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Muheim R, Phillips JB. Effects of low-level RF fields reveal complex pattern of magnetic input to the avian magnetic compass. Sci Rep 2023; 13:19970. [PMID: 37968316 PMCID: PMC10651899 DOI: 10.1038/s41598-023-46547-5] [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: 08/28/2023] [Accepted: 11/02/2023] [Indexed: 11/17/2023] Open
Abstract
The avian magnetic compass can be disrupted by weak narrow-band and broadband radio-frequency (RF) fields in the lower MHz range. However, it is unclear whether disruption of the magnetic compass results from the elimination of the perception pattern produced by the magnetic field or from qualitative changes that make the pattern unrecognizable. We show that zebra finches trained in a 4-arm maze to orient relative to the magnetic field are disoriented when tested in the presence of low-level (~ 10 nT) Larmor-frequency RF fields. However, they are able to orient when tested in such RF fields if trained under this condition, indicating that the RF field alters, but does not eliminate, the magnetic input. Larmor-frequency RF fields of higher intensities, with or without harmonics, dramatically alter the magnetic compass response. In contrast, exposure to broadband RF fields in training, in testing, or in both training and testing eliminates magnetic compass information. These findings demonstrate that low-level RF fields at intensities found in many laboratory and field experiments may have very different effects on the perception of the magnetic field in birds, depending on the type and intensity of the RF field, and the birds' familiarity with the RF-generated pattern.
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Affiliation(s)
- Rachel Muheim
- Department of Biology, Lund University, Biology Building, 223 62, Lund, Sweden.
| | - John B Phillips
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061-0406, USA
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2
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The amphibian magnetic sense(s). J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2022; 208:723-742. [PMID: 36269404 DOI: 10.1007/s00359-022-01584-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 10/02/2022] [Accepted: 10/03/2022] [Indexed: 12/14/2022]
Abstract
Sensitivity to the earth's magnetic field is the least understood of the major sensory systems, despite being virtually ubiquitous in animals and of widespread interest to investigators in a wide range of fields from behavioral ecology to quantum physics. Although research on the use of magnetic cues by migratory birds, fish, and sea turtles is more widely known, much of our current understanding of the functional properties of vertebrate magnetoreception has come from research on amphibians. Studies of amphibians established the presence of a light-dependent magnetic compass, a second non-light-dependent mechanism involving particles of magnetite and/or maghemite, and an interaction between these two magnetoreception mechanisms that underlies the "map" component of homing. Simulated magnetic displacement experiments demonstrated the use of a high-resolution magnetic map for short-range homing to breeding ponds requiring a sampling strategy to detect weak spatial gradients in the magnetic field despite daily temporal variation at least an order of magnitude greater. Overall, reliance on a magnetic map for short-range homing places greater demands on the underlying sensory detection, processing, and memory mechanisms than comparable mechanisms used by long-distance migrants. Moreover, unlike sea turtles and migratory birds, amphibians are exceptionally well suited to serve as model organisms in which to characterize the molecular and biophysical mechanisms underlying the light-dependent 'quantum compass'.
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3
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Chetverikova R, Dautaj G, Schwigon L, Dedek K, Mouritsen H. Double cones in the avian retina form an oriented mosaic which might facilitate magnetoreception and/or polarized light sensing. J R Soc Interface 2022; 19:20210877. [PMID: 35414212 PMCID: PMC9006000 DOI: 10.1098/rsif.2021.0877] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
To navigate between breeding and wintering grounds, night-migratory songbirds are aided by a light-dependent magnetic compass sense and maybe also by polarized light vision. Although the underlying mechanisms for magnetoreception and polarized light sensing remain unclear, double cone photoreceptors in the avian retina have been suggested to represent the primary sensory cells. To use these senses, birds must be able to separate the directional information from the Earth's magnetic field and/or light polarization from variations in light intensity. Theoretical considerations suggest that this could be best achieved if neighbouring double cones were oriented in an ordered pattern. Therefore, we investigate the orientation patterns of double cones in European robins (Erithacus rubecula) and domestic chickens (Gallus gallus domesticus). We used whole-mounted retinas labelled with double cone markers to quantify the orientations of individual double cones in relation to their nearest neighbours. In both species, our data show that the double cone array is highly ordered: the angles between neighbouring double cones were more likely to be 90°/-90° in the central retina and 180°/0° in the peripheral retina, respectively. The observed regularity in double cone orientation could aid the cells' putative function in light-dependent magnetoreception and/or polarized light sensing.
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Affiliation(s)
- Raisa Chetverikova
- Animal Navigation/Neurosensorics Group, Institute for Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany
| | - Glen Dautaj
- Animal Navigation/Neurosensorics Group, Institute for Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany
| | - Leonard Schwigon
- Animal Navigation/Neurosensorics Group, Institute for Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany
| | - Karin Dedek
- Animal Navigation/Neurosensorics Group, Institute for Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany.,Research Center Neurosensory Science, University of Oldenburg, Oldenburg, Germany
| | - Henrik Mouritsen
- Animal Navigation/Neurosensorics Group, Institute for Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany.,Research Center Neurosensory Science, University of Oldenburg, Oldenburg, Germany
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4
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Anthropogenic Illumination as Guiding Light for Nocturnal Bird Migrants Identified by Remote Sensing. REMOTE SENSING 2022. [DOI: 10.3390/rs14071616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Migrant birds rely on environmental and celestial cues for navigation and orientation during their journeys. Adverse weather, such as heavy rain or fog, but also thick layers of low-level clouds, affect visibility and can challenge birds’ ability to orientate. Therefore, birds typically favour certain meteorological conditions for migration. Photopollution from artificial lights outdoors and radiated from buildings is known to negatively affect nocturnal migrants’ flight behaviour and trajectories, which may lead to collisions with human infrastructure. Positive effects of artificial light have been identified in some stationary birds, e.g., for extended foraging hours, though not during migration. In the present study, we show the effect of artificial light on the concentration and flight directions of migrating birds during overcast conditions in the peri-urban woodland in Southern Finland. Overcast conditions, by low-level clouds, prompted birds to migrate at low altitudes. Instead of spatially homogenous large-scale migration patterns, birds were observed to adapt their flight directions, in accordance with the artificial lights of the urbanized area. By using dual- and single-polarisation weather radar data we were able to study small-scale patterns of bird movements under the influence of low-level cloud layers. These cases show the remarkable capability of the existing weather radar networks to study bird migration.
