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Eikenaar C, Ostolani A, Hessler S, Ye EY, Karwinkel T, Isaksson C. Stopovers Serve Physiological Recovery in Migratory Songbirds. Physiol Biochem Zool 2023; 96:378-389. [PMID: 37713714 DOI: 10.1086/726788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/17/2023]
Abstract
AbstractMigrating birds perform extreme endurance exercise when flying. This shifts the balance between the production of reactive oxygen species and the antioxidant defense system toward the former, potentially generating oxidative damages. In between migratory flights, birds make stopovers, where besides accumulating fuel (mainly fats), they are assumed to rest and recover from the strenuous flight. We performed a series of studies on both temporarily caged (northern wheatears) and free-flying (northern wheatears and European robins) migrants to investigate whether migrants recover during stopover by decreasing the amount of oxidative lipid damage (malondialdehyde [MDA]) and/or increasing the total nonenzymatic antioxidant capacity (AOX). In caged wheatears, MDA decreased within a single day. These birds were able to simultaneously accumulate considerable amounts of fuel. Also, in the free-flying wheatears, there was a decrease in MDA during stopover; however, this process seemed incompatible with refueling. The reason for this difference could relate to constraints in the wild that are absent in caged birds, such as food limitation/composition and locomotor activity. In the robins, there was a near significant decrease in MDA concentration in relation to how long the birds were already at stopover, suggesting that this species also physiologically recovers during stopover. AOX did not change during stopover in either of the wheatear studies. For the robins, however, uric acid-corrected AOX declined during stopover. Our results show that during stopover, migrating birds rapidly reduce oxidative lipid damage, thereby likely recovering their physiological state. In addition to the commonly accepted function of refueling, stopovers thus probably serve physiological recovery.
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Eikenaar C, Hessler S, Hegemann A. Migrating birds rapidly increase constitutive immune function during stopover. ROYAL SOCIETY OPEN SCIENCE 2020; 7:192031. [PMID: 32257353 PMCID: PMC7062082 DOI: 10.1098/rsos.192031] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 01/06/2020] [Indexed: 06/01/2023]
Abstract
Migratory flight is physiologically highly demanding and has been shown to negatively affect multiple parameters of constitutive immune function (CIF), an animal's first line of physiological defence against infections. In between migratory flights, most birds make stopovers, periods during which they accumulate fuel for the next flight(s). Stopovers are also commonly thought of as periods of rest and recovery, but what this encompasses is largely undefined. Here, we show that during stopover, northern wheatears Oenanthe oenanthe, a long-distance migratory bird, can rapidly increase constitutive innate immune function. We caught and temporarily caged birds under ad libitum food conditions at a stopover site in autumn. Within 2 days, most birds significantly increased complement activity and their ability to kill microbes. Changes in immune function were not related to the birds' food intake or extent of fuel accumulation. Our study suggests that stopovers may not only be important to refuel but also to restore immune function. Additionally, the increase in CIF could help migrating birds to deal with novel pathogens they may encounter at stopover sites.
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Affiliation(s)
- Cas Eikenaar
- Institute of Avian Research, An der Vogelwarte 21, Wilhelmshaven 26386, Germany
| | - Sven Hessler
- Institute of Avian Research, An der Vogelwarte 21, Wilhelmshaven 26386, Germany
| | - Arne Hegemann
- Department of Biology, Lund University, Ecology Building, Lund 223 62, Sweden
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Eikenaar C, Hessler S, Fischer S, Bairlein F. An exception to the rule: Captivity does not stress wild migrating northern wheatears. Gen Comp Endocrinol 2019; 275:25-29. [PMID: 30753841 DOI: 10.1016/j.ygcen.2019.02.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 02/05/2019] [Accepted: 02/08/2019] [Indexed: 12/28/2022]
Abstract
Wild animals typically suffer from stress when brought into captivity. This stress is characterized by elevated circulating glucocorticoid levels and weight loss. We here describe for the first time a case where a wild animal, the long-distance migrating northern wheatear, does not show signs of stress when caged. We captured these birds on a stopover site during their spring migration and caged them individually with ad libitum access to food and water. The birds were divided into four groups and were blood-sampled immediately in the field, a few hours after caging, one day after caging, or three days after caging, respectively. From these blood-samples we determined circulating corticosterone level. Food intake and body mass were also monitored. We found that, with very few exceptions, corticosterone levels were low and did not differ among the groups. Accordingly, almost all birds consumed huge quantities of food and substantially increased their body mass. Together these results clearly show that caging does not result in indications of stress in wild migrating northern wheatears. Confinement-specific conditions such as restricted movement normally stress animals. We suggest migratory birds may not perceive such conditions as stressors due to their hyperphagic state, a notion that requires further testing.
