVI in the Maghreb of North Africa, and frequent favorably directed tailwinds during migration periods are the three most important drivers of the size of the immigration to western Europe, while our atmospheric trajectory simulations demonstrate regular opportunities for wind-borne trans-Saharan movements. The effects of sub-Saharan vegetative productivity and wind conditions confirm that painted lady populations on either side of the Sahara are linked by regular mass migrations, making this the longest annual insect migration circuit so far known. Our results provide a quantification of the environmental drivers of large annual population fluctuations of an insect migrant and hold much promise for predicting invasions of migrant insect pests, disease vectors, and beneficial species.
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Sedinger, James S., Nathan D. Chelgren, Mark S. Lindberg, Tim Obritchkewitch, Morgan T. Kirk, Philip Martin, Betty A. Anderson, and David H. Ward. "Life-History Implications of Large-Scale Spatial Variation in Adult Survival of Black Brant (Branta Bernicla Nigricans)." Auk 119, no. 2 (April 1, 2002): 510–15. http://dx.doi.org/10.1093/auk/119.2.510.
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Abstract We used capture–recapture methods to estimate adult survival rates for adult female Black Brant (Branta bernicla nigricans; hereafter “brant”) from three colonies in Alaska, two on the Yukon-Kuskokwim Delta, and one on Alaska's Arctic coast. Costs of migration and reproductive effort varied among those colonies, enabling us to examine variation in survival in relation to variation in these other variables. We used the Barker model in program MARK to estimate true annual survival for brant from the three colonies. Models allowing for spatial variation in survival were among the most parsimonious models but were indistinguishable from a model with no spatial variation. Point estimates of annual survival were slightly higher for brant from the Arctic (0.90 ± 0.036) than for brant from either Tutakoke River (0.85 ± 0.004) or Kokechik Bay (0.86 ± 0.011). Thus, our survival estimates do not support a hypothesis that the cost of longer migrations or harvest experienced by brant from the Arctic reduced their annual survival relative to brant from the Yukon-Kuskokwim Delta. Spatial variation in survival provides weak support for life-history theory because brant from the region with lower reproductive investment had slightly higher survival.
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Nielsen, Julie K., and Andrew C. Seitz. "Interannual site fidelity of Pacific halibut: potential utility of protected areas for management of a migratory demersal fish." ICES Journal of Marine Science 74, no. 8 (March 28, 2017): 2120–34. http://dx.doi.org/10.1093/icesjms/fsx040.
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Abstract Pacific halibut is a large-bodied demersal fish species known to undertake large-scale winter spawning migrations. We characterized annual movement patterns of Pacific halibut relative to a Marine Protected Area (MPA) in Glacier Bay National Park, Alaska using electronic tags. In the summer of 2013, we deployed 25 Pop-up Satellite Archival Tags (PSATs) on halibut to determine seasonal movement patterns, where residency within the MPA was inferred by comparing PSAT depth and temperature records to stationary archival tag data and oceanographic survey data. To characterize within-summer movement patterns, 15 halibut tagged with PSATs were double-tagged with acoustic transmitters and actively tracked during the summers of 2013 and 2014. Home range behaviour and interannual site fidelity at spatial scales <5 km were observed for the majority of tagged fish. A small proportion (6/21 fish with PSAT data) departed the MPA on winter migrations during December 2013. A majority (4/6) of migratory fish returned to the MPA after an average of 57 d (s.d. 22 d) spent outside of the MPA. Migration timing generally coincided with existing winter commercial fishery closures. The annual movement patterns of tagged halibut relative to MPA boundaries and winter commercial fisheries closures suggest that the Glacier Bay MPA could serve as a year-round refuge from commercial harvest for both residential and migratory halibut. If halibut behaviour is similar in other areas, protected areas may provide some utility for management despite the migratory nature of halibut.
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Mehner, Thomas. "Partial diel vertical migration of sympatric vendace (Coregonus albula) and Fontane cisco (Coregonus fontanae) is driven by density dependence." Canadian Journal of Fisheries and Aquatic Sciences 72, no. 1 (January 2015): 116–24. http://dx.doi.org/10.1139/cjfas-2014-0009.
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Recent studies have indicated that in fish populations performing diel vertical migrations (DVM), some individuals do not migrate but reflect a resident phenotype, a pattern named as partial DVM. I present data on fish densities and the proportion of residents in Lake Stechlin (Germany) as obtained by annual midwater trawling over four discrete depths during nighttime over 8 years. The lake is inhabited by the sympatric vendace (Coregonus albula) and Fontane cisco (Coregonus fontanae). The proportion of vendace residents increased with the density of vendace, whereas the proportion of Fontane cisco residents declined with increasing density, indicating that density plays a role in the migration patterns for both species, but in opposite directions. There were almost no differences in mean size, size-frequency distributions, or Fulton condition factor between resident or migrant parts of the populations in both species. However, the proportion of dry mass in wet mass, which indicates individual nutritional status, had a tendency to be lower in migrants than in residents in both species in the years 2011, 2012, and 2013. These data suggest that density dependence may be an important factor that modifies the proportion of residents in vertically migrating fish populations. In contrast, length-dependent predation vulnerability or systematic individual differences in nutritional status were not strongly supported as potential predictors of the proportion of residents. It needs to be discussed whether partial DVM is conceptually similar to partial seasonal migrations of fish, or whether DVM reflects variants of the ideal free distribution, which are inherently density-dependent.
