Sensor:Solar Geolocator Raw
Solar Geolocator Raw
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Solar Geolocator Raw
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- Data packageData from: Study "Switzerland Biel - Long term study on migratory movement of Alpine swifts (Apus melba)"(2020-11-26) Meier, Christoph M.; Liechti, FelixFor migratory birds optimal timing of the onset of reproduction is vital, especially when suitable conditions for reproduction occur only for a short while during the year. With increasing latitude the suitable period becomes shorter and we expect the organization of annual cycle to be more synchronized to the local conditions across individuals of same population. This should result in low variation of arrival and departure date in breeding sites at higher latitudes. We quantify the temporal and geographical variation in pre‐ and post‐breeding migration between individuals from four different populations of alpine swifts Tachymarptis melba along a latitudinal gradient. We tracked 215 individuals in three years with geolocators. The two western and two eastern populations showed separate migratory flyways and places of residence in Africa. Length of stay at the breeding sites was negatively correlated with latitude and differed by more than a month between populations. Duration of migration was similarly short in all populations (median 6.2 days in autumn and 8.7 days in spring). However, variation in timing of migration was unrelated to latitude and individuals everywhere arrived in the same asynchrony at the breeding site.
- Data packageData from: Migratory routes of red-necked phalaropes Phalaropus lobatus breeding in southern Chukotka revealed by geolocators(2018-06-13) Mu, Tong; Tomkovich, Pavel S.; Loktionov, Egor Y.; Syroechkovskiy, Evgeny E.; Wilcove, David S.The migration routes of Red‐necked Phalaropes breeding around the Bering Sea are poorly known, despite the fact that the Bering Sea could mark the boundary between the East Palearctic populations that winter in the Pacific Ocean around the East Indies and the West Nearctic populations that winter in the Pacific Ocean off the coast of South America. Geolocator data retrieved from two male phalaropes tagged in southern Chukotka, Far Eastern Russia, confirm that birds breeding in this region belong to the East Palearctic population and winter in the East Indies, suggesting that the division line with the West Nearctic population is farther to the East. The routes taken by the two phalaropes were almost entirely pelagic, totaling around 18,000–20,000 km round‐trip, with the birds continuously on the move during migration, rather than resident in any particular stopover site, contrary to most other migratory shorebirds.
- Data packageData from: Breeding latitude predicts timing but not rate of spring migration in a widespread migratory bird in South America(2019-04-01) Jahn, Alex E.; Cereghetti, Joaquín; Cueto, Victor R.; Hallworth, Michael T.; Levey, Douglas J.; Marini, Miguel Â.; Masson, Diego; Pizo, Marco A.; Sarasola, José Hernán; Tuero, Diego T.(1) Identifying the processes that determine avian migratory strategies in different environmental contexts is imperative to understanding the constraints to survival and reproduction faced by migratory birds across the planet. (2) We compared the spring migration strategies of Fork-tailed Flycatchers (Tyrannus s. savana) that breed at south-temperate latitudes (i.e., austral migrants) vs. tropical latitudes (i.e., intra-tropical migrants) in South America. We hypothesized that austral migrant flycatchers are more time-selected than intra- tropical migrants during spring migration. As such, we predicted that that austral migrants, which migrate further than intra-tropical migrants, will migrate at a faster rate and that the rate of migration for austral migrants will be positively correlated with the onset of spring migration. (3) We attached light-level geolocators to Fork-tailed Flycatchers at two tropical breeding sites in Brazil and at two south-temperate breeding sites in Argentina and tracked their movements until the following breeding season. (4) Of 286 geolocators that were deployed, 37 were recovered ~1 year later, of which 28 provided useable data. Rate of spring migration did not differ significantly between the two groups, and only at one site was there a significantly positive relationship between date of initiation of spring migration and arrival date. (5) This represents the first comparison of individual migratory strategies among conspecific passerines breeding at tropical vs. temperate latitudes and suggests that austral migrant Fork-tailed Flycatchers in South America are not more time- selected on spring migration than intra-tropical migrant conspecifics. Low sample sizes could have diminished our power to detect differences (e.g., between sexes), such that further research into the mechanisms underpinning migratory strategies in this poorly understood system is necessary.
