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- Data packageData from: The price of being late: short- and long-term consequences of a delayed migration timing [naturally-timed birds](2023-07-28) Bontekoe, Iris D.; Fiedler, Wolfgang; Wikelski, Martin; Flack, AndreaChoosing the right migration timing is critical for migrants because conditions encountered en route influence movement costs, survival, and, in social migrants, the availability of social information. Depending on lifetime stages, individuals may migrate at different times due to diverging constraints, affecting the composition of migration groups. To examine the consequences of a delayed migration timing, we artificially delayed the migration of juvenile white storks (Ciconia ciconia) and thereby altered their physical and social environment. Using nearly continuous 1 Hz GPS trajectories, we examined their migration behaviour, ranging from sub-second level performance to global long-distance movement, in relation to two control groups. We found that delayed storks experienced suboptimal soaring conditions, but better wind support and thereby achieved higher flight speeds than control storks. Delayed storks had a lower mortality rate than the control storks and wintered closer to the breeding area. In fact, none of the delayed storks reached the traditional African wintering areas. Thus, our results show that juvenile storks can survive migrating at the ‘wrong’ time. However, this had long-term consequences on migration decisions. We suggest that, when timing their migration, storks balance not just energy and time, but also the availability of social information.
- Data packageData from: Study "MPIAB Argos white stork tracking (1991-2017)"(2022-12-26) Berthold, Peter; Kaatz, Christoph; Kaatz, Michael; Querner, Ulrich; van den Bossche, Willem; Chernetsov, Nikita; Fiedler, Wolfgang; Wikelski, MartinSatellite tracking of white storks (Ciconia ciconia) was begun by the Max Planck Institute of Ornithology and collaborators in 1991. After solar-powered transmitters became available in 1995, extended battery life combined with the possibility to replace transmitters over time allowed monitoring the movements of individual storks across multiple migration seasons, with one individual, Prinzesschen, tracked for over a decade. Research efforts continue using primarily GSM-based tracking technologies. This dataset includes over 200 storks tagged in Belgium, Germany, Greece, Israel, Poland, Russia, South Africa, Spain and Switzerland. As noted in the deployment information, some movements are influenced by experimental manipulations. This long-term study confirms what previous several-year tracking studies of white storks had indicated: there can be great variability from year to year in the choice of winter quarters as well as in the routes and times of migration, intermediate destinations and stop-over periods, but constancy of winter quarters and migration routes is also possible. The variability may well be caused by external factors, of which food supply is probably predominant.
- Data packageData from: The price of being late: short- and long-term consequences of a delayed migration timing [control birds](2023-07-28) Bontekoe, Iris D.; Flack, Andrea; Fiedler, WolfgangChoosing the right migration timing is critical for migrants because conditions encountered en route influence movement costs, survival, and, in social migrants, the availability of social information. Depending on lifetime stages, individuals may migrate at different times due to diverging constraints, affecting the composition of migration groups. To examine the consequences of a delayed migration timing, we artificially delayed the migration of juvenile white storks (Ciconia ciconia) and thereby altered their physical and social environment. Using nearly continuous 1 Hz GPS trajectories, we examined their migration behaviour, ranging from sub-second level performance to global long-distance movement, in relation to two control groups. We found that delayed storks experienced suboptimal soaring conditions, but better wind support and thereby achieved higher flight speeds than control storks. Delayed storks had a lower mortality rate than the control storks and wintered closer to the breeding area. In fact, none of the delayed storks reached the traditional African wintering areas. Thus, our results show that juvenile storks can survive migrating at the ‘wrong’ time. However, this had long-term consequences on migration decisions. We suggest that, when timing their migration, storks balance not just energy and time, but also the availability of social information.
- Data packageData from: Moulting sites of Latvian whooper swan Cygnus cygnus cygnets fitted with GPS-GSM transmitters(2019-12-31) Boiko, Dmitrijs; Wikelski, Martin; Fiedler, WolfgangPrevious studies on Whooper Swan Cygnus cygnus cygnets hatched in Latvia have shown that c. 99% leave the country each year to moult elsewhere in their 2nd to 6th calendar years. To reveal the exact moulting sites, in 2016 ten cygnets were fitted with 91g solar-powered neck-collar-mounted GPS-GSM loggers. Moulting sites were recorded for four individuals in their 2nd calendar year, and for two of these birds in their 3rd calendar year; four birds in total. All of these moulted at sites in Russia; one was in the Republic of Karelia and three were in the Arkhangelsk Region. The mean average straight-line distance between the hatching and moulting sites was 1,451 km (range = 1,038–2,524 km). Although the data were less comprehensive, another tracked swan probably moulted in the western part of the White Sea in the Republic of Karelia. The conservation of these moulting sites is essential for the Latvian Whooper Swans to thrive.