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Patchett, Robert, Alexander N. G. Kirschel, Joanna Robins King, Patrick Styles, and Will Cresswell. "Age-related changes in migratory behaviour within the first annual cycle of a passerine bird." PLOS ONE 17, no. 10 (October 19, 2022): e0273686. http://dx.doi.org/10.1371/journal.pone.0273686.
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First time migrants (juveniles hereafter) of many species migrate without specific knowledge of non-breeding locations, but experience may aid adults in timing and route decisions because they can migrate more efficiently to their previous non-breeding sites. Consequently, we expect a transition to more efficient migratory behaviour with age, but when and how this happens is little known. We used light-level geolocator data from Cyprus wheatears Oenanthe cypriaca to compare migration timing and route directness between juveniles and adults, and repeatability of their timing and non-breeding locations. We predicted that juveniles would depart and arrive later than adults for both autumn and spring migration; that duration of migration would be greater for juveniles; that routes taken by juveniles would be less direct than those for adults; and that autumn and spring departure timing, and non-breeding locations, would be more repeatable for adults between two years than for juveniles between their first and subsequent migration. We found that juveniles departed significantly later than adults in autumn but there was no difference in arrival timing, and although spring departure timings did not differ, juveniles arrived on the breeding grounds later than adults. Nevertheless, we found no significant age-related difference in the duration of migration in autumn or spring. Yet, juvenile migrations were less direct than those of adults in autumn, but not spring. We found evidence that spring departure timing and non-breeding locations were repeatable for adults but not juveniles. Our findings show that age-related changes in migratory behaviour begin to occur during the first annual cycle demonstrating the potential for early adaptation to environmental variability within an individual’s life.
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PEDRANA, JULIETA, KLEMENS PÜTZ, LUCÍA BERNAD, SEBASTIÁN MUÑOZ, ANTONELLA GOROSÁBEL, GABRIEL CASTRESANA, ALEJANDRO LEISS, and JUAN PABLO SECO PON. "Spatial and temporal variation in the migration of Ruddy-headed Goose in southern South America using satellite tagging." Bird Conservation International 30, no. 4 (April 30, 2020): 634–48. http://dx.doi.org/10.1017/s0959270920000143.
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SummaryRuddy-headed Goose Chloephaga rubidiceps is the smallest of the five South American sheldgeese and has two separate populations: one sedentary, which resides in the Malvinas/Falkland Islands and one migratory that overwinters mainly in the Pampas region, Argentina and breeds in Southern Patagonia. The Ruddy-headed Goose’s continental population has decreased considerably, and recent estimates indicated that the population size is less than 800 individuals. In Argentina and Chile, this population is categorised as endangered. Understanding migration across vast landscapes is essential for the identification of factors affecting the survival of this endangered population and for the application of effective conservation measures. We aim to provide the first documentation of the complete migration cycle of Ruddy-headed Goose, and to analyse their annual migration in detail, including identification of stop-over, breeding and wintering sites, and to compare migration timing during spring and autumn migration. Adults were captured in the southern Pampas and equipped with solar satellite transmitters in 2015 and 2016. We analysed the influence of season (spring vs autumn migration) on the number and duration of stop-overs, distance travelled and overall migration speed using Generalized Linear Mixed Models. Our results showed that tracked geese used the eastern Patagonian route to reach their breeding grounds and take the same route after breeding. Spring migration was significantly faster than autumn migration, at least based on the number of days spent in their stop-overs. Stop-overs were closer to the final destination, either during spring and autumn migrations, though some of them were not used during subsequent migrations. Our migration cartography for Ruddy-headed Geese, together with the timing and location data, should be used to improve conservation efforts directed at this species and might contribute to the modification of the current status of ‘Least Concern’ under the IUCN criteria.
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Min, Xiao, Zijing Gao, Yuanfeng Lin, and Chang-Hu Lu. "Annual Long-Distance Migration Strategies and Home Range of Chinese Sparrowhawk (Accipiter soloensis) from South China." Animals 11, no. 8 (July 29, 2021): 2237. http://dx.doi.org/10.3390/ani11082237.