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5
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Phillips J, Muheim R, Painter M, Raines J, Anderson C, Landler L, Dommer D, Raines A, Deutschlander M, Whitehead J, Fitzpatrick NE, Youmans P, Borland C, Sloan K, McKenna K. Why is it so difficult to study magnetic compass orientation in murine rodents? J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2022; 208:197-212. [PMID: 35094127 DOI: 10.1007/s00359-021-01532-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 11/30/2021] [Accepted: 12/03/2021] [Indexed: 01/21/2023]
Abstract
A magnetic compass sense has been demonstrated in all major classes of vertebrates, as well as in many invertebrates. In mammals, controlled laboratory studies of mice have provided evidence for a robust magnetic compass that is comparable to, or exceeds, the performance of that in other animals. Nevertheless, the vast majority of laboratory studies of spatial behavior and cognition in murine rodents have failed to produce evidence of sensitivity to magnetic cues. Given the central role that a magnetic compass sense plays in the spatial ecology and cognition of non-mammalian vertebrates, and the potential utility that a global/universal reference frame derived from the magnetic field would have in mammals, the question of why responses to magnetic cues have been so difficult to demonstrate reliably is of considerable importance. In this paper, we review evidence that the magnetic compass of murine rodents shares a number of properties with light-dependent compasses in a wide variety of other animals generally believed to be mediated by a radical pair mechanism (RPM) or related quantum process. Consistent with the RPM, we summarize both published and previously unpublished findings suggesting that the murine rodent compass is sensitive to low-level radio frequency (RF) fields. Finally, we argue that the presence of anthropogenic RF fields in laboratory settings, may be an important source of variability in responses of murine rodents to magnetic cues.
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Affiliation(s)
- John Phillips
- Dept of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061-0406, USA.
| | - Rachel Muheim
- Dept of Biology, Lund University, Biology Building, 223 62, Lund, Sweden
| | - Michael Painter
- Dept of Biology, Barry University, 11300 NE 2nd Ave, Miami, FL, 33161, USA
| | - Jenny Raines
- University of Virginia, 409 Lane Road, Charlottesville, VA, 22908, USA
| | - Chris Anderson
- Electrical Engineering Dept, US Naval Academy, 105 Maryland Ave, Annapolis, MD, 21402, USA
| | - Lukas Landler
- Institute of Zoology, University of Natural Resources and Life Sciences (BOKU), Gregor-Mendel-Straße 33/I, 1180, Vienna, Austria
| | - Dave Dommer
- University of Mount Olive, 5001 South Miami Boulevard, Durham, NC, 27703, USA
| | - Adam Raines
- Dept of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061-0406, USA
| | - Mark Deutschlander
- Dept of Biology, Hobart and William Smith Colleges, 300 Pulteney St., Geneva, NY, 14456, USA
| | - John Whitehead
- Dept of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061-0406, USA
| | | | - Paul Youmans
- Dept of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061-0406, USA
| | - Chris Borland
- Civic Champs, 642 N. Madison St., Suite 116, Bloomington, IN, 47404, USA
| | - Kelly Sloan
- Sanibel Captiva Conservation Foundation, 3333 Sanibel Captiva Rd, PO Box 839, Sanibel, FL, 33957, USA
| | - Kaitlyn McKenna
- Dept of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061-0406, USA
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Netušil R, Tomanová K, Chodáková L, Chvalová D, Doležel D, Ritz T, Vácha M. Cryptochrome-dependent magnetoreception in a heteropteran insect continues even after 24 h in darkness. J Exp Biol 2021; 224:272037. [PMID: 34477876 DOI: 10.1242/jeb.243000] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 08/26/2021] [Indexed: 11/20/2022]
Abstract
Sensitivity to magnetic fields is dependent on the intensity and color of light in several animal species. The light-dependent magnetoreception working model points to cryptochrome (Cry) as a protein cooperating with its co-factor flavin, which possibly becomes magnetically susceptible upon excitation by light. The type of Cry involved and what pair of magnetosensitive radicals are responsible is still elusive. Therefore, we developed a conditioning assay for the firebug Pyrrhocoris apterus, an insect species that possesses only the mammalian cryptochrome (Cry II). Here, using the engineered Cry II null mutant, we show that: (i) vertebrate-like Cry II is an essential component of the magnetoreception response, and (ii) magnetic conditioning continues even after 25 h in darkness. The light-dependent and dark-persisting magnetoreception based on Cry II may inspire new perspectives in magnetoreception and cryptochrome research.