- Data packageData from: Seasonal variation in migration strategies used to cross ecological barriers in a Nearctic migrant wintering in Africa(2019-05-20) Léandri-Breton, Don-Jean; Lamarre, Jean-François; Bety, JoëlEcological barriers such as oceans, mountain ranges or glaciers can have a substantial influence on the evolution of animal migration. Along the migration flyway connecting breeding sites in the North American Arctic and wintering grounds in Europe or Africa, Nearctic species are confronted with significant barriers such as the Atlantic Ocean and the Greenland icecap. Using geolocation devices, we identified wintering areas used by Ringed Plovers nesting in the Canadian High‐Arctic and investigated migration strategies used by these Nearctic migrants along the transatlantic route. The main wintering area of the Ringed Plovers (n = 20) was located in Western Africa. We found contrasting seasonal migration patterns, with Ringed Plovers minimizing continuous flight distances over the ocean in spring by making a detour to stop in Iceland. In autumn, however, most individuals crossed the ocean in one direct flight from Southern Greenland to Western Europe, as far as Southern Spain. This likely resulted from prevailing anti‐clockwise winds associated with the Icelandic low‐pressure system. Moreover, the plovers we tracked largely circumvented the Greenland icecap in autumn, but in spring, some plovers apparently crossed the icecap above the 65°N. Our study highlighted the importance of Iceland as a stepping‐stone during the spring migration and showed that small Nearctic migrants can perform non‐stop transatlantic flights from Greenland to Southern Europe.
- Data packageData from: Non‐breeding areas and timing of migration in relation to weather of Scottish‐breeding common sandpipers Actitis hypoleucos(2019-02-01) Summers, Ron W.; de Raad, A. Louise; Bates, Brian; Etheridge, Brian; Elkins, NormanThe number of breeding common sandpipers has declined in Britain due to poorer return rates from non‐breeding areas. To investigate little known aspects of their annual cycle, breeding common sandpipers were fitted with geolocators to track their migrations and determine their non‐breeding areas. Ten tagged birds left Scotland on 9 July (median dates and durations are given throughout the abstract). Short‐term staging was carried out by some birds in England and Ireland, then for longer by most birds in Iberia before continuing to West Africa, arriving on 28 July. Six birds spent most of the non‐breeding season (October–February) on the coast of Guinea‐Bissau, suggesting that this is a key area. Single birds occurred in Sierra Leone, Guinea, the Canary Islands and Western Sahara. The southward migration from Scotland took 17.5 days (range 1.5‐24 days), excluding the initial fuelling period. The first northward movement from Africa was on 12 April. Staging occurred in either Morocco, Iberia or France. Arrival in Scotland was on 2 May. The northward migration took 16 days (range 13.5‐20.5 days). The main migration strategy involved short‐ and medium‐range flights, using tail‐winds in most cases. Variation in strategy was associated with departure date; birds that left later staged for shorter durations. Coastal West Africa provides two major habitats for common sandpipers: mudflats associated with mangroves and rice fields. Although the area of mangrove has been depleted, the scale of loss has probably been insufficient to account for the decline in sandpiper numbers. Rice fields are expanding, providing feeding areas for water‐birds. Meteorological data during the migrations suggest that the weather during the southward migration is unlikely to contribute to a population decline but strong cross‐winds or head‐winds during the northward migration to the breeding grounds may do so.