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From 2018 to 2019, two Chinese Sparrowhawks (Bird 01, male; Bird 02, female), Accipiter soloensis, were captured and fitted with Global Positioning System (GPS) loggers in order to identify summering and wintering sites, migration routes, and stop-over sites. The Chinese Sparrowhawks were first fitted with backpack solar GPS satellite trackers in China in order to explore their migration routes. The two Chinese Sparrowhawks successfully completed their migration from southern China, through Nanning city of Guangxi province, China, to Vietnam, Laos, Myanmar, Thailand, Malaysia, and Singapore and finally arriving in Indonesia, where they stayed until the March of the following year. They then returned to China along the original route, arriving in Changsha city, Hunan province, China. The two individuals traveled more than 4000–5000 km. For the first time, telemetry data demonstrate, the linkages between their Indonesia wintering sites, their stop-over sites in Southeast Asia, and their breeding/summering sites near south Yangtze River in the south-central part of China. During this long-distance migration, 2653 bird satellite sites were received. The autumn migration durations for the two Chinese Sparrowhawks were 84 days and 50 days, respectively, compared to 83 days and 49 days in spring. The median stop-over duration was 12.7 and 9.3 days, respectively and the median speed of travel was 74.2 km/day during the autumn migration and 73.9 km/day during the spring migration. Furthermore, two and one stop-over sites and one and three stop-over sites were used during the autumn and spring migrations of Chinese Sparrowhawks 01 and 02, respectively. The Chinese Sparrowhawks migrated long distances and used stop-over sites during their migration. Based on the home range analysis, we can conclude that Chinese Sparrowhawks reach their maximum home range in the summer and have multiple nuclear domains.
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Valenta, Marko. "The Nexus of Asylum Seeker Migrations and Asylum Policy: Longitudinal Analysis of Migration Trends in Norway." International Journal on Minority and Group Rights 21, no. 3 (August 19, 2014): 371–94. http://dx.doi.org/10.1163/15718115-02103003.
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There has been much focus on the increased influx of asylum seekers in Norway and in Europe in general. This article investigates links between the influx of asylum seekers and developments in asylum policies in Norway. In focus are the immigration trends of the four largest groups of asylum seekers in Norway in the period 2006–2012. It is assumed that developments in the arrival of asylum seekers are to a large extent influenced by the ways in which the four groups were treated by migration authorities in Norway. This analysis is based on policy survey and available statistics. The longitudinal analysis indicates that changes in rejection, approval and deportation rates correspond to a large extent with subsequent fluctuations in annual arrivals of asylum seekers. It is also maintained that the restrictions in social rights result in deteriorating living conditions, but as a tool of migration control such restrictions do not work in accordance with the intention. The findings are of clear relevance for on-going discussions on asylum seeker mobility and discussions on minimum standards for reception of asylum seekers.
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Carey, Michael P., Vanessa R. von Biela, Randy J. Brown, and Christian E. Zimmerman. "Migration strategies supporting salmonids in Arctic Rivers: A case study of Arctic Cisco and Dolly Varden." Animal Migration 8, no. 1 (January 1, 2021): 132–43. http://dx.doi.org/10.1515/ami-2020-0115.
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Abstract Amphidromous fish such as Dolly Varden (Salvelinus malma) and Arctic Cisco (Coregonus autumnalis) have distinct life histories that facilitate their success in Arctic environments. Both species spawn in freshwater and make annual migrations between marine, brackish, or freshwater environments. Dolly Varden rear for one or more years in freshwater before migrating to sea whereas Arctic Cisco migrate to sea during their first summer. By contrast, Pacific salmon (Oncorhynchus spp.) spawn in freshwater, but once they smolt and go to sea they remain there until they mature and return to spawn. Salmon migrate at variable ages depending on species. Arctic marine environments offer productive food resources during summer, but during winter they are too cold for salmonids that lack antifreeze proteins. To avoid the cold sea during winter, Dolly Varden return to freshwater while Arctic Cisco overwinter in brackish estuaries. The lack of migration back to freshwater for overwintering helps explain why Pacific salmon success is limited in Arctic waters and suggests major increases in success will not be realized until Arctic seas provide suitable overwinter conditions. In this paper we contrast these migration strategies, discuss potential changes in a warming Arctic, and highlight information needs especially for juvenile fish.
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Larson, Douglas L., Jacob G. Kimmel, Joseph J. Riedy, Jonathan Hegna, Edward A. Baker, and Kim T. Scribner. "Male lake sturgeon (Acipenser fulvescens) migratory and spawning behaviors are associated with sperm quality and reproductive success." Canadian Journal of Fisheries and Aquatic Sciences 77, no. 12 (December 2020): 1943–59. http://dx.doi.org/10.1139/cjfas-2020-0124.
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Intra-annual reproductive investments may not be predictive of male reproductive success because of the effects of intra- and intersexual interactions on sperm depletion. For long-lived iteroparous fish species such as lake sturgeon (Acipenser fulvescens), reproductive effort may affect lifetime reproductive success. Radio frequency identification antennas were placed at the mouth of the Upper Black River, Michigan, and downstream of spawning locations to quantify male migratory and mating behaviors, including upstream migration time (UT), river residence time (RT), number of intra-annual spawning migrations (IM), interannual spawning interval, and operational sex ratio during 2017–2018. Computer assisted sperm analysis was used to quantify sperm quality. RT had a strong negative influence on sperm concentration and with measures of sperm quality. RT and the number of females encountered were positively associated with male reproductive success (number of offspring sired) across years. RT, IM, and UT were negatively associated with sperm quality, indicating sperm depletion is a reliable measure of sexual activity. Results demonstrate trade-offs between benefits and costs associated with current reproductive effort on future reproduction.