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Affiliation(s)
- Radek Netušil
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno 62500, Czech Republic
| | - Kateřina Tomanová
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno 62500, Czech Republic
| | - Lenka Chodáková
- Biology Centre of the Czech Academy of Sciences, České Budějovice 37005, Czech Republic
| | - Daniela Chvalová
- Biology Centre of the Czech Academy of Sciences, České Budějovice 37005, Czech Republic
| | - David Doležel
- Biology Centre of the Czech Academy of Sciences, České Budějovice 37005, Czech Republic
| | - Thorsten Ritz
- Department of Physics and Astronomy, University of California Irvine, Irvine, CA 92697, USA
| | - Martin Vácha
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno 62500, Czech Republic
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7
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Kashetsky T, Avgar T, Dukas R. The Cognitive Ecology of Animal Movement: Evidence From Birds and Mammals. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.724887] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Cognition, defined as the processes concerned with the acquisition, retention and use of information, underlies animals’ abilities to navigate their local surroundings, embark on long-distance seasonal migrations, and socially learn information relevant to movement. Hence, in order to fully understand and predict animal movement, researchers must know the cognitive mechanisms that generate such movement. Work on a few model systems indicates that most animals possess excellent spatial learning and memory abilities, meaning that they can acquire and later recall information about distances and directions among relevant objects. Similarly, field work on several species has revealed some of the mechanisms that enable them to navigate over distances of up to several thousand kilometers. Key behaviors related to movement such as the choice of nest location, home range location and migration route are often affected by parents and other conspecifics. In some species, such social influence leads to the formation of aggregations, which in turn may lead to further social learning about food locations or other resources. Throughout the review, we note a variety of topics at the interface of cognition and movement that invite further investigation. These include the use of social information embedded in trails, the likely important roles of soundscapes and smellscapes, the mechanisms that large mammals rely on for long-distance migration, and the effects of expertise acquired over extended periods.
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8
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Pinzon-Rodriguez A, Muheim R. Cryptochrome expression in avian UV cones: revisiting the role of CRY1 as magnetoreceptor. Sci Rep 2021; 11:12683. [PMID: 34135416 PMCID: PMC8209128 DOI: 10.1038/s41598-021-92056-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 06/03/2021] [Indexed: 02/05/2023] Open
Abstract
Cryptochromes (CRY) have been proposed as putative magnetoreceptors in vertebrates. Localisation of CRY1 in the UV cones in the retinas of birds suggested that it could be the candidate magnetoreceptor. However, recent findings argue against this possibility. CRY1 is a type II cryptochrome, a subtype of cryptochromes that may not be inherently photosensitive, and it exhibits a clear circadian expression in the retinas of birds. Here, we reassessed the localisation and distribution of CRY1 in the retina of the zebra finch. Zebra finches have a light-dependent magnetic compass based on a radical-pair mechanism, similar to migratory birds. We found that CRY1 colocalised with the UV/V opsin (SWS1) in the outer segments of UV cones, but restricted to the tip of the segments. CRY1 was found in all UV cones across the entire retina, with the highest densities near the fovea. Pre-exposure of birds to different wavelengths of light did not result in any difference in CRY1 detection, suggesting that CRY1 did not undergo any detectable functional changes as result of light activation. Considering that CRY1 is likely not involved in magnetoreception, our findings open the possibility for an involvement in different, yet undetermined functions in the avian UV/V cones.
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Affiliation(s)
- Atticus Pinzon-Rodriguez
- grid.4514.40000 0001 0930 2361Department of Biology, Lund University, Biology Building B, 223 62 Lund, Sweden
| | - Rachel Muheim
- grid.4514.40000 0001 0930 2361Department of Biology, Lund University, Biology Building B, 223 62 Lund, Sweden
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9
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Abstract
Species throughout the animal kingdom use the Earth's magnetic field (MF) to navigate using either or both of two mechanisms. The first relies on magnetite crystals in tissue where their magnetic moments align with the MF to transduce a signal transmitted to the central nervous system. The second and the subject of this paper involves cryptochrome (CRY) proteins located in cone photoreceptors distributed across the retina, studied most extensively in birds. According to the "Radical Pair Mechanism" (RPM), blue/UV light excites CRY's flavin cofactor (FAD) to generate radical pairs whose singlet-to-triplet interconversion rate is modulated by an external MF. The signaling product of the RPM produces an impression of the field across the retinal surface. In birds, the resulting signal on the optic nerve is transmitted along the thalamofugal pathway to the primary visual cortex, which projects to brain regions concerned with image processing, memory, and executive function. The net result is a bird's orientation to the MF's inclination: its vector angle relative to the Earth's surface. The quality of ambient light (e.g., polarization) provides additional input to the compass. In birds, the Type IV CRY isoform appears pivotal to the compass, given its positioning within retinal cones; a cytosolic location therein indicating no role in the circadian clock; relatively steady diurnal levels (unlike Type II CRY's cycling); and a full complement of FAD (essential for photosensitivity). The evidence indicates that mammalian Type II CRY isoforms play a light-independent role in the cellular molecular clock without a photoreceptive function.
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Affiliation(s)
| | - Joseph Brain
- Environmental Physiology, Molecular, and Integrative Physiological Sciences Program, Department of Environmental Health, Harvard T. H. Chan School of Public Health, Boston, Massachusetts
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10
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Pail M, Landler L, Gollmann G. Orientation and navigation in Bufo bufo: a quest for repeatability of arena experiments. HERPETOZOA 2020; 33:139-147. [PMID: 35444377 PMCID: PMC7612639 DOI: 10.3897/herpetozoa.33.e52854] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Research on navigation in animals is hampered by conflicting results and failed replications. In order to assess the generality of previous results, male Bufo bufo were collected during their breeding migration and translocated to two testing sites, 2.4 and 2.9 km away, respectively, from their breeding pond in the north of Vienna (Austria). There each toad was tested twice for orientation responses in a circular arena, on the night of collection and four days later. On the first test day, the toads showed significant axial orientation along their individual former migration direction. On the second test day, no significant homeward orientation was detected. Both results accord with findings of previous experiments with toads from another population. We analysed the potential influence of environmental factors (temperature, cloud cover and lunar cycle) on toad orientations using a MANOVA approach. Although cloud cover and lunar cycle had small effects on the second test day, they could not explain the absence of homeward orientation. The absence of homing responses in these tests may be either caused by the absence of navigational capabilities of toads beyond their home ranges, or by inadequacies of the applied method. To resolve this question, tracking of freely moving toads should have greater potential than the use of arena experiments.