- Data packageData from: Concentration of a widespread breeding population in few critically important nonbreeding areas: migratory connectivity in the Prothonotary Warbler(2019-07-03) Tonra, Christopher M.; Hallworth, Michael T.; Boves, Than J.; Reese, Jessie; Bulluck, Lesley P.; Johnson, Matthew; Viverette, Cathy; Percy, Katie; Ames, Elizabeth M.; Matthews, Alix; Slevin, Morgan C.; Wilson, R. Randy; Johnson, Erik I.One of the greatest challenges to informed conservation of migratory animals is elucidating spatiotemporal variation in distributions. Without such information, it is impossible to understand full-annual-cycle ecology and effectively implement conservation actions that address where and when populations are most limited. We deployed and recovered light-level geolocators (n = 34) at 6 breeding sites in North America across the breeding range of a declining long-distance migratory bird, the Prothonotary Warbler (Protonotaria citrea). We sought to determine migratory routes, stopover location and duration, and the location of overwintering grounds. We found that the species exhibits a large-scale, east‒west split in migratory routes and weak migratory connectivity across its range. Specifically, almost all individuals, regardless of breeding origin, overlapped in their estimated wintering location in northern Colombia, in an area 20% the size of the breeding range. Additionally, most of the individuals across all breeding locations concentrated in well-defined stopover locations in Central America while en route to Colombia. Although error inherent in light-level geolocation cannot be fully ruled out, surprisingly much of the estimated wintering area included inland areas even though the Prothonotary Warbler is considered a specialist on coastal mangroves in winter. Based on these results, conservation efforts directed at very specific nonbreeding geographical areas will potentially have benefits across most of the breeding population. Our findings highlight the importance of using modern technologies to validate assumptions about little-studied portions of a species’ annual cycle, and the need to distribute sampling across its range.
- Data packageData from: Constructing and evaluating a continent-wide migratory songbird network across the annual cycle(2018-02-26) Knight, Samantha M.; Bradley, David W.; Clark, Robert G.; Gow, Elizabeth A.; Bélisle, Marc; Berzins, Lisha L.; Blake, Tricia; Bridge, Eli S.; Burke, Lauren; Dawson, Russell D.; Dunn, Peter O.; Garant, Dany; Holroyd, Geoffrey L.; Hussell, David J.T.; Lansdorp, Olga; Laughlin, Andrew J.; Leonard, Marty L.; Pelletier, Fanie; Shutler, Dave; Siefferman, Lynn; Taylor, Caz M.; Trefry, Helen E.; Vleck, Carol M.; Vleck, David; Winkler, David Ward; Whittingham, Linda A.; Norris, D. RyanDetermining how migratory animals are spatially connected between breeding and non-breeding periods is essential for predicting the effects of environmental change and for developing optimal conservation strategies. Yet, despite recent advances in tracking technology, we lack comprehensive information on the spatial structure of migratory networks across a species’ range, particularly for small-bodied, long-distance migratory animals. We constructed a migratory network for a songbird and used network-based metrics to characterize the spatial structure and prioritize regions for conservation. The network was constructed using year-round movements derived from 133 archival light-level geolocators attached to Tree Swallows (Tachycineta bicolor) originating from 12 breeding sites across their North American breeding range. From these breeding sites, we identified 10 autumn stopover nodes (regions) in North America, 13 non-breeding nodes located around the Gulf of Mexico, Mexico, Florida, and the Caribbean, and 136 unique edges (migratory routes) connecting nodes. We found strong migratory connectivity between breeding and autumn stopover sites and moderate migratory connectivity between the breeding and non-breeding sites. We identified three distinct ‘communities’ of nodes that corresponded to western, central, and eastern North American flyways. Several regions were important for maintaining network connectivity, with South Florida and Louisiana as the top ranked non-breeding nodes and the Midwest as the top ranked stopover node. We show that migratory songbird networks can have both a high degree of mixing between seasons yet still show regionally distinct migratory flyways. Such information will be crucial for accurately predicting factors that limit and regulate migratory songbirds throughout the annual cycle. Our study highlights how network-based metrics can be valuable for identifying overall network structure and prioritizing specific regions within a network for conserving a wide variety of migratory animals.