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Parker, Steven J., Darren W. Stevens, Laura Ghigliotti, Mario La Mesa, Davide Di Blasi, and Marino Vacchi. "Winter spawning of Antarctic toothfish Dissostichus mawsoni in the Ross Sea region." Antarctic Science 31, no. 05 (August 1, 2019): 243–53. http://dx.doi.org/10.1017/s0954102019000282.
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AbstractA survey of Antarctic toothfish (Dissostichus mawsoni) was conducted in the northern Ross Sea region during the winter of 2016 to document the timing and location of spawning activity, to collect biological information about reproductive status during the spawning season and to look for temporal signals in biological data from D. mawsoni that may indicate a spawning migration of mature toothfish from the continental slope region to the northern Ross Sea region. The 58 day survey showed that spawning of D. mawsoni began on some seamounts by early July. No changes were detected between winter and summer in length, age, sex ratio or condition factor distributions for D. mawsoni in the northern Ross Sea as hypothesized following a spawning migration from the slope to the northern Ross Sea region. These results suggest that the distribution of D. mawsoni in the Ross Sea is mainly accomplished through ontogenetic migration and not annual return spawning migrations.
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Korytár, Ľ., M. Prokeš, A. Ondrejková, and S. Zemanová. "Relationships Between the Spread of Pathogens and the Migratory Connectivity of European Wild Birds." Folia Veterinaria 64, no. 1 (March 1, 2020): 27–31. http://dx.doi.org/10.2478/fv-2020-0004.
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AbstractAmong emerging infectious diseases, 75 % are zoonotic. Migratory birds are important to public health because they carry emerging zoonotic pathogens or infected arthropod vectors. Disease is an important factor in the evolution of avian migrations and patterns of migratory connectivity. Research suggests that pathogen densities and diseases may influence the evolution of migratory behaviour. During the annual life cycle, European migratory birds spend: 2—4 months at the breeding locality, approximately 6 months on the wintering grounds, and several months (3 and more) on migration routes. There are many factors which determine when and where an outbreak of a disease may occur. Therefore, a complete understanding of the avian migratory systems has a high priority in the prevention of future outbreaks.
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Casazza, Michael L., Peter S. Coates, Cory T. Overton, and Kristy B. Howe. "Intra-annual patterns in adult band-tailed pigeon survival estimates." Wildlife Research 42, no. 5 (2015): 454. http://dx.doi.org/10.1071/wr14199.
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Context The band-tailed pigeon (Patagioenas fasciata) is a migratory species occurring in western North America with low recruitment potential and populations that have declined an average of 2.4% per year since the 1960s. Investigations into band-tailed pigeon demographic rates date back to the early 1900s, and existing annual survival rate estimates were derived in the 1970s using band return data. Aims The primary purpose of the paper was to demonstrate that the apparent paradox between band-tailed pigeon population dynamics (long-term steady decline) and breeding season survival rates (very high) can be explained by changes in survival probability during the remainder of the year. Methods We trapped Pacific coast band-tailed pigeons during two separate periods: we equipped pigeons with very high frequency (VHF) radio-transmitters in 1999–2000 (1999 = 20; 2000 = 34); and outfitted pigeons with solar powered platform transmitting terminal (PTT) transmitters in 2006–08 (n = 20). We used known fate models to estimate annual survival rates and seasonal survival variation among four periods based on an annual behavioural cycle based on phenological events (nesting, autumn migration, winter and spring migrations). We used model averaged parameter estimates to account for model selection uncertainty. Key results Neither body condition nor sex were associated with variation in band-tailed pigeon survival rates. Weekly survival during the nesting season did not differ significantly between VHF-marked (0.996; CI = 0.984–0.999) and PTT-marked pigeons (0.998; CI = 0.990–1.00). Model averaged annual survival of PTT-marked pigeons was 0.682 (95% CI = 0.426–0.861) and was similar to annual survival estimated in previous studies using band return data. Survival probability was lowest during both migration periods and highest during the nesting period. Conclusions Our survival estimates are consistent with those of prior studies and suggest that mortality risk is greatest during migration. Weekly survival probability during winter was nearly the same as during the nesting season; however, winter was the longest period and survival throughout winter was lower than other seasons. Implications We present the first inter-seasonal analysis of survival probability of the Pacific coast race of band-tailed pigeons and illustrate important temporal patterns that may influence future species management including harvest strategies and disease monitoring.
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Charles, S., R. Bravo De La Parra, J. P. Mallet, H. Persat, and P. Auger. "Annual spawning migrations in modelling brown trout population dynamics inside an arborescent river network." Ecological Modelling 133, no. 1-2 (August 2000): 15–31. http://dx.doi.org/10.1016/s0304-3800(00)00277-5.
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Lankin, G., S. P. Worner, S. Samarasinghe, and D. A. J. Teulon. "Can artificial Neural Network Systems be used for forecasting aphid flight patterns." New Zealand Plant Protection 54 (August 1, 2001): 188–92. http://dx.doi.org/10.30843/nzpp.2001.54.3720.