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11
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Cabrera‐Cruz SA, Smolinsky JA, McCarthy KP, Buler JJ. Urban areas affect flight altitudes of nocturnally migrating birds. J Anim Ecol 2019; 88:1873-1887. [DOI: 10.1111/1365-2656.13075] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 07/12/2019] [Indexed: 12/27/2022]
Affiliation(s)
| | - Jaclyn A. Smolinsky
- Department of Entomology and Wildlife Ecology University of Delaware Newark DE USA
| | - Kyle P. McCarthy
- Department of Entomology and Wildlife Ecology University of Delaware Newark DE USA
| | - Jeffrey J. Buler
- Department of Entomology and Wildlife Ecology University of Delaware Newark DE USA
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12
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Abstract
Magnetic fields pass through tissue undiminished and without producing harmful effects, motivating their use as a wireless, minimally invasive means to control neural activity. Here, we review mechanisms and techniques coupling magnetic fields to changes in electrochemical potentials across neuronal membranes. Biological magnetoreception, although incompletely understood, is discussed as a potential source of inspiration. The emergence of magnetic properties in materials is reviewed to clarify the distinction between biomolecules containing transition metals and ferrite nanoparticles that exhibit significant net moments. We describe recent developments in the use of magnetic nanomaterials as transducers converting magnetic stimuli to forms readily perceived by neurons and discuss opportunities for multiplexed and bidirectional control as well as the challenges posed by delivery to the brain. The variety of magnetic field conditions and mechanisms by which they can be coupled to neuronal signaling cascades highlights the desirability of continued interchange between magnetism physics and neurobiology.
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Affiliation(s)
- Michael G Christiansen
- Department of Health Sciences and Technology, Swiss Federal Institute of Technology, 8093 Zürich, Switzerland
| | - Alexander W Senko
- Department of Materials Science and Engineering, Research Laboratory of Electronics, and McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA;
| | - Polina Anikeeva
- Department of Materials Science and Engineering, Research Laboratory of Electronics, and McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA;
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13
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Ectosymbionts alter spontaneous responses to the Earth's magnetic field in a crustacean. Sci Rep 2019; 9:3105. [PMID: 30816116 PMCID: PMC6395607 DOI: 10.1038/s41598-018-38404-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 12/17/2018] [Indexed: 11/08/2022] Open
Abstract
Magnetic sensing is used to structure every-day, non-migratory behaviours in many animals. We show that crayfish exhibit robust spontaneous magnetic alignment responses. These magnetic behaviours are altered by interactions with Branchiobdellidan worms, which are obligate ectosymbionts. Branchiobdellidan worms have previously been shown to have positive effects on host growth when present at moderate densities, and negative effects at relatively high densities. Here we show that crayfish with moderate densities of symbionts aligned bimodally along the magnetic northeast-southwest axis, similar to passive magnetic alignment responses observed across a range of stationary vertebrates. In contrast, crayfish with high symbiont densities failed to exhibit consistent alignment relative to the magnetic field. Crayfish without symbionts shifted exhibited quadramodal magnetic alignment and were more active. These behavioural changes suggest a change in the organization of spatial behaviour with increasing ectosymbiont densities. We propose that the increased activity and a switch to quadramodal magnetic alignment may be associated with the use of systematic search strategies. Such a strategy could increase contact-rates with conspecifics in order to replenish the beneficial ectosymbionts that only disperse between hosts during direct contact. Our results demonstrate that crayfish perceive and respond to magnetic fields, and that symbionts influence magnetically structured spatial behaviour of their hosts.
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14
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Robertson BA, Horváth G. Color polarization vision mediates the strength of an evolutionary trap. Evol Appl 2019; 12:175-186. [PMID: 30697332 PMCID: PMC6346644 DOI: 10.1111/eva.12690] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Revised: 07/19/2018] [Accepted: 07/20/2018] [Indexed: 11/28/2022] Open
Abstract
Evolutionary traps are scenarios in which animals are fooled by rapidly changing conditions into preferring poor-quality resources over those that better improve survival and reproductive success. The maladaptive attraction of aquatic insects to artificial sources of horizontally polarized light (e.g., glass buildings, asphalt roads) has become a first model system by which scientists can investigate the behavioral mechanisms that cause traps to occur. We employ this field-based system to experimentally investigate (a) in which portion(s) of the spectrum are polarizationally water-imitating reflectors attractive to nocturnal terrestrial and aquatics insects, and (b) which modern lamp types result in greater attraction in this typical kind of nocturnal polarized light pollution. We found that most aquatic taxa exhibited preferences for lamps based upon their color spectra, most having lowest preference for lamps emitting blue and red light. Yet, despite previously established preference for higher degrees of polarization of reflected light, most aquatic insect families were attracted to traps based upon their unpolarized spectrum. Chironomid midges, alone, showed a preference for the color of lamplight in both the horizontally polarized and unpolarized spectra indicating only this family has evolved to use light in this color range as a source of information to guide its nocturnal habitat selection. These results demonstrate that the color of artificial lighting can exacerbate or reduce its attractiveness to aquatic insects, but that the strength of attractiveness of nocturnal evolutionary traps, and so their demographic consequences, is primarily driven by unpolarized light pollution. This focuses management attention on limiting broad-spectrum light pollution, as well as its intentional deployment to attract insects back to natural habitats.
