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Romanova N, Utvenko G, Prokshina A, Cellarius F, Fedorishcheva A, Pakhomov A. Migratory birds are able to choose the appropriate migratory direction under dim yellow narrowband light. Proc Biol Sci 2023; 290:20232499. [PMID: 38113940 PMCID: PMC10730290 DOI: 10.1098/rspb.2023.2499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 11/21/2023] [Indexed: 12/21/2023] Open
Abstract
Currently, it is generally assumed that migratory birds are oriented in the appropriate migratory direction under UV, blue and green light (short-wavelength) and are unable to use their magnetic compass in total darkness and under yellow and red light (long-wavelength). However, it has also been suggested that the magnetic compass has two sensitivity peaks: in the short and long wavelengths, but with different intensities. In this project, we aimed to study the orientation of long-distance migrants, pied flycatchers (Ficedula hypoleuca), under different narrowband light conditions during autumn and spring migrations. The birds were tested in the natural magnetic field (NMF) and a changed magnetic field (CMF) rotated counterclockwise by 120° under dim green (autumn) and yellow (spring and autumn) light, which are on the 'threshold' between the short-wavelength and long-wavelength light. We showed that pied flycatchers (i) were completely disoriented under green light both in the NMF and CMF but (ii) showed the migratory direction in the NMF and the appropriate response to CMF under yellow light. Our data contradict the results of previous experiments under narrowband green and yellow light and raise doubts about the existence of only short-wavelength magnetoreception. The parameters of natural light change dramatically in spectral composition and intensity after local sunset, and the avian magnetic compass should be adapted to function properly under such constantly changing light conditions.
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Affiliation(s)
- Nadezhda Romanova
- Moscow State Pedagogical University, 1/1 M. Pirogovskaya St., Moscow 119991, Russia
| | - Gleb Utvenko
- Department of Vertebrate Zoology, St. Petersburg State University, 199034 St. Petersburg, Russia
- Biological Station Rybachy, Zoological Institute RAS, Kaliningrad Region, Rybachy 238535, Russia
| | - Anisia Prokshina
- Department of Vertebrate Zoology, Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Fyodor Cellarius
- Department of Vertebrate Zoology, Lomonosov Moscow State University, 119234 Moscow, Russia
| | | | - Alexander Pakhomov
- Biological Station Rybachy, Zoological Institute RAS, Kaliningrad Region, Rybachy 238535, Russia
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Schmaljohann H, Eikenaar C, Sapir N. Understanding the ecological and evolutionary function of stopover in migrating birds. Biol Rev Camb Philos Soc 2022; 97:1231-1252. [PMID: 35137518 DOI: 10.1111/brv.12839] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 01/31/2022] [Accepted: 02/01/2022] [Indexed: 12/14/2022]
Abstract
Global movement patterns of migratory birds illustrate their fascinating physical and physiological abilities to cross continents and oceans. During their voyages, most birds land multiple times to make so-called 'stopovers'. Our current knowledge on the functions of stopover is mainly based on the proximate study of departure decisions. However, such studies are insufficient to gauge fully the ecological and evolutionary functions of stopover. If we study how a focal trait, e.g. changes in energy stores, affects the decision to depart from a stopover without considering the trait(s) that actually caused the bird to land, e.g. unfavourable environmental conditions for flight, we misinterpret the function of the stopover. It is thus important to realise and acknowledge that stopovers have many different functions, and that not every migrant has the same (set of) reasons to stop-over. Additionally, we may obtain contradictory results because the significance of different traits to a migrant is context dependent. For instance, late spring migrants may be more prone to risk-taking and depart from a stopover with lower energy stores than early spring migrants. Thus, we neglect that departure decisions are subject to selection to minimise immediate (mortality risk) and/or delayed (low future reproductive output) fitness costs. To alleviate these issues, we first define stopover as an interruption of migratory endurance flight to minimise immediate and/or delayed fitness costs. Second, we review all probable functions of stopover, which include accumulating energy, various forms of physiological recovery and avoiding adverse environmental conditions for flight, and list potential other functions that are less well studied, such as minimising predation, recovery from physical exhaustion and spatiotemporal adjustments to migration. Third, derived from these aspects, we argue for a paradigm shift in stopover ecology research. This includes focusing on why an individual interrupts its migratory flight, which is more likely to identify the individual-specific function(s) of the stopover correctly than departure-decision studies. Moreover, we highlight that the selective forces acting on stopover decisions are context dependent and are expected to differ between, e.g. K-/r-selected species, the sexes and migration strategies. For example, all else being equal, r-selected species (low survival rate, high reproductive rate) should have a stronger urge to continue the migratory endurance flight or resume migration from a stopover because the potential increase in immediate fitness costs suffered from a flight is offset by the expected higher reproductive success in the subsequent breeding season. Finally, we propose to focus less on proximate mechanisms controlling landing and departure decisions, and more on ultimate mechanisms to identify the selective forces shaping stopover decisions. Our ideas are not limited to birds but can be applied to any migratory species. Our revised definition of stopover and the proposed paradigm shift has the potential to stimulate a fruitful discussion towards a better evolutionary ecological understanding of the functions of stopover. Furthermore, identifying the functions of stopover will support targeted measures to conserve and restore the functionality of stopover sites threatened by anthropogenic environmental changes. This is especially important for long-distance migrants, which currently are in alarming decline.