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In Canterbury the cereal aphid (Rhopalosiphum padi) has a bimodal annual flight pattern with peaks in autumn and late spring The autumn peak coincides with the migration of aphids into autumn and winter sown wheat The timing magnitude and duration of flights vary dramatically from year to year and can have important implications for the management of this aphid in cereals Twenty years of climatic and aphid flight data were used to train a neural network to obtain a model to predict the date and size of aphid migrations in cereal crops in Canterbury New Zealand The model provided an exceptional fit to the ten years of training data but gave disappointingly poor prediction for the eight years of validation data Possible reasons for poor prediction of validation data are given and suggestions are made concerning future developments
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Parker, Brian R., and William G. Franzin. "Reproductive biology of the quillback, Carpiodes cyprinus, in a small prairie river." Canadian Journal of Zoology 69, no. 8 (August 1, 1991): 2133–39. http://dx.doi.org/10.1139/z91-298.
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Quillback (Carpiodes cyprinus (Lesueur)) spawning migrations were monitored in 1984 and 1985 in the Ochre River, Manitoba. Quillback migrations were limited by both water temperature and discharge. Upstream spawning migrations began after water temperatures reached 5 °C but only when discharges were high. Quillback migrated up to 32 km upstream from Dauphin Lake during periods of high discharge but only 2–3 km upstream if discharges were low. Quillback probably are annual spawners and spawned from mid-April to mid-June at water temperatures between 7 and 18 °C. Fecundity ranged from 46 600 to 360 000 ova in females of 912–3410 g wet weight. Fecundity had a linear relationship to quillback wet weight. Relative gonad weight, ova diameter, and dry weight of ova all increased with increasing female weight. Fertilized ova hatched after 13–17 calendar days or 220.7–229.8 degree-days. The mean total length of newly hatched larvae was 7.95 mm. Tubercle distributions were similar to previously described patterns except that, in addition, Dauphin Lake quillback bore tubercles on the dorsal surface of the head, the anal and caudal fins, and the cornea of the eye.
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Brown, R. J., D. W. Daum, S. J. Zuray, and W. K. Carter III. "Documentation of Annual Spawning Migrations of Anadromous Coregonid Fishes in a Large River using Maturity Indices, Length and Age Analyses, and CPUE." Advances in Limnology 63 (April 2, 2012): 101–16. http://dx.doi.org/10.1127/advlim/63/2012/101.
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Watanabe, Yuuki Y., Kenneth J. Goldman, Jennifer E. Caselle, Demian D. Chapman, and Yannis P. Papastamatiou. "Comparative analyses of animal-tracking data reveal ecological significance of endothermy in fishes." Proceedings of the National Academy of Sciences 112, no. 19 (April 20, 2015): 6104–9. http://dx.doi.org/10.1073/pnas.1500316112.
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Despite long evolutionary separations, several sharks and tunas share the ability to maintain slow-twitch, aerobic red muscle (RM) warmer than ambient water. Proximate causes of RM endothermy are well understood, but ultimate causes are unclear. Two advantages often proposed are thermal niche expansion and elevated cruising speeds. The thermal niche hypothesis is generally supported, because fishes with RM endothermy often exhibit greater tolerance to broad temperature ranges. In contrast, whether fishes with RM endothermy cruise faster, and achieve any ecological benefits from doing so, remains unclear. Here, we compiled data recorded by modern animal-tracking tools for a variety of free-swimming marine vertebrates. Using phylogenetically informed allometry, we show that both cruising speeds and maximum annual migration ranges of fishes with RM endothermy are 2–3 times greater than fishes without it, and comparable to nonfish endotherms (i.e., penguins and marine mammals). The estimated cost of transport of fishes with RM endothermy is twice that of fishes without it. We suggest that the high energetic cost of RM endothermy in fishes is offset by the benefit of elevated cruising speeds, which not only increase prey encounter rates, but also enable larger-scale annual migrations and potentially greater access to seasonally available resources.
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Sinsch, Ulrich. "Movement ecology of amphibians: from individual migratory behaviour to spatially structured populations in heterogeneous landscapes,." Canadian Journal of Zoology 92, no. 6 (June 2014): 491–502. http://dx.doi.org/10.1139/cjz-2013-0028.