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Affiliation(s)
- Bruce A. Robertson
- Division of Science, Mathematics and ComputingBard CollegeAnnandale‐on‐HudsonNew York
| | - Gábor Horváth
- Environmental Optics LaboratoryDepartment of Biological Physics, Physical InstituteELTE Eötvös Loránd UniversityBudapestHungary
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15
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Ilieva M, Bianco G, Åkesson S. Effect of geomagnetic field on migratory activity in a diurnal passerine migrant, the dunnock, Prunella modularis. Anim Behav 2018. [DOI: 10.1016/j.anbehav.2018.10.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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16
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Nießner C, Denzau S, Peichl L, Wiltschko W, Wiltschko R. Magnetoreception: activation of avian cryptochrome 1a in various light conditions. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2018; 204:977-984. [DOI: 10.1007/s00359-018-1296-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Revised: 07/26/2018] [Accepted: 09/26/2018] [Indexed: 12/24/2022]
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17
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Abstract
Over the last three decades, evidence has emerged that low-intensity magnetic fields can influence biological systems. It is now well established that migratory birds have the capacity to detect the Earth's magnetic field; it has been reported that power lines are associated with childhood leukemia and that pulsed magnetic fields increase the production of reactive oxidative species (ROS) in cellular systems. Justifiably, studies in this field have been viewed with skepticism, as the underlying molecular mechanisms are unknown. In the accompanying paper, Sherrard and colleagues report that low-flux pulsed electromagnetic fields (PEMFs) result in aversive behavior in Drosophila larvae and ROS production in cell culture. They further report that these responses require the presence of cryptochrome, a putative magnetoreceptor. If correct, it is conceivable that carcinogenesis associated with power lines, PEMF-induced ROS generation, and animal magnetoreception share a common mechanistic basis.
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Affiliation(s)
- Lukas Landler
- Research Institute of Molecular Pathology, Vienna Biocentre, Vienna, Austria
| | - David A. Keays
- Research Institute of Molecular Pathology, Vienna Biocentre, Vienna, Austria
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18
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Worster S, Mouritsen H, Hore PJ. A light-dependent magnetoreception mechanism insensitive to light intensity and polarization. J R Soc Interface 2018; 14:rsif.2017.0405. [PMID: 28878033 DOI: 10.1098/rsif.2017.0405] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 08/11/2017] [Indexed: 11/12/2022] Open
Abstract
Billions of migratory birds navigate thousands of kilometres every year aided by a magnetic compass sense, the biophysical mechanism of which is unclear. One leading hypothesis is that absorption of light by specialized photoreceptors in the retina produces short-lived chemical intermediates known as radical pairs whose chemistry is sensitive to tiny magnetic interactions. A potentially serious but largely ignored obstacle to this theory is how directional information derived from the Earth's magnetic field can be separated from the much stronger variations in the intensity and polarization of the incident light. Here we propose a simple solution in which these extraneous effects are cancelled by taking the ratio of the signals from two neighbouring populations of magnetoreceptors. Geometric and biological arguments are used to derive a set of conditions that make this possible. We argue that one likely location of the magnetoreceptor molecules would be in association with ordered opsin dimers in the membrane discs of the outer segments of double-cone photoreceptor cells.
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Affiliation(s)
- Susannah Worster
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK
| | - Henrik Mouritsen
- Institut für Biologie und Umweltwissenschaften, Carl von Ossietzky Universität Oldenburg, 26111 Oldenburg, Germany.,Research Centre for Neurosensory Sciences, University of Oldenburg, 26111 Oldenburg, Germany
| | - P J Hore
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK
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Vidal-Gadea A, Bainbridge C, Clites B, Palacios BE, Bakhtiari L, Gordon V, Pierce-Shimomura J. Response to comment on "Magnetosensitive neurons mediate geomagnetic orientation in Caenorhabditis elegans". eLife 2018; 7:31414. [PMID: 29651982 PMCID: PMC5898907 DOI: 10.7554/elife.31414] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 03/19/2018] [Indexed: 01/26/2023] Open
Abstract
Many animals can orient using the earth’s magnetic field. In a recent study, we performed three distinct behavioral assays providing evidence that the nematode Caenorhabditis elegans orients to earth-strength magnetic fields (Vidal-Gadea et al., 2015). A new study by Landler et al. suggests that C. elegans does not orient to magnetic fields (Landler et al., 2018). They also raise conceptual issues that cast doubt on our study. Here, we explain how they appear to have missed positive results in part by omitting controls and running assays longer than prescribed, so that worms switched their preferred migratory direction within single tests. We also highlight differences in experimental methods and interpretations that may explain our different results and conclusions. Together, these findings provide guidance on how to achieve robust magnetotaxis and reinforce our original finding that C. elegans is a suitable model system to study magnetoreception.
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Affiliation(s)
- Andres Vidal-Gadea
- School of Biological Sciences, Illinois State University, Normal, United States
| | - Chance Bainbridge
- School of Biological Sciences, Illinois State University, Normal, United States
| | - Ben Clites
- Department of Physics, University of Texas at Austin, Austin, United States
| | - Bridgitte E Palacios
- Department of Physics, University of Texas at Austin, Austin, United States.,Department of Neuroscience, University of Texas at Austin, Austin, United States
| | - Layla Bakhtiari
- Department of Neuroscience, University of Texas at Austin, Austin, United States
| | - Vernita Gordon
- Department of Neuroscience, University of Texas at Austin, Austin, United States
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20
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Pinzon-Rodriguez A, Bensch S, Muheim R. Expression patterns of cryptochrome genes in avian retina suggest involvement of Cry4 in light-dependent magnetoreception. J R Soc Interface 2018; 15:20180058. [PMID: 29593090 PMCID: PMC5908540 DOI: 10.1098/rsif.2018.0058] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 03/05/2018] [Indexed: 12/23/2022] Open
Abstract
The light-dependent magnetic compass of birds provides orientation information about the spatial alignment of the geomagnetic field. It is proposed to be located in the avian retina, and be mediated by a light-induced, biochemical radical-pair mechanism involving cryptochromes as putative receptor molecules. At the same time, cryptochromes are known for their role in the negative feedback loop in the circadian clock. We measured gene expression of Cry1, Cry2 and Cry4 in the retina, muscle and brain of zebra finches over the circadian day to assess whether they showed any circadian rhythmicity. We hypothesized that retinal cryptochromes involved in magnetoreception should be expressed at a constant level over the circadian day, because birds use a light-dependent magnetic compass for orientation not only during migration, but also for spatial orientation tasks in their daily life. Cryptochromes serving in circadian tasks, on the other hand, are expected to be expressed in a rhythmic (circadian) pattern. Cry1 and Cry2 displayed a daily variation in the retina as expected for circadian clock genes, while Cry4 expressed at constant levels over time. We conclude that Cry4 is the most likely candidate magnetoreceptor of the light-dependent magnetic compass in birds.