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Affiliation(s)
- Heiko Schmaljohann
- Institute for Biology and Environmental Sciences (IBU), Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky-Straße 9-11, Oldenburg, 26129, Germany.,Institute of Avian Research, An der Vogelwarte 21, Wilhelmshaven, 26386, Germany
| | - Cas Eikenaar
- Institute of Avian Research, An der Vogelwarte 21, Wilhelmshaven, 26386, Germany
| | - Nir Sapir
- Department of Evolutionary and Environmental Biology and the Institute of Evolution, University of Haifa, 199 Aba Khoushy Ave, Haifa, 3498838, Israel
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Bauer CM, Watts HE. Corticosterone's roles in avian migration: Assessment of three hypotheses. Horm Behav 2021; 135:105033. [PMID: 34273707 DOI: 10.1016/j.yhbeh.2021.105033] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 06/30/2021] [Accepted: 07/03/2021] [Indexed: 12/30/2022]
Abstract
While corticosterone (CORT) is often suggested to be an important hormone regulating processes necessary for avian migration, there has been no systematic assessment of CORT's role in migration. Prior to migration, birds increase fat stores and flight muscle size to prepare for the high energetic costs associated with long-distance flight. After attaining sufficient energetic stores, birds then make the actual decision to depart from their origin site. Once en route birds alternate between periods of flight and stopovers, during which they rest and refuel for their next bouts of endurance flight. Here, we evaluate three non-mutually exclusive hypotheses that have been proposed in the literature for CORT's role in migration. (1) CORT facilitates physiological preparations for migration [e.g. hyperphagia, fattening, and flight muscle hypertrophy]. (2) CORT stimulates departure from origin or stopover sites. (3) CORT supports sustained migratory travel. After examining the literature to test predictions stemming from each of these three hypotheses, we found weak support for a role of CORT in physiological preparation for migration. However, we found moderate support for a role of CORT in stimulating departures, as CORT increases immediately prior to departure and is higher when migratory restlessness is displayed. We also found moderate support for the hypothesis that CORT helps maintain sustained travel, as CORT is generally higher during periods of flight, though few studies have tested this hypothesis. We provide recommendations for future studies that would help to further resolve the role of CORT in migration.
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Affiliation(s)
- Carolyn M Bauer
- Department of Biology, Swarthmore College, Swarthmore, PA, USA.
| | - Heather E Watts
- School of Biological Sciences, Washington State University, Pullman, WA, USA; Center for Reproductive Biology, Washington State University, Pullman, WA, USA
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Åkesson S, Ilieva M, Bianco G. Flexibility and Control of Circadian Activity, Migratory Restlessness and Fueling in Two Songbird Migrants. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.666176] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Juvenile songbirds rely on an endogenous program, encoding direction, distance, fueling, and timing of migration. Migratory distance is species-specific, expressed as a period of migratory restlessness, for which the length is correlated with distance, while fueling is modified to meet anticipated flight distances controlled by geomagnetic cues and amount of day-light available for foraging. How daylength affect onset and level of migratory activity and fueling decisions in wild birds have so far received limited attention. Here we study how photoperiod controls onset, level and extent of autumn migratory activity and fueling in juvenile diurnally migrating dunnocks, and nocturnally migrating European robins by experimentally increasing daylength. For both species, we kept a control group indoors at the location of capture in southern Sweden exposed to the natural photoperiod, and an experimental group with increased and advanced photoperiod by 2 h in the morning. Dunnocks initiated migratory activity at sunrise (or artificial sunrise) in both groups, demonstrating a highly responsive and flexible component for the onset of migration triggered by light. Experimental robins anticipated the end of nocturnal migratory activity predicting the earlier sunrise immediately after the time-shift and expressed this behavior already under darkness, supporting a fast-resetting mechanism to the new diel period. Timing of end of morning activity was not affected by the earlier sunrise in both species, suggesting a fixed endogenous control that persisted throughout the 13-day study period. Experimental dunnocks expressed higher overall activity and lower fuel loads than controls, while robins did not change their overall activity and fuel load in response to the shifted and increased photoperiod. These results reveal important adaptations for circadian timekeeping including both a flexible onset open to fast modifications and a more rigid end, with differential effects by the treatment on migratory activity and fueling in the two species.