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Both genetic cohesion among local populations of animals and range expansion depend on the frequency of dispersers moving at an interpatch scale. Animal movement has an individual component that reflects behaviour and an ecological component that reflects the spatial organization of populations. The total movement capacity of an individual describes maximum movement distance theoretically achievable during a lifetime, whereas its variation among the members of a local population determines the magnitude of interpatch movements and thus of gene flow between neighbouring patches within metapopulation or patchy population systems. Here, I review information on dispersal and migration as components of the movement capacity of juvenile and adult pond-breeding amphibians and discuss how these components inform the spatial structure of populations. Amphibians disperse as juveniles and adults, but movement distances detected in tracking or capture–mark–recapture studies are usually far below the corresponding estimates based on molecular gene-flow data. This discrepancy reflects the constraints of available tracking methods for free-ranging individuals leading to inappropriate surrogates of annual movement capacity, but can be resolved using probabilistic approaches based on dispersal functions. There is remarkable capacity for and plasticity in movements in amphibians. Annual within-patch movements (migrations) of individuals can be large and likely represent an underestimated capacity for movement at the interpatch scale. Landscape resistance may influence the paths of dispersing amphibians, but rarely impedes interpatch movements. Juveniles emigrating unpredictably far from the natal pond and adults switching from within-patch migrations to dispersal to another patch demonstrate the plasticity of individual movement behaviour. Three basic conclusions can be drawn with respect to the linkage of individual movement behaviour and spatial or genetic structure of local amphibian populations embedded in a heterogeneous landscape: (1) individual movements or consecutive short-term series of movements are misleading surrogate measures of total movement capacity; (2) probabilistic modelling of movement capacity is the best available behavioural predictor of interpatch gene flow; (3) connectivity of local populations in heterogeneous landscapes is less affected by landscape resistance than previously expected.
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Chen, Xi. "Nighttime Lights and Population Migration: Revisiting Classic Demographic Perspectives with an Analysis of Recent European Data." Remote Sensing 12, no. 1 (January 3, 2020): 169. http://dx.doi.org/10.3390/rs12010169.
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This study examines whether the Visible Infrared Imaging Radiometer Suite (VIIRS) nighttime lights can be used to predict population migration in small areas in European Union (EU) countries. The analysis uses the most current data measured at the smallest administrative unit in 18 EU countries provided by the European Commission. The ordinary least squares regression model shows that, compared to population size and gross domestic product (GDP), lights data are another useful predictor. The predicting power of lights is similar to population but it is much stronger than GDP per capita. For most countries, regression models with lights can explain 50–90% of variances in small area migrations. The results also show that the annual VIIRS lights (2015–2016) are slightly better predictors for migration population than averaged monthly VIIRS lights (2014–2017), and their differences are more pronounced in high latitude countries. Further, analysis of quadratic models, models with interaction effects and spatial lag, shows the significant effect of lights on migration in the European region. The study concludes that VIIRS nighttime lights hold great potential for studying human migration flow, and further open the door for more widespread application of remote sensing information in studying dynamic demographic processes.
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Siletti, Alida. "Les Rapports annuels du Réseau européen des migrations : Analyse comparée." Roczniki Humanistyczne 67, no. 5 (July 24, 2019): 121. http://dx.doi.org/10.18290/rh.2019.67.5-7.
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This research analyses six Annual Reports (AR) written by the European Migration Network, in particular two general AR (written in English) and four AR depending on its French and Italian National Contact Points (written in French and in English, respectively). It aims at studying the way in which paratext — namely Peircean diagrams (maps, boxes and charts) — does not only contribute to a better textual comprehension by the target public as compared with AR in which these tools are rare or lacking, but also convey their authors’ opinion. Our hypothesis, verified during the analysis, consists of inferring that the EMN chooses official and reliable data to catch public’s attention, so not respecting neutrality which may deal with an official report of an institution. If the usage of Peircean diagrams is wider in the EMN AR than in its NCP AR, these tools represent reliability for institutions and politicians who may be interested in reading them, but they are also a source of authority for editors who write them. This research is based on the analysis of expert and institutional discourse (Maingueneau 2002; 2004; Maris 2002; Cussó & Gobin 2008) and on its pragmatic outcomes (Bouchard 2015; Espeland 2015).
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Yermokhin, M. V., and V. G. Tabachishin. "Phenological changes in the wintering end date of Pelophylax ridibundus (Pallas, 1771) (Ranidae, Anura) in the Medveditsa river valley (Saratov region) under conditions of climate transformation." Povolzhskiy Journal of Ecology, no. 4 (December 23, 2022): 474–82. http://dx.doi.org/10.35885/1684-7318-2022-4-474-482.
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The time series of dates of the end of wintering and the beginning of spawning migrations of the marsh frog in the valley of the middle reaches of the Medveditsa river (Don basin, Saratov region) was analyzed. It has been established that in the period from 1892 to 2021, the phenological norm of this phase of the annual cycle shifted to earlier dates by an average of 6 days (from May 2 to April 26) against the background of climate warming. Possible consequences of this transformation of the spring phenology of anurans in connection with the changes established are discussed. Continued monitoring of phenological changes in the spring phase of the annual cycle is required to form a forecast of the population dynamics of this anuran species and the scientific basis for their conservation.
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Lagassé, Benjamin J., Richard B. Lanctot, Stephen Brown, Alexei G. Dondua, Steve Kendall, Christopher J. Latty, Joseph R. Liebezeit, et al. "Migratory network reveals unique spatial-temporal migration dynamics of Dunlin subspecies along the East Asian-Australasian Flyway." PLOS ONE 17, no. 8 (August 4, 2022): e0270957. http://dx.doi.org/10.1371/journal.pone.0270957.