- Data packageData from: Study "LifeTrack White Stork SW Germany" (2013-2023)(2024-01-17) Fiedler, Wolfgang; Flack, Andrea; Schäfle, Wolfgang; Keeves, Brigitta; Quetting, Michael; Eid, Babette; Schmid, Heidi; Wikelski, MartinHuman-induced changes in climate and environment are challenging the existence of migratory species. Species with diverse and flexible migratory behaviour suffer less from population decline, as they are more capable to respond by altering migratory behaviour. At the individual-level, variations in migratory behaviour may lead to differences in fitness and subsequently influence demographic dynamics. Using lifetime GPS bio-logging data from 169 white storks (Ciconia ciconia), we answer whether their recently shortened migration has survival benefit during the juvenile stage, the riskiest life period for many migrants. We also explore how other variations in migratory decisions (i.e. time, destination), movement activity (measured by the overall body dynamic acceleration), and early life conditions influence juveniles’ survival. We observed that first autumn migration was the riskiest period for juvenile white storks. Individuals that migrated shorter distances and fledged earlier experienced lower mortality risk. In addition, higher movement activity and overwintering “closer-to-home” in Europe and North Africa (84.21% of tracked individuals adopted this new strategy) were associated with higher survival. Our study shows how avian migrants can change life history decisions linked to fitness over few decades and thus helps us to understand and predict how migrants respond to the changing world.
- Data packageData from: Study "LifeTrack White Stork Rheinland-Pfalz" (2015-2023)(2024-01-17) Fiedler, Wolfgang; Hilsendegen, Christiane; Reis, Christian; Lehmann, Jessica; Hilsendegen, Pirmin; Schmid, Heidi; Wikelski, MartinHuman-induced changes in climate and environment are challenging the existence of migratory species. Species with diverse and flexible migratory behaviour suffer less from population decline, as they are more capable to respond by altering migratory behaviour. At the individual-level, variations in migratory behaviour may lead to differences in fitness and subsequently influence demographic dynamics. Using lifetime GPS bio-logging data from 169 white storks (Ciconia ciconia), we answer whether their recently shortened migration has survival benefit during the juvenile stage, the riskiest life period for many migrants. We also explore how other variations in migratory decisions (i.e. time, destination), movement activity (measured by the overall body dynamic acceleration), and early life conditions influence juveniles’ survival. We observed that first autumn migration was the riskiest period for juvenile white storks. Individuals that migrated shorter distances and fledged earlier experienced lower mortality risk. In addition, higher movement activity and overwintering “closer-to-home” in Europe and North Africa (84.21% of tracked individuals adopted this new strategy) were associated with higher survival. Our study shows how avian migrants can change life history decisions linked to fitness over few decades and thus helps us to understand and predict how migrants respond to the changing world.
- Data packageData from: Study "LifeTrack White Stork Bavaria" (2014-2023)(2024-01-17) Fiedler, Wolfgang; Leppelsack, Elke; Leppelsack, Hans; Stahl, Thomas; Wieding, Oda; Wikelski, MartinHuman-induced changes in climate and environment are challenging the existence of migratory species. Species with diverse and flexible migratory behaviour suffer less from population decline, as they are more capable to respond by altering migratory behaviour. At the individual-level, variations in migratory behaviour may lead to differences in fitness and subsequently influence demographic dynamics. Using lifetime GPS bio-logging data from 169 white storks (Ciconia ciconia), we answer whether their recently shortened migration has survival benefit during the juvenile stage, the riskiest life period for many migrants. We also explore how other variations in migratory decisions (i.e. time, destination), movement activity (measured by the overall body dynamic acceleration), and early life conditions influence juveniles’ survival. We observed that first autumn migration was the riskiest period for juvenile white storks. Individuals that migrated shorter distances and fledged earlier experienced lower mortality risk. In addition, higher movement activity and overwintering “closer-to-home” in Europe and North Africa (84.21% of tracked individuals adopted this new strategy) were associated with higher survival. Our study shows how avian migrants can change life history decisions linked to fitness over few decades and thus helps us to understand and predict how migrants respond to the changing world.