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Zenzal TJ, Ward MP, Diehl RH, Buler JJ, Smolinsky J, Deppe JL, Bolus RT, Celis‐Murillo A, Moore FR. Retreat, detour or advance? Understanding the movements of birds confronting the Gulf of Mexico. OIKOS 2021. [DOI: 10.1111/oik.07834] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Theodore J. Zenzal
- U.S. Geological Survey, Wetland and Aquatic Research Center Lafayette LA USA
- School of Biological, Environmental, and Earth Sciences, Univ. of Southern Mississippi Hattiesburg MS USA
| | - Michael P. Ward
- Dept of Natural Resources and Environmental Sciences, Univ. of Illinois Urbana IL USA
| | - Robert H. Diehl
- U.S. Geological Survey, Northern Rocky Mountain Science Center Bozeman MT USA
| | - Jeffrey J. Buler
- Dept of Entomology and Wildlife Ecology, Univ. of Delaware Newark DE USA
| | - Jaclyn Smolinsky
- Dept of Entomology and Wildlife Ecology, Univ. of Delaware Newark DE USA
- Cherokee Nation System Solutions, contracted to the US Geol. Surv., Wetland and Aguatic Res. Center Lafayette LA USA
| | | | | | | | - Frank R. Moore
- School of Biological, Environmental, and Earth Sciences, Univ. of Southern Mississippi Hattiesburg MS USA
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Ward MP, Benson TJ, Deppe J, Zenzal TJ, Diehl RH, Celis-Murillo A, Bolus R, Moore FR. Estimating apparent survival of songbirds crossing the Gulf of Mexico during autumn migration. Proc Biol Sci 2018; 285:rspb.2018.1747. [PMID: 30355710 DOI: 10.1098/rspb.2018.1747] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 09/27/2018] [Indexed: 11/12/2022] Open
Abstract
Many migratory bird species are declining, and the migratory period may limit populations because of the risk in traversing large geographical features during passage. Using automated radio-telemetry, we tracked 139 Swainson's thrushes (Catharus ustulatus) departing coastal Alabama, USA and crossing the Gulf of Mexico to arrive in the Yucatan Peninsula, Mexico during autumn. We estimated apparent survival and examined how extrinsic (weather variables and day of year) and intrinsic (fat load, sex and age) factors influenced survival using a mark-recapture approach. We also examined how favourability of winds for crossing the Gulf varied over the past 25 years. Fat load, day of year and wind profit were important factors in predicting which individuals survived crossing the Gulf. Survival estimates varied with wind profit and fat, but generally, fat birds departing on days with favourable wind profits had an apparent survival probability of greater than 0.90, while lean individuals with no or negative wind profits had less than 0.33. The proportion of favourable nights varied within and among years, but has increased over the last 25 years. While conservation strategies cannot improve extrinsic factors, they can provide opportunities for birds to refuel before crossing large geographical features through protecting and creating high-quality stopover sites.
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Affiliation(s)
- Michael P Ward
- Department of Natural Resources and Environmental Sciences, University of Illinois, Urbana-Champaign, IL, USA .,Illinois Natural History Survey, Prairie Research Institute, University of Illinois, Urbana-Champaign, IL, USA
| | - Thomas J Benson
- Illinois Natural History Survey, Prairie Research Institute, University of Illinois, Urbana-Champaign, IL, USA
| | - Jill Deppe
- Department of Biological Sciences, Eastern Illinois University, Charleston, IL, USA.,National Audubon Society, Washington, DC, USA
| | - Theodore J Zenzal
- Department of Natural Resources and Environmental Sciences, University of Illinois, Urbana-Champaign, IL, USA.,School of Biological, Environmental, and Earth Sciences, University of Southern Mississippi, Hattiesburg, MI, USA
| | - Robert H Diehl
- U.S. Geological Survey, Northern Rocky Mountain Science Center, Bozeman, MT, USA
| | - Antonio Celis-Murillo
- Illinois Natural History Survey, Prairie Research Institute, University of Illinois, Urbana-Champaign, IL, USA.,U.S. Geological Survey, Patuxent Wildlife Research Center, Laurel, MD, USA
| | - Rachel Bolus
- Department of Biology, Southern Utah University, Cedar City, UT, USA
| | - Frank R Moore
- School of Biological, Environmental, and Earth Sciences, University of Southern Mississippi, Hattiesburg, MI, USA
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