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Affiliation(s)
| | - Staffan Bensch
- Department of Biology, Lund University, Ecology Building, Lund 223 62, Sweden
| | - Rachel Muheim
- Department of Biology, Lund University, Biology Building B, Lund 223 62, Sweden
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21
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Wang Y, Chu J, Zhang R, Shi C. Orthogonal vector algorithm to obtain the solar vector using the single-scattering Rayleigh model. APPLIED OPTICS 2018; 57:594-601. [PMID: 29400721 DOI: 10.1364/ao.57.000594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 12/30/2017] [Indexed: 06/07/2023]
Abstract
Information obtained from a polarization pattern in the sky provides many animals like insects and birds with vital long-distance navigation cues. The solar vector can be derived from the polarization pattern using the single-scattering Rayleigh model. In this paper, an orthogonal vector algorithm, which utilizes the redundancy of the single-scattering Rayleigh model, is proposed. We use the intersection angles between the polarization vectors as the main criteria in our algorithm. The assumption that all polarization vectors can be considered coplanar is used to simplify the three-dimensional (3D) problem with respect to the polarization vectors in our simulation. The surface-normal vector of the plane, which is determined by the polarization vectors after translation, represents the solar vector. Unfortunately, the two-directionality of the polarization vectors makes the resulting solar vector ambiguous. One important result of this study is, however, that this apparent disadvantage has no effect on the complexity of the algorithm. Furthermore, two other universal least-squares algorithms were investigated and compared. A device was then constructed, which consists of five polarized-light sensors as well as a 3D attitude sensor. Both the simulation and experimental data indicate that the orthogonal vector algorithms, if used with a suitable threshold, perform equally well or better than the other two algorithms. Our experimental data reveal that if the intersection angles between the polarization vectors are close to 90°, the solar-vector angle deviations are small. The data also support the assumption of coplanarity. During the 51 min experiment, the mean of the measured solar-vector angle deviations was about 0.242°, as predicted by our theoretical model.
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22
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McLaren JD, Buler JJ, Schreckengost T, Smolinsky JA, Boone M, Emiel van Loon E, Dawson DK, Walters EL. Artificial light at night confounds broad-scale habitat use by migrating birds. Ecol Lett 2018; 21:356-364. [PMID: 29316091 DOI: 10.1111/ele.12902] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 08/14/2017] [Accepted: 11/22/2017] [Indexed: 11/28/2022]
Abstract
With many of the world's migratory bird populations in alarming decline, broad-scale assessments of responses to migratory hazards may prove crucial to successful conservation efforts. Most birds migrate at night through increasingly light-polluted skies. Bright light sources can attract airborne migrants and lead to collisions with structures, but might also influence selection of migratory stopover habitat and thereby acquisition of food resources. We demonstrate, using multi-year weather radar measurements of nocturnal migrants across the northeastern U.S., that autumnal migrant stopover density increased at regional scales with proximity to the brightest areas, but decreased within a few kilometers of brightly-lit sources. This finding implies broad-scale attraction to artificial light while airborne, impeding selection for extensive forest habitat. Given that high-quality stopover habitat is critical to successful migration, and hindrances during migration can decrease fitness, artificial lights present a potentially heightened conservation concern for migratory bird populations.
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Affiliation(s)
- James D McLaren
- Department of Entomology and Wildlife Ecology, University of Delaware, Newark, DE, 19716, USA.,National Wildlife Research Centre, Environment and Climate Change Canada, Ottawa, ON, K1A 0H3, Canada
| | - Jeffrey J Buler
- Department of Entomology and Wildlife Ecology, University of Delaware, Newark, DE, 19716, USA
| | - Tim Schreckengost
- Department of Entomology and Wildlife Ecology, University of Delaware, Newark, DE, 19716, USA
| | - Jaclyn A Smolinsky
- Department of Entomology and Wildlife Ecology, University of Delaware, Newark, DE, 19716, USA
| | - Matthew Boone
- Department of Entomology and Wildlife Ecology, University of Delaware, Newark, DE, 19716, USA
| | - E Emiel van Loon
- Theoretical and Computational Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, NL-1090 GE, Amsterdam, the Netherlands
| | - Deanna K Dawson
- U.S. Geological Survey, Patuxent Wildlife Research Center, Laurel, MD, 20708, USA
| | - Eric L Walters
- Department of Biological Sciences, Old Dominion University, Norfolk, VA, 23529, USA
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23
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Čapek F, Průcha J, Socha V, Hart V, Burda H. Directional orientation of pheasant chicks at the drinking dish and its potential for research on avian magnetoreception. FOLIA ZOOLOGICA 2017. [DOI: 10.25225/fozo.v66.i3.a5.2017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- František Čapek
- Department of Game Management and Wildlife Biology, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, 165 21 Praha 6, Czech Republic
| | - Jaroslav Průcha
- Faculty of Biomedical Engineering, Czech Technical University in Prague, 166 36 Praha 6, Czech Republic
| | - Vladimír Socha
- Faculty of Biomedical Engineering, Czech Technical University in Prague, 166 36 Praha 6, Czech Republic
| | - Vlastimil Hart
- Department of Game Management and Wildlife Biology, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, 165 21 Praha 6, Czech Republic
| | - Hynek Burda
- Department of Game Management and Wildlife Biology, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, 165 21 Praha 6, Czech Republic
- Department of General Zoology, Faculty of Biology, University Duisburg-Essen, 451 17 Essen, Germany
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24
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La Sorte FA, Fink D, Buler JJ, Farnsworth A, Cabrera-Cruz SA. Seasonal associations with urban light pollution for nocturnally migrating bird populations. GLOBAL CHANGE BIOLOGY 2017; 23:4609-4619. [PMID: 28695706 DOI: 10.1111/gcb.13792] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 06/03/2017] [Indexed: 06/07/2023]
Abstract