- Data packageData from: Study "LifeTrack White Stork Oberschwaben" (2014-2023)(2024-01-16) Fiedler, Wolfgang; Flack, Andrea; Schmidt, Andreas; Reinhard, Ute; Wikelski, MartinHuman-induced changes in climate and environment are challenging the existence of migratory species. Species with diverse and flexible migratory behaviour suffer less from population decline, as they are more capable to respond by altering migratory behaviour. At the individual-level, variations in migratory behaviour may lead to differences in fitness and subsequently influence demographic dynamics. Using lifetime GPS bio-logging data from 169 white storks (Ciconia ciconia), we answer whether their recently shortened migration has survival benefit during the juvenile stage, the riskiest life period for many migrants. We also explore how other variations in migratory decisions (i.e. time, destination), movement activity (measured by the overall body dynamic acceleration), and early life conditions influence juveniles’ survival. We observed that first autumn migration was the riskiest period for juvenile white storks. Individuals that migrated shorter distances and fledged earlier experienced lower mortality risk. In addition, higher movement activity and overwintering “closer-to-home” in Europe and North Africa (84.21% of tracked individuals adopted this new strategy) were associated with higher survival. Our study shows how avian migrants can change life history decisions linked to fitness over few decades and thus helps us to understand and predict how migrants respond to the changing world.
- Data packageData from: Study "LifeTrack White Stork Vorarlberg" (2016-2023)(2024-01-17) Fiedler, Wolfgang; Niederer, Walter; Schönenberger, Alwin; Flack, Andrea; Wikelski, MartinHuman-induced changes in climate and environment are challenging the existence of migratory species. Species with diverse and flexible migratory behaviour suffer less from population decline, as they are more capable to respond by altering migratory behaviour. At the individual-level, variations in migratory behaviour may lead to differences in fitness and subsequently influence demographic dynamics. Using lifetime GPS bio-logging data from 169 white storks (Ciconia ciconia), we answer whether their recently shortened migration has survival benefit during the juvenile stage, the riskiest life period for many migrants. We also explore how other variations in migratory decisions (i.e. time, destination), movement activity (measured by the overall body dynamic acceleration), and early life conditions influence juveniles’ survival. We observed that first autumn migration was the riskiest period for juvenile white storks. Individuals that migrated shorter distances and fledged earlier experienced lower mortality risk. In addition, higher movement activity and overwintering “closer-to-home” in Europe and North Africa (84.21% of tracked individuals adopted this new strategy) were associated with higher survival. Our study shows how avian migrants can change life history decisions linked to fitness over few decades and thus helps us to understand and predict how migrants respond to the changing world.
- Data packageData from: Costs of migratory decisions: a comparison across eight white stork populations(2015-06-13) Flack, Andrea; Fiedler, Wolfgang; Blas, Julio; Pokrovsky, Ivan; Mitropolsky, B.; Kaatz, Michael; Aghababyan, Karen; Khachatryan, A.; Fakriadis, Ioannis; Makrigianni, Eleni; Jerzak, Leszek; Shamin, M.; Shamina, C.; Azafzaf, H.; Mokotjomela, Thabiso M.; Feltrup-Azafzaf, Claudia; Wikelski, MartinAnnual migratory movements can range from a few tens to thousands of kilometers, creating unique energetic requirements for each specific species and journey. Even within the same species, migration costs can vary largely because of flexible, opportunistic life history strategies. We uncover the large extent of variation in the lifetime migratory decisions of young white storks originating from eight populations. Not only did juvenile storks differ in their geographically distinct wintering locations, their diverse migration patterns also affected the amount of energy individuals invested for locomotion during the first months of their life. Overwintering in areas with higher human population reduced the stork’s overall energy expenditure because of shorter daily foraging trips, closer wintering grounds, or a complete suppression of migration. Because migrants can change ecological processes in several distinct communities simultaneously, understanding their life history decisions helps not only to protect migratory species but also to conserve stable ecosystems.