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Affiliation(s)
- Cas Eikenaar
- Institute of Avian Research, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany.
| | - Sven Hessler
- Institute of Avian Research, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany
| | - Sandra Fischer
- Institute of Avian Research, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany
| | - Franz Bairlein
- Institute of Avian Research, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany
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Migratory refueling affects non-enzymatic antioxidant capacity, but does not increase lipid peroxidation. Physiol Behav 2016; 158:26-32. [DOI: 10.1016/j.physbeh.2016.02.033] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 01/18/2016] [Accepted: 02/22/2016] [Indexed: 01/11/2023]
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Crespo A, Rodrigues M, Telletxea I, Ibáñez R, Díez F, Tobar JF, Arizaga J. No Habitat Selection during Spring Migration at a Meso-Scale Range across Mosaic Landscapes: A Case Study with the Woodcock (Scolopax rusticola). PLoS One 2016; 11:e0149790. [PMID: 27002975 PMCID: PMC4803235 DOI: 10.1371/journal.pone.0149790] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 02/04/2016] [Indexed: 11/18/2022] Open
Abstract
Success of migration in birds in part depends on habitat selection. Overall, it is still poorly known whether there is habitat selection amongst landbird migrants moving across landscapes. Europe is chiefly covered by agro-forestry mosaic landscapes, so migratory species associated to either agricultural landscapes or woodland habitats should theoretically find suitable stopover sites along migration. During migration from wintering to breeding quarters, woodcocks (Scolopax rusticola) tagged with PTT satellite-tracking transmitters were used to test for the hypothesis that migrants associated to agro-forest habitats have no habitat selection during migration, at a meso-scale level. Using a GIS platform we extracted at a meso-scale range habitat cover at stopover localities. Results obtained from comparisons of soil covers between points randomly selected and true stopover localities sites revealed, as expected, the species may not select for particular habitats at a meso-scale range, because the habitat (or habitats) required by the species can be found virtually everywhere on their migration route. However, those birds stopping over in places richer in cropland or mosaic habitats including both cropland and forest and with proportionally less closed forest stayed for longer than in areas with lower surfaces of cropland and mosaic and more closed forest. This suggests that areas rich in cropland or mosaic habitat were optimal.
