scholarly journals Magnetic orientation of garden warblers ( Sylvia borin ) under 1.4 MHz radiofrequency magnetic field

2014 ◽  
Vol 11 (97) ◽  
pp. 20140451 ◽  
Author(s):  
Kirill Kavokin ◽  
Nikita Chernetsov ◽  
Alexander Pakhomov ◽  
Julia Bojarinova ◽  
Dmitry Kobylkov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Visual Information ◽  
Magnetic Compass ◽  
Erithacus Rubecula ◽  
Garden Warbler ◽  
Independent Replication ◽  
Migratory Songbird ◽  
Sylvia Borin ◽  
Magnetic Meridian ◽  
Rf Magnetic Field

We report on the experiments on orientation of a migratory songbird, the garden warbler ( Sylvia borin ) , during the autumn migration period on the Courish Spit, Eastern Baltics. Birds in experimental cages, deprived of visual information, showed the seasonally appropriate direction of intended flight with respect to the magnetic meridian. Weak radiofrequency (RF) magnetic field (190 nT at 1.4 MHz) disrupted this orientation ability. These results may be considered as an independent replication of earlier experiments, performed by the group of R. and W. Wiltschko with European robins ( Erithacus rubecula ). Confirmed outstanding sensitivity of the birds' magnetic compass to RF fields in the lower megahertz range demands for a revision of one of the mainstream theories of magnetoreception, the radical-pair model of birds' magnetic compass.

scholarly journals Very weak oscillating magnetic field disrupts the magnetic compass of songbird migrants

2017 ◽  
Vol 14 (133) ◽  
pp. 20170364 ◽  
Author(s):  
Alexander Pakhomov ◽  
Julia Bojarinova ◽  
Roman Cherbunin ◽  
Raisa Chetverikova ◽  
Philipp S. Grigoryev ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Narrow Band ◽  
Radical Pair ◽  
Magnetic Compass ◽  
Sensitivity Threshold ◽  
Erithacus Rubecula ◽  
Long Distance ◽  
Pair Model ◽  
Oscillating Magnetic Field ◽  
Sylvia Borin

Previously, it has been shown that long-distance migrants, garden warblers ( Sylvia borin ), were disoriented in the presence of narrow-band oscillating magnetic field (1.403 MHz OMF, 190 nT) during autumn migration. This agrees with the data of previous experiments with European robins ( Erithacus rubecula ). In this study, we report the results of experiments with garden warblers tested under a 1.403 MHz OMF with various amplitudes (∼0.4, 1, ∼2.4, 7 and 20 nT). We found that the ability of garden warblers to orient in round arenas using the magnetic compass could be disrupted by a very weak oscillating field, such as an approximate 2.4, 7 and 20 nT OMF, but not by an OMF with an approximate 0.4 nT amplitude. The results of the present study indicate that the sensitivity threshold of the magnetic compass to the OMF lies around 2–3 nT, while in experiments with European robins the birds were disoriented in a 15 nT OMF but could choose the appropriate migratory direction when a 5 nT OMF was added to the stationary magnetic field. The radical-pair model, one of the mainstream theories of avian magnetoreception, cannot explain the sensitivity to such a low-intensity OMF, and therefore, it needs further refinement.

scholarly journals Comparability of Wing Length Measurements Based on Data Collected at two Twin Stations during Migration

Ring ◽  
2012 ◽  
Vol 34 (1) ◽  
pp. 37-43
Author(s):  
Grzegorz Zaniewicz
Keyword(s):  
Human Factor ◽  
Wing Length ◽  
Erithacus Rubecula ◽  
Quality Of Information ◽  
Garden Warbler ◽  
Baltic Coast ◽  
Length Measurements ◽  
Sylvia Borin ◽  
Local Variability

Abstract Zaniewicz G. 2012. Comparability of wing length measurements based on data collected attwo twin stations during migration. Ring 34: 37-43. Data collected during bird migration include measurements taken during ringing. The variety and quality of information, which these measurements can potentially provide, depend strongly on their accuracy and comparability. The analysis of the comparability was made based on the measurements of wing length taken by different ringers during autumn migratory seasons at the southern Baltic coast. An experiment was run with the measurements taken from six passerine species during several (from 8 to 10, depending on the species) migratory seasons at two twin sites belonging to Mierzeja Wioelana station. Pearson’s correlation coefficient was used to evaluate how strongly the habits of different measurers influence the measurements taken. The results of this experiment show that correlations between the measurements collected at these two sites are strong and statistically significant for the Blackcap (Sylvia atricapilla), Garden Warbler (Sylvia borin), Robin (Erithacus rubecula) and Song Thrush (Turdus philomelos). However, for the Goldcrest (Regulus regulus) and Willow Warbler (Phylloscopus trochilus) the relations were not significant. The last species allow to consider other causes, independent from human factor, which are possibly responsible for the average wing length local variability. In such species, we still need to look closer at the potential sources of their differentiation, such as the preferences of habitat selection between sexes, populations, etc.