The spatial extent and intensity of artificial light at night (ALAN) has increased worldwide through the growth of urban environments. There is evidence that nocturnally migrating birds are attracted to ALAN, and there is evidence that nocturnally migrating bird populations are more likely to occur in urban areas during migration, especially in the autumn. Here, we test if urban sources of ALAN are responsible, at least in part, for these observed urban associations. We use weekly estimates of diurnal occurrence and relative abundance for 40 nocturnally migrating bird species that breed in forested environments in North America to assess how associations with distance to urban areas and ALAN are defined across the annual cycle. Migratory bird populations presented stronger than expected associations with shorter distances to urban areas during migration, and stronger than expected association with higher levels of ALAN outside and especially within urban areas during migration. These patterns were more pronounced during autumn migration, especially within urban areas. Outside of the two migration periods, migratory bird populations presented stronger than expected associations with longer distances to urban areas, especially during the nonbreeding season, and weaker than expected associations with the highest levels of ALAN outside and especially within urban areas. These findings suggest that ALAN is associated with higher levels of diurnal abundance along the boundaries and within the interior of urban areas during migration, especially in the autumn when juveniles are undertaking their first migration journey. These findings support the conclusion that urban sources of ALAN can broadly effect migratory behavior, emphasizing the need to better understand the implications of ALAN for migratory bird populations.
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Affiliation(s)
- Frank A La Sorte
- Cornell Laboratory of Ornithology, Cornell University, Ithaca, NY, USA
| | - Daniel Fink
- Cornell Laboratory of Ornithology, Cornell University, Ithaca, NY, USA
| | - Jeffrey J Buler
- Department of Entomology and Wildlife Ecology, University of Delaware, Newark, DE, USA
| | - Andrew Farnsworth
- Cornell Laboratory of Ornithology, Cornell University, Ithaca, NY, USA
| | - Sergio A Cabrera-Cruz
- Department of Entomology and Wildlife Ecology, University of Delaware, Newark, DE, USA
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25
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Van Doren BM, Horton KG, Dokter AM, Klinck H, Elbin SB, Farnsworth A. High-intensity urban light installation dramatically alters nocturnal bird migration. Proc Natl Acad Sci U S A 2017; 114:11175-11180. [PMID: 28973942 PMCID: PMC5651764 DOI: 10.1073/pnas.1708574114] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Billions of nocturnally migrating birds move through increasingly photopolluted skies, relying on cues for navigation and orientation that artificial light at night (ALAN) can impair. However, no studies have quantified avian responses to powerful ground-based light sources in urban areas. We studied effects of ALAN on migrating birds by monitoring the beams of the National September 11 Memorial & Museum's "Tribute in Light" in New York, quantifying behavioral responses with radar and acoustic sensors and modeling disorientation and attraction with simulations. This single light source induced significant behavioral alterations in birds, even in good visibility conditions, in this heavily photopolluted environment, and to altitudes up to 4 km. We estimate that the installation influenced ≈1.1 million birds during our study period of 7 d over 7 y. When the installation was illuminated, birds aggregated in high densities, decreased flight speeds, followed circular flight paths, and vocalized frequently. Simulations revealed a high probability of disorientation and subsequent attraction for nearby birds, and bird densities near the installation exceeded magnitudes 20 times greater than surrounding baseline densities during each year's observations. However, behavioral disruptions disappeared when lights were extinguished, suggesting that selective removal of light during nights with substantial bird migration is a viable strategy for minimizing potentially fatal interactions among ALAN, structures, and birds. Our results also highlight the value of additional studies describing behavioral patterns of nocturnally migrating birds in powerful lights in urban areas as well as conservation implications for such lighting installations.
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Affiliation(s)
- Benjamin M Van Doren
- Information Science Program, Cornell Lab of Ornithology, Ithaca, NY 14850
- Edward Grey Institute, Department of Zoology, University of Oxford, Oxford, OX1 3PS, United Kingdom
| | - Kyle G Horton
- Information Science Program, Cornell Lab of Ornithology, Ithaca, NY 14850
- Department of Biology, University of Oklahoma, Norman, OK 73019
- Oklahoma Biological Survey, University of Oklahoma, Norman, OK 73019
| | - Adriaan M Dokter
- Information Science Program, Cornell Lab of Ornithology, Ithaca, NY 14850
| | - Holger Klinck
- Bioacoustics Research Program, Cornell Lab of Ornithology, Ithaca, NY 14850
| | | | - Andrew Farnsworth
- Information Science Program, Cornell Lab of Ornithology, Ithaca, NY 14850;
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26
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Pinzon-Rodriguez A, Muheim R. Zebra finches have a light-dependent magnetic compass similar to migratory birds. J Exp Biol 2017; 220:1202-1209. [DOI: 10.1242/jeb.148098] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 01/10/2017] [Indexed: 12/24/2022]
Abstract
ABSTRACT
Birds have a light-dependent magnetic compass that provides information about the spatial alignment of the geomagnetic field. It is proposed to be located in the avian retina and mediated by a light-induced, radical-pair mechanism involving cryptochromes as sensory receptor molecules. To investigate how the behavioural responses of birds under different light spectra match with cryptochromes as the primary magnetoreceptor, we examined the spectral properties of the magnetic compass in zebra finches. We trained birds to relocate a food reward in a spatial orientation task using magnetic compass cues. The birds were well oriented along the trained magnetic compass axis when trained and tested under low-irradiance 521 nm green light. In the presence of a 1.4 MHz radio-frequency electromagnetic (RF)-field, the birds were disoriented, which supports the involvement of radical-pair reactions in the primary magnetoreception process. Birds trained and tested under 638 nm red light showed a weak tendency to orient ∼45 deg clockwise of the trained magnetic direction. Under low-irradiance 460 nm blue light, they tended to orient along the trained magnetic compass axis, but were disoriented under higher irradiance light. Zebra finches trained and tested under high-irradiance 430 nm indigo light were well oriented along the trained magnetic compass axis, but disoriented in the presence of a RF-field. We conclude that magnetic compass responses of zebra finches are similar to those observed in nocturnally migrating birds and agree with cryptochromes as the primary magnetoreceptor, suggesting that light-dependent, radical-pair-mediated magnetoreception is a common property for all birds, including non-migratory species.