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Affiliation(s)
- Ariñe Crespo
- Department of Ornithology, Aranzadi Sciences Society, Zorroagagaina 11, E20014 Donostia-S. Sebastián, Spain
| | - Marcos Rodrigues
- GEOFOREST Group, IUCA, Department of Geography and Land Management, University of Zaragoza, Pedro Cerbuna 12, E50009 Zaragoza, Spain
| | - Ibon Telletxea
- Club de Cazadores de Becada, Avda. Schulz 8, 4 dcha, E33208 Gijón, Asturias, Spain
| | - Rubén Ibáñez
- Club de Cazadores de Becada, Avda. Schulz 8, 4 dcha, E33208 Gijón, Asturias, Spain
| | - Felipe Díez
- Club de Cazadores de Becada, Avda. Schulz 8, 4 dcha, E33208 Gijón, Asturias, Spain
| | - Joseba F. Tobar
- Club de Cazadores de Becada, Avda. Schulz 8, 4 dcha, E33208 Gijón, Asturias, Spain
| | - Juan Arizaga
- Department of Ornithology, Aranzadi Sciences Society, Zorroagagaina 11, E20014 Donostia-S. Sebastián, Spain
- * E-mail:
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Eikenaar C, Fritzsch A, Kämpfer S, Schmaljohann H. Migratory restlessness increases and refuelling rate decreases over the spring migration season in northern wheatears. Anim Behav 2016. [DOI: 10.1016/j.anbehav.2015.11.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Schmaljohann H, Meier C, Arlt D, Bairlein F, van Oosten H, Morbey YE, Åkesson S, Buchmann M, Chernetsov N, Desaever R, Elliott J, Hellström M, Liechti F, López A, Middleton J, Ottosson U, Pärt T, Spina F, Eikenaar C. Proximate causes of avian protandry differ between subspecies with contrasting migration challenges. Behav Ecol 2015. [DOI: 10.1093/beheco/arv160] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Schmaljohann H, Korner-Nievergelt F, Naef-Daenzer B, Nagel R, Maggini I, Bulte M, Bairlein F. Stopover optimization in a long-distance migrant: the role of fuel load and nocturnal take-off time in Alaskan northern wheatears (Oenanthe oenanthe). Front Zool 2013; 10:26. [PMID: 23663358 PMCID: PMC3665591 DOI: 10.1186/1742-9994-10-26] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Accepted: 05/02/2013] [Indexed: 11/17/2022] Open
Abstract
Introduction In long-distance migrants, a considerably higher proportion of time and energy is allocated to stopovers rather than to flights. Stopover duration and departure decisions affect consequently subsequent flight stages and overall speed of migration. In Arctic nocturnal songbird migrants the trade-off between a relatively long migration distance and short nights available for travelling may impose a significant time pressure on migrants. Therefore, we hypothesize that Alaskan northern wheatears (Oenanthe oenanthe) use a time-minimizing migration strategy to reach their African wintering area 15,000 km away. Results We estimated the factors influencing the birds’ daily departure probability from an Arctic stopover before crossing the Bering Strait by using a Cormack-Jolly-Seber model. To identify in which direction and when migration was resumed departing birds were radio-tracked. Here we show that Alaskan northern wheatears did not behave as strict time minimizers, because their departure fuel load was unrelated to fuel deposition rate. All birds departed with more fuel load than necessary for the sea crossing. Departure probability increased with stopover duration, evening fuel load and decreasing temperature. Birds took-off towards southwest and hence, followed in general the constant magnetic and geographic course but not the alternative great circle route. Nocturnal departure times were concentrated immediately after sunset. Conclusion Although birds did not behave like time-minimizers in respect of the optimal migration strategies their surplus of fuel load clearly contradicted an energy saving strategy in terms of the minimization of overall energy cost of transport. The observed low variation in nocturnal take-off time in relation to local night length compared to similar studies in the temperate zone revealed that migrants have an innate ability to respond to changes in the external cue of night length. Likely, birds maximized their potential nightly flight range by taking off early in the night which in turn maximizes their overall migration speed. Hence, nocturnal departure time may be a crucial parameter shaping the speed of migration indicating the significance of its integration in future migration models.
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Affiliation(s)
- Heiko Schmaljohann
- Institute of Avian Research "Vogelwarte Helgoland", An der Vogelwarte 21, Wilhelmshaven 26836, Germany.
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Dierschke V, Mendel B, Schmaljohann H. Differential timing of spring migration in northern wheatears Oenanthe oenanthe: hurried males or weak females? Behav Ecol Sociobiol 2004. [DOI: 10.1007/s00265-004-0872-8] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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SCHMALJOHANN HEIKO, DIERSCHKE VOLKER. Optimal bird migration and predation risk: a field experiment with northern wheatears Oenanthe oenanthe. J Anim Ecol 2004. [DOI: 10.1111/j.1365-2656.2004.00905.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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