scholarly journals Night-migratory garden warblers can orient with their magnetic compass using the left, the right or both eyes

2009 ◽  
Vol 7 (suppl_2) ◽  
Author(s):  
Christine Maira Hein ◽  
Manuela Zapka ◽  
Dominik Heyers ◽  
Sandra Kutzschbauch ◽  
Nils-Lasse Schneider ◽  
...  
Keyword(s):  
Magnetic Compass ◽  
Compass Orientation ◽  
Orientation Behaviour ◽  
Eyes Open ◽  
Magnetic Compass Orientation ◽  
Migratory Songbird ◽  
Sylvia Borin ◽  
The Right

Several studies have suggested that the magnetic compass of birds is located only in the right eye. However, here we show that night-migrating garden warblers ( Sylvia borin ) are able to perform magnetic compass orientation with both eyes open, with only the left eye open and with only the right eye open. We did not observe any clear lateralization of magnetic compass orientation behaviour in this migratory songbird, and, therefore, it seems that the suggested all-or-none lateralization of magnetic compass orientation towards the right eye only cannot be generalized to all birds, and that the answer to the question of whether magnetic compass orientation in birds is lateralized is probably not as simple as suggested previously.

The retinal circuitry for magnetoreception in migratory birds

Neuroforum ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Pranav K. Seth ◽  
Vaishnavi Balaji ◽  
Karin Dedek
Keyword(s):  
Magnetic Field ◽  
Blue Light ◽  
Visual Information ◽  
Migratory Birds ◽  
Current Knowledge ◽  
Magnetic Compass ◽  
Earth’S Magnetic Field ◽  
Retinal Circuitry ◽  
Open Questions ◽  
Avian Retina

Abstract Night-migratory birds use the Earth’s magnetic field to determine the direction in which they want to migrate. Many studies suggest that this “magnetic compass sense” is light dependent and mediated by blue light sensors, called cryptochromes, which are expressed in the retina of night-migratory birds. In this review, we summarize the evidence that the avian retina processes not only visual information but also magnetic compass information. We also review the current knowledge on cryptochrome expression in the bird retina and highlight open questions which we aim to address within the framework of SFB 1372 Magnetoreception and Navigation in Vertebrates.

scholarly journals Energy Stores, Oxidative Balance, and Sleep in Migratory Garden Warblers (Sylvia borin) and Whitethroats (Sylvia communis) at a Spring Stopover Site

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Andrea Ferretti ◽  
Scott R McWilliams ◽  
Niels C Rattenborg ◽  
Ivan Maggini ◽  
Massimiliano Cardinale ◽  
...  
Keyword(s):  
Food Intake ◽  
High Energy ◽  
Oxidative Status ◽  
Energy Reserves ◽  
Stopover Site ◽  
Garden Warbler ◽  
Oxidative Balance ◽  
Energy Stores ◽  
Sylvia Borin ◽  
Sylvia Communis

Synopsis Little is known about how songbirds modulate sleep during migratory periods. Due to the alternation of nocturnal endurance flights and diurnal refueling stopovers, sleep is likely to be a major constraint for many migratory passerine species. Sleep may help to increase the endogenous antioxidant capacity that counteracts free radicals produced during endurance flight and reduces energy expenditure. Here, we investigated the relationship between sleep behavior, food intake, and two markers of physiological condition—the amount of energy reserves and oxidative status—in two migratory songbird species, the garden warbler (Sylvia borin) and the whitethroat (Sylvia communis). In garden warblers, birds with high energy stores were more prone to sleep during the day, while this condition-dependent sleep pattern was not present in whitethroats. In both species, birds with low energy stores were more likely to sleep with their head tucked in the feathers during nocturnal sleep. Moreover, we found a positive correlation between food intake and the extent of energy reserves in garden warblers, but not in whitethroats. Finally, we did not find significant correlations between oxidative status and sleep, or oxidative status and energy stores. Despite our study was not comparative, it suggests that different species might use different strategies to manage their energy during stopover and, additionally, it raises the possibility that migrants have evolved physiological adaptations to deal with oxidative damage produced during migration.

Heating Near Implanted Medical Devices by the MRI RF-magnetic Field

1999 ◽  
Author(s):  
J.A. Nyenhuis ◽  
A.V. Kildishev ◽  
T.W. Athey ◽  
J.D. Bourland ◽  
K.S. Foster ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Medical Devices ◽  
Implanted Medical Devices ◽  
Rf Magnetic Field

Standard RF magnetic field from a rotating field generator

1986 ◽  
Vol IM-35 (3) ◽  
pp. 358-360
Author(s):  
H. Nakane ◽  
S. Omori ◽  
I. Yokoshima
Keyword(s):  
Magnetic Field ◽  
Rf Magnetic Field ◽  
Rotating Field
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