- Data packageData from: Autumn migration and wintering site of a wood warbler Phylloscopus sibilatrix breeding in Denmark identified using geolocation(2018-11-28) Tøttrup, Anders P.; Pedersen, Lykke; Thorup, KasperBackground: Basic knowledge of detailed spatiotemporal migration patterns is lacking for most migratory bird species. Using the smallest available geolocator, we aim to map autumn migration and wintering areas of north European wood warblers Phylloscopus sibilatrix and compare the spatiotemporal pattern with recoveries of individuals ringed across Europe. Results: A tracked wood warbler migrated south-south-east to sub-Saharan Africa in Sudan and then west-south-west to winter in Côte d’Ivoire. The timing and route fits well within the distribution of ring recoveries although the westward movement after the Sahara crossing is not revealed by the ring recoveries, but only few recoveries south of Sahara exist. Conclusions: The surprising westward movement south of the Sahara supplements the overall pattern revealed by ring recoveries and aids our understanding of the connectivity and site dependence in this generally declining species.
- Data packageData from: Prolonged stopover duration characterises migration strategy and constraints of a long-distant migrant songbird(2015-05-18) Arlt, Debora; Olsson, Peter; Fox, James W.; Low, Matthew; Pärt, TomasStopover behaviour is a central element of migration strategies. But in recent geolocator studies, despite now being able to track individual songbirds during their entire migration, their stopover behaviour has received little attention. We used light-sensitive geolocators to identify the migratory routes and schedules of 12 northern wheatears (Oenanthe oenanthe) breeding in Sweden. Three geolocators collected temperature data complementing inferences from light data by providing additional information on behaviour during migration. The wheatears performed a slow migration with considerable stopover time (84%/76% of autumn/spring migration), with short stops while traveling through Europe, and a prolonged stopover period in both autumn and spring in the Mediterranean region. Spring migration was faster than autumn migration, mainly because of decreased stopover time. Migration routes and time schedules were similar to those from a German breeding population. Compared to wheatears breeding in Alaska with a three-fold migration distance, Swedish wheatears spent more time during stopovers during autumn and spring migration, suggesting less time constraints and potential flexibility in migration schedules. The finding of prolonged stopovers, similar to other recent geolocator studies, shows that temporary residency periods may be common. This changes our current view on stopover ecology to one where temporary residency periods are part of spatio-temporal strategies optimising resource use during the entire annual cycle.
- Data packageData from: Kiawah and Seabrook islands are a critical site for the rufa Red Knot (Calidris canutus rufa)(2022-12-13) Pelton, Mary Margaret; Padula, Sara R.; Garcia-Walther, Julian; Andrews, Mark; Mercer, Robert; Porter, Ron; Sanders, Felicia; Thibault, Janet; Senner, Nathan; Linscott, Jennifer A.The rufa Red Knot Calidris canutus rufa is a migratory shorebird that performs one of the longest known migrations among birds and has experienced a population decline of over 85% in recent decades. During migration, rufa Red Knots rest and refuel at stopover sites along the Atlantic Coast of the USA, including Kiawah and Seabrook islands in South Carolina. We document the importance of Kiawah and Seabrook islands forknots during their spring migration using on-the-ground surveys between 19 February and 20 May 2021 to record the occurrence and proportion of individually marked knots, as well as geolocators deployed on knots captured in the area. Using a superpopulation model, we estimated a minimum passage population of 17,247 knots (95% CI: 13,548–22,099; ~41% of the total rufa knot population) and an average stopover duration of 47 days (95% CI: 40.1–54.8). Our geolocator results showed that knots using Kiawah and Seabrook islands can bypass Delaware Bay and fly directly to the Canadian Arctic. Finally, our geolocators, combined with resighting data from across the Atlantic Flyway, indicate that a large network of more than 70 coastal sites concentrated largely in the southeastern USA provide stopover and overwintering habitat for the knots we observed on Kiawah and Seabrook islands. These findings show that Kiawah and Seabrook islands should be recognized as critical sites in the knot network and, therefore, a conservation priority. The threats facing these sites, such as prey depletion, anthropogenic disturbance, and sea level rise, require immediate attention.