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Affiliation(s)
| | - Rachel Muheim
- Department of Biology, Lund University, Biology Building B, Lund 223 62, Sweden
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27
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Xu J, Pan W, Zhang Y, Li Y, Wan G, Chen F, Sword GA, Pan W. Behavioral evidence for a magnetic sense in the oriental armyworm, Mythimna separata. Biol Open 2017; 6:340-347. [PMID: 28126710 PMCID: PMC5374402 DOI: 10.1242/bio.022954] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Progress has been made in understanding the mechanisms underlying directional navigation in migratory insects, yet the magnetic compass involved has not been fully elucidated. Here we developed a flight simulation system to study the flight directionality of the migratory armyworm Mythimna separata in response to magnetic fields. Armyworm moths were exposed to either a 500 nT extreme weak magnetic field, 1.8 T strong magnetic field, or a deflecting magnetic field and subjected to tethered flight trials indoors in the dark. The moths were disoriented in the extreme weak magnetic field, with flight vectors that were more dispersed (variance=0.60) than in the geomagnetic field (variance=0.32). After exposure to a 1.8 T strong magnetic field, the mean flight vectors were shifted by about 105° in comparison with those in the geomagnetic field. In the deflecting magnetic field, the flight directions varied with the direction of the magnetic field, and also pointed to the same direction of the magnetic field. In the south-north magnetic field and the east-west field, the flight angles were determined to be 98.9° and 166.3°, respectively, and formed the included angles of 12.66° or 6.19° to the corresponding magnetic direction. The armyworm moths responded to the change of the intensity and direction of magnetic fields. Such results provide initial indications of the moth reliance on a magnetic compass. The findings support the hypothesis of a magnetic sense used for flight orientation in the armyworm Mythimna separata. Summary: Responses to changes in the intensity and direction of magnetic fields in the armyworm moth (Mythimna separata) indicate a reliance on a magnetic compass for flight orientation.
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Affiliation(s)
- Jingjing Xu
- Beijing Key Laboratory of Bioelectromagnetics, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China.,Department of Electrical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wei Pan
- Beijing Key Laboratory of Bioelectromagnetics, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China.,Department of Electrical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yingchao Zhang
- Beijing Key Laboratory of Bioelectromagnetics, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China.,Department of Electrical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yue Li
- Beijing Key Laboratory of Bioelectromagnetics, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Guijun Wan
- Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | - Fajun Chen
- Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | - Gregory A Sword
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA
| | - Weidong Pan
- Beijing Key Laboratory of Bioelectromagnetics, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China
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28
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Li X, Liu X, Li T, Li X, Feng D, Kuang X, Xu J, Zhao X, Sun M, Chen D, Zhang Z, Feng X. SiO2 nanoparticles cause depression and anxiety-like behavior in adult zebrafish. RSC Adv 2017. [DOI: 10.1039/c6ra24215d] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Here, we report that both nano-silica (SiO2-NPs) and reserpine can elicit depression-like behavior in adult zebrafish in a novel tank test.
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29
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O’Connor J, Muheim R. Pre-settlement coral-reef fish larvae respond to magnetic field changes during the day. J Exp Biol 2017; 220:2874-2877. [DOI: 10.1242/jeb.159491] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 05/30/2017] [Indexed: 11/20/2022]
Abstract
Observations of coral-reef fish larvae have revealed remarkably consistent orientation behaviour while swimming offshore, requiring large-scale orientation cues. However, the mechanisms underlying this behaviour are still being investigated. One potential large-scale cue for orientation is the Earth’s geomagnetic field. Here, we examined the effect of magnetic field manipulations on the orientation behaviour of coral-reef fish during the pelagic larval phase. In the absence of visual cues, individual larvae responded to a 90° shift of the horizontal component of the magnetic field within a Helmholtz coil with a comparable shift in orientation, demonstrating that they use a magnetic compass for orientation. Our findings suggest that geomagnetic field information guides swimming behaviour of larval fish in the pre-settlement phase. The ability to use large-scale sensory cues allows location-independent orientation of swimming, a behaviour that influences dispersal and connectivity of fish populations, which has important ecological implications for anthropogenic development of marine areas.
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Affiliation(s)
- Jack O’Connor
- School of Life Sciences, University of Technology Sydney, Ultimo NSW 2007, Australia
| | - Rachel Muheim
- Department of Biology, Lund University, Biology Building B, 223 62 Lund, Sweden
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30
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Affiliation(s)
- P. J. Hore
- Department of Chemistry, University of Oxford, Oxford OX1 3QZ, United Kingdom;
| | - Henrik Mouritsen
- Institut für Biologie und Umweltwissenschaften, Carl von Ossietzky Universität Oldenburg, DE-26111 Oldenburg, Germany;
- Research Centre for Neurosensory Sciences, University of Oldenburg, DE-26111 Oldenburg, Germany
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