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Determining the dynamics of where and when individuals occur is necessary to understand population declines and identify critical areas for populations of conservation concern. However, there are few examples where a spatially and temporally explicit model has been used to evaluate the migratory dynamics of a bird population across its entire annual cycle. We used geolocator-derived migration tracks of 84 Dunlin (Calidris alpina) on the East Asian-Australasian Flyway (EAAF) to construct a migratory network describing annual subspecies-specific migration patterns in space and time. We found that Dunlin subspecies exhibited unique patterns of spatial and temporal flyway use. Spatially, C. a. arcticola predominated in regions along the eastern edge of the flyway (e.g., western Alaska and central Japan), whereas C. a. sakhalina predominated in regions along the western edge of the flyway (e.g., N China and inland China). No individual Dunlin that wintered in Japan also wintered in the Yellow Sea, China seas, or inland China, and vice-versa. However, similar proportions of the 4 subspecies used many of the same regions at the center of the flyway (e.g., N Sakhalin Island and the Yellow Sea). Temporally, Dunlin subspecies staggered their south migrations and exhibited little temporal overlap among subspecies within shared migration regions. In contrast, Dunlin subspecies migrated simultaneously during north migration. South migration was also characterized by individuals stopping more often and for more days than during north migration. Taken together, these spatial-temporal migration dynamics indicate Dunlin subspecies may be differentially affected by regional habitat change and population declines according to where and when they occur. We suggest that the migration dynamics presented here are useful for guiding on-the-ground survey efforts to quantify subspecies’ use of specific sites, and to estimate subspecies’ population sizes and long-term trends. Such studies would significantly advance our understanding of Dunlin space-time dynamics and the coordination of Dunlin conservation actions across the EAAF.
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Birtchnell, Thomas. "Mobilities and the Multinatural." Transfers 6, no. 2 (June 1, 2016): 120–27. http://dx.doi.org/10.3167/trans.2016.060209.
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This article examines whether the mobilities paradigm could be more sensitive to recent debates about the more-than-human (animals, plants, and insects) and indeed the inhuman (geological, planetary, and biophysical). Many possible examples spring to mind: the forced movement of people due to “natural” catastrophes, the annual migrations of birds across vast distances, the accidental and intentional spread of invasive weeds. “Multinatural mobilities” are at present both inside and outside of the paradigm’s core themes. Can mobilities go beyond transportation, migration, urban development, the hypermobility of the few, and the comparative immobility of the world’s majority of people to encompass everything that moves? Or does this risk diluting the novelty of the paradigm? By presenting a test case of a potential research theme on wild animals in India’s urban spaces, this article argues that by thinking multinaturally progress can be reached in applying the rich mobilities framework to problems in mobility systems.
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Loher, Timothy. "Analysis of match–mismatch between commercial fishing periods and spawning ecology of Pacific halibut (Hippoglossus stenolepis), based on winter surveys and behavioural data from electronic archival tags." ICES Journal of Marine Science 68, no. 10 (September 15, 2011): 2240–51. http://dx.doi.org/10.1093/icesjms/fsr152.
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Abstract Loher, T. 2011. Analysis of match–mismatch between commercial fishing periods and spawning ecology of Pacific halibut (Hippoglossus stenolepis), based on winter surveys and behavioural data from electronic archival tags. – ICES Journal of Marine Science, 68: 2240–2251. The fishery for halibut (Hippoglossus stenolepis) in the eastern Pacific is closed during the boreal winter, roughly corresponding to the seasonal spawning of the species. Opening and closing dates for each season are stipulated annually based on economics and biology. Historical surveys and data from electronic tags are analysed to assess the extent to which recent closures have encompassed the annual spawning cycle of the species, as defined by migration to offshore spawning sites, active spawning, and return to feeding areas. These were assessed by calculating mean maximum daily depth profiles for fish exhibiting seasonal migration, calculating the date-specific proportions of the tagged population either migrating to or resident on their feeding or spawning grounds, and examining the temporal distribution of spent and running fish in historical surveys along with evidence of spawning contained in high-resolution tag data. The data indicate that fishery closures over the past 20 years have been consistently too short to protect the entirety of a migration period that begins as early as September and is not substantially completed until May. Additionally, some recent season openings have encroached on the active spawning season. Failure to fully protect spawning migrations may allow seasonal interception fisheries, and the selective removal of early and late spawners could cause changes in stock demographics, restrict effective spawning, and influence long-term stock productivity, especially in the face of environmental variability.
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Gwinner, E. "Circadian and circannual programmes in avian migration." Journal of Experimental Biology 199, no. 1 (January 1, 1996): 39–48. http://dx.doi.org/10.1242/jeb.199.1.39.
