..., the avian magnetic compass becomes ambiguous, because the birds can no longer distinguish ‘to the pole’ from ‘to the equator’. Experiments with bobolinks and garden warblers have shown that these birds adaptively change their orientation when exposed to a horizontal magnetic field. We tested this in marsh...

... strategy differently. Summary: European songbird migrants do not calibrate their compass systems even if they have access to a view of the sky and stars during cue-conflict treatments. Bird migration Animal orientation and navigation Compass calibration Magnetic compass Celestial cues...

... of celestial compasses. Migratory birds can use three different compass systems to determine their migratory direction – the sun compass ( Kramer, 1952 ; Schmidt-Koenig, 1990 ), the star compass ( Emlen, 1967a , b ; Pakhomov et al., 2017 ) and the magnetic compass ( Wiltschko and Wiltschko, 1972 ; Hore...

... associated with magnetic field perception and compass calibration. Behavioural experiments Magnetic compass Magnetic sense Movement patterns Geomagnetic field Many animals are known to have a magnetic sense and to use the geomagnetic field for orientation and navigation ( Wiltschko...

...Christine Nießner; Susanne Denzau; Leo Peichl; Wolfgang Wiltschko; Roswitha Wiltschko Cryptochrome 1a, located in the UV/violet-sensitive cones in the avian retina, is discussed as receptor molecule for the magnetic compass of birds. Our previous immunohistochemical studies of chicken retinae...

... and tested again 1 week later, the chicks that had not shown a directional preference on days 5 to 7 continued to search randomly, while the chicks tested from day 8 onward preferred the correct magnetic axis when tested 1 week later. The observation that the magnetic compass is not functional before day 8...

... by the birds was measured. We found no recalibration of the magnetic compass after pre-exposure to a cue conflict between the natural magnetic field and the artificially shifted polarization pattern at sunset. The lacking difference in the departure direction of both groups may suggest that birds did...

...Roswitha Wiltschko; Susanne Denzau; Dennis Gehring; Peter Thalau; Wolfgang Wiltschko SUMMARY The avian magnetic compass is an inclination compass that appears to be based on radical pair processes. It requires light from the short-wavelength range of the spectrum up to 565 nm green light; under...

... a biophysical perspective, differ from those of a magnetite-based magnetic compass. The RPM is expected to produce a light-dependent, 3-D pattern of response that is axially symmetrical and, in some groups of animals, may be perceived as a pattern of light intensity and/or color superimposed on the visual...

...Rachel Muheim; John B. Phillips; Mark E. Deutschlander SUMMARY The interaction and hierarchy of celestial and magnetic compass cues used by migratory songbirds for orientation has long been the topic of an intense debate. We have previously shown that migratory Savannah sparrows, Passerculus...

...Roswitha Wiltschko; Ursula Munro; Hugh Ford; Katrin Stapput; Wolfgang Wiltschko SUMMARY Magnetic compass orientation in migratory birds has been shown to be based on radical pair processes and to require light from the short wavelength part of the spectrum up to 565 nm Green. Under dim red light...

...Wolfgang Wiltschko; Rafael Freire; Ursula Munro; Thorsten Ritz; Lesley Rogers; Peter Thalau; Roswitha Wiltschko SUMMARY By directional training, young domestic chickens have been shown to use a magnetic compass; the same method has now been used to analyse the functional characteristics...

... of earlier authors, our analyses suggest that during the premigratory season, celestial information is given the greatest salience and used to recalibrate the magnetic compass by both juvenile and adult birds. Sunset polarized light patterns from the region of the sky near the horizon appear to provide...

...Martin Vácha; Helena Soukopová SUMMARY There is evidence for both light-dependent and light-independent mechanisms of magnetoreception of terrestrial animals. One example of a light-independent mechanism frequently cited is the magnetic compass of the mealworm beetle( Tenebrio molitor ). We found...

...Wolfgang Wiltschko; Andrea Möller; Marcus Gesson; Catrin Noll; Roswitha Wiltschko SUMMARY In previous experiments, migratory birds had been disoriented under 635 nm red light, apparently unable to use their magnetic compass. The present study with European robins, Erithacus rubecula , confirms...

...Rachel Muheim; Johan Bäckman; Susanne Åkesson SUMMARY Magnetic compass orientation in birds has been shown to be light dependent. Results from behavioural studies indicate that magnetoreception capabilities are disrupted under light of peak wavelengths longer than 565 nm, and shifts...

.... After New Year, the photoperiod was increased to L:D 13 h:11 h, a treatment that advances the robins’ annual cycle so that they were exhibiting Zugunruhe a few days later, when testing began. A current hypothesis of avian magnetoreception proposes that magnetic compass information is mediated...

... in the magnetic field. In the second experiment, we tested whether the magnetic compass orientation found in the first experiment depends on a light stimulus by testing a group of mole rats in the eight-armed maze under total darkness. No significant difference in directional preference between light and dark...

... their position. The transient nature of the effect is not easily explained on the basis of single-domain magnetite. 08 09 1998 10 11 1998 Copyright © 1998 The Company of Biologists Ltd. 1998 magnetite pulse magnetization bird migration migratory orientation magnetic compass...

... disrupted, we show that bees can use a magnetic direction to discriminate between the patterns. 19 2 1996 ©The Company of Biologists Limited 1996 honeybee visual pattern learning magnetic compass orientation Under some conditions, insects learn visual patterns retinotopically...