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In migratory birds, endogenous daily (circadian) and annual (circannual) rhythms serve as biological clocks that provide the major basis for their temporal orientation. Circannual rhythms are responsible for the initiation of migration both in autumn and spring. This function of timing migrations is particularly important for birds that spend the winter close to the equator where the environment is too constant or irregular to provide accurate timing cues. In addition, circannual rhythms produce programmes that determine both the temporal and the spatial course of migration. In Sylvia warblers, the time programmes controlling autumn migration are organized in a species- or population-specific manner. It has been proposed that, in first-year migrants, the time programme for autumn migration plays a major role in determining migratory distance, thus providing the vector component in a mechanism of vector navigation. It is not yet clear, however, whether this programme does indeed determine migratory distance or whether it only provides the temporal framework within which other factors determine how far a bird flies. Evidence against the first alternative comes from findings indicating that migratory activity can be drastically modified by a constellation of rather specific, but highly relevant, factors and that the resulting changes in migratory activity are not compensated by subsequent increases or decreases of migratory activity. In normally day-active but nocturnally migrating birds, circannual signals cause alterations in the circadian system leading to the development of nocturnal activity. Although the nature of these signals is unknown, there is evidence that changes in the diurnal pattern of melatonin secretion by the pineal gland are associated with, and possibly causally involved in, the waxing and waning of nocturnal activity. These changes in the melatonin pattern presumably also affect general synchronization properties of the circadian system to Zeitgebers in such a way that circadian rhythms adjust faster to new conditions after long transmeridian flights.
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Petrie, S. A., and K. L. Wilcox. "Migration chronology of Eastern-Population Tundra Swans." Canadian Journal of Zoology 81, no. 5 (May 1, 2003): 861–70. http://dx.doi.org/10.1139/z03-063.
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We used satellite platform transmitting transmitters (PTTs) in 19982000 to track spring and fall migratory movements of Tundra Swans (Cygnus columbianus columbianus) captured at Long Point, Ontario. Migration corridors reported here corroborated those identified in previous studies using alphanumerically coded neck collars. However, PTTs provided additional information on duration of spring and fall migrations, duration of stay in different staging regions, time spent on breeding and wintering areas, and migration speed. Birds migrated between the Atlantic coast and northern prairies along a narrow geographic corridor through portions of the southern Great Lakes. From the northern prairies, swans followed 3 corridors to breeding areas on the west coast of Hudson Bay, central High Arctic, and Mackenzie River delta. While swans spent considerable time on Great Lakes (27% of spring migration) and northern prairie (40%) staging areas in spring, the northern boreal forest was an important fall staging area (48% of fall migration). Tundra Swans spent 20% of the annual cycle on wintering areas, 28% on spring staging areas, 29% on breeding areas, and 23% on fall staging areas. The long duration of migration and the fact that birds spend half their lives on staging areas underscore the importance of conserving Tundra Swan migratory habitats. Thirty-gram neck-collar-attached PTTs were more suitable than 95-g Teflon-harness-attached backpack PTTs for tracking Tundra Swans.
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Larsen, Karl W. "Movements and behavior of migratory garter snakes, Thamnophis sirtalis." Canadian Journal of Zoology 65, no. 9 (September 1, 1987): 2241–47. http://dx.doi.org/10.1139/z87-339.
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Although garter snake populations in northern areas have been shown to undergo annual migrations, no detailed information has been available on these movements. Through biotelemetry and, to a lesser extent, mark–recapture methods, the migration of an extreme northern population of Thamnophis sirtalis was documented. Snakes emerging from a hibernaculum moved towards the closest freshwater marsh, which was approximately 3.75 km away. Radio-tracked individuals moved along a constant bearing; once they reached the proximal regions of the marsh, they continued to move away from the den, but circled back during the later part of the summer. One individual completed a round trip of over 15 km during one active season. Snakes routinely exhibited a distinct behavioral sequence during the daily travels, and five rather lengthy searches for overnight retreats were observed. The extensive migration documented in this study may be quite costly for the northern snakes, for (i) it may significantly decrease the time available for other important activities, such as feeding, and (ii) it increases the snakes' exposure to the adverse spring and fall weather conditions, which in turn may subject them to predation or lethal temperatures.
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Miethe, Tanja, Tomas Gröhsler, Uwe Böttcher, and Christian von Dorrien. "The effects of periodic marine inflow into the Baltic Sea on the migration patterns of Western Baltic spring-spawning herring." ICES Journal of Marine Science 71, no. 3 (October 17, 2013): 519–27. http://dx.doi.org/10.1093/icesjms/fst166.
Full textAbstract:
Abstract Western Baltic spring-spawning herring (WBSSH, Clupea harengus L.) perform seasonal migrations between feeding grounds in the Skagerrak and Kattegat and their spawning sites in the Western Baltic Sea. The Sound, connecting the Kattegat to the Western Baltic Sea, is an important aggregation and transition zone for this herring stock during its spawning migration. We analysed data from the German autumn acoustic surveys of the years 1993–2009. These data revealed at least two different distribution patterns of herring in autumn: herring generally aggregated in the Sound, but in some years the majority of herring were detected further south, being outside of the Sound by the time of the survey. We tested whether observed annual differences in the herring migration can be explained by either stock characteristics (age and size) or hydrographical variables (salinity and oxygen concentration). Our results suggest that rather than being related to stock characteristics, the distribution pattern of herring was related to environmental conditions, i.e. to marine inflow events into the Baltic Sea. Barotropic inflow events in late summer and early autumn seem to prevent deoxygenation in the Sound and thereby favour the prolonged aggregation of herring in the Sound.