The Sun Compass

Schmidt-Koenig, Klaus; Ganzhorn, Jörg U.; Ranvaud, Ronald

doi:10.1007/978-3-0348-7208-9_1

Cited by 63 publications

(31 citation statements)

References 24 publications

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“…The ‘map-and-compass’ concept1213 suggests a two-step process: first, an animal detects its current position relative to the goal using a ‘map sense’ and then maintains a chosen direction to a goal using a ‘compass sense’. The nature of a ‘compass sense’ can be based on solar cues1314, stellar cues1516, or the geomagnetic field17, but the nature of a ‘map sense’ used to obtain positional information largely remains a mystery, at least for migratory landbirds.…”

mentioning

confidence: 99%

Experienced migratory songbirds do not display goal-ward orientation after release following a cross-continental displacement: an automated telemetry study

Kishkinev

Heyers

Woodworth

et al. 2016

Sci Rep

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The ability to navigate implies that animals have the capability to compensate for geographical displacement and return to their initial goal or target. Although some species are capable of adjusting their direction after displacement, the environmental cues used to achieve this remain elusive. Two possible cues are geomagnetic parameters (magnetic map hypothesis) or atmospheric odour-forming gradients (olfactory map hypothesis). In this study, we examined both of these hypotheses by surgically deactivating either the magnetic or olfactory sensory systems in experienced white-throated sparrows (Zonotrichia albicollis) captured in southern Ontario, Canada, during spring migration. Treated, sham-treated, and intact birds were then displaced 2,200 km west to Saskatchewan, Canada. Tracking their initial post-displacement migration using an array of automated VHF receiving towers, we found no evidence in any of the groups for compensatory directional response towards their expected breeding grounds. Our results suggest that white-throated sparrows may fall back to a simple constant-vector orientation strategy instead of performing true navigation after they have been geographically displaced to an unfamiliar area during spring migration. Such a basic strategy may be more common than currently thought in experienced migratory birds and its occurrence could be determined by habitat preferences or range size.

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mentioning

confidence: 99%

Experienced migratory songbirds do not display goal-ward orientation after release following a cross-continental displacement: an automated telemetry study

Kishkinev

Heyers

Woodworth

et al. 2016

Sci Rep

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“…Forward extrapolation (9, 18): bees are assumed to measure the rate of azimuthal shift over the last hour of the training period (9.8 deg-hr-1), then to estimate the sun's position in the morning by compensating clockwise at this rate through the night from the end of the previous day's training period (19:20, 2980). 3. Backward extrapolation (9): bees are assumed to measure the net rate of shift over the first hour of the training period (9.7 deg-hr-1) and to compensate counterclockwise at this rate to determine the azimuth at times prior to the start ofthe training period (15:00, 2540) on subsequent days.…”

Section: Resultsmentioning

confidence: 99%

“…A wide variety of animals can use the sun's azimuth as a true compass, compensating for its daily movement relative to terrestrial features (1)(2)(3). Complicating this task is that the azimuth changes at a variable rate over the day, shifting relatively slowly as the sun rises in the morning or sets in the evening and rapidly as the sun crosses the local meridian at midday.…”

mentioning

confidence: 99%

Development of sun compensation by honeybees: how partially experienced bees estimate the sun's course.

Dyer

Dickinson

1994

Proc. Natl. Acad. Sci. U.S.A.

115

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Honeybees and some other insects, in learning the sun's course, behave as if they can estimate the sun's position at times of day when they have never seen it, but there are competing ideas about the computational mechanisms underlying this ability. In an approach to this problem, we provided incubator-reared bees with opportunities to fly and see the sun only during the late afternoon. Then, on a cloudy day, we allowed bees to fly for the first time during the morning and early afternoon, and we observed how they oriented their waggle dances to indicate their direction offlight relative to the sun's position. The clouds denied the bees a direct view of celestial orientation cues and thus forced them to estimate the sun's position on the basis of their experience on previous evenings. During the test days, experience-restricted bees behaved during the entire morning as if they expected the sun to be in an approximately stationary position about 180°from the average solar azimuth that they had experienced on previous evenings; then from about local noon onward they used the evening azimuth. This pattern suggests that honeybees are innately informed of the general pattern of solar movement, such that they can generate an internal representation that incorporates spatial and temporal features of the sun's course that they have never directly seen.A wide variety of animals can use the sun's azimuth as a true compass, compensating for its daily movement relative to terrestrial features (1-3). Complicating this task is that the azimuth changes at a variable rate over the day, shifting relatively slowly as the sun rises in the morning or sets in the evening and rapidly as the sun crosses the local meridian at midday. Furthermore, the daily pattern of change, the ephemeris function, varies with season and with latitude. Animals are generally thought to learn the current local ephemeris function, rather than using the average rate of shift of the azimuth. What little is known about this learning process suggests that animals do not merely memorize a series of time-linked solar positions. Instead, in a wide range of invertebrate (4-12) and vertebrate (13-15) taxa, animals have been shown to estimate solar positions that they have never seen. For example, in a classic series of experiments, Lindauer (4, 5) showed that incubator-reared honeybees (Apis mellifera) that were allowed to see only the western half ofthe sun's course (from noon onward each day) could, when they flew for the first time in the morning, use the sun to search for food in a direction in which they had been trained. Thus, somehow they had correctly learned to expect the sun in the eastern half of the sky in the morning. In this paper we ask what integrative mechanism might underlie this apparent ability ofbees to compute solar positions that till gaps in their experience of the sun's course.Four distinct computational strategies have been proposed to account for the ability of insects to estimate unknown positions of the sun. Three of these assu...

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“…In the models and theories explaining the orientation behaviour of these animals, it is always assumed that in any point of the celestial hemisphere the direction of polarization of skylight is perpendicular to the scattering plane determined by the sun, the observer and the point observed (e.g. Kirschfeld et al 1975;Wehner 1976Wehner , 1983Wehner , 1984Wehner , 1989Wehner , 1994Wehner , 1997van der Glas 1977;Rossel et al 1978;Brines 1980;Able 1982;Phillips and Waldvogel 1982;Rossel and Wehner 1982;Wehner and Rossel 1985;Able and Able 1990;Schmidt-Koenig et al 1991;Hawryshyn 1992;Shashar et al 1998;Freake 1999;Labhart and Meyer 1999). Hence, in the literature dealing with the sky compass orientation of these animals, it is hypothesized that the celestial pattern of the direction of polarization follows the rules of the first-order Rayleigh scattering of sunlight in the atmosphere (Coulson 1988;Dennis 2007;Hannay 2007).…”

Section: How Well Does the Rayleigh Model Describe The Pattern Of Thementioning

confidence: 99%

Polarization of the Sky

Horváth

Barta²,

Hegedüs

2014

Polarized Light and Polarization Vision in Animal Sciences

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International audienceBased on full-sky imaging polarimetric measurements, in this chapter we demonstrate that the celestial distribution of the angle of polarization (or E-vector direction) of skylight is a very robust pattern being qualitatively always the same under all possible sky conditions. Practically the only qualitative difference among clear, partly cloudy, overcast, foggy, smoky and tree-canopied skies occurs in the degree of linear polarization d: The higher the optical thickness of the non-clear atmosphere, the lower the d of skylight. We review here how well the Rayleigh model describes the E-vector pattern of clear and cloudy skies. We deal with the polarization patterns of foggy, partly cloudy, overcast, twilight, smoky and total-solar-eclipsed skies. We describe the possible influences of the changed polarization pattern of smoky and eclipsed skies on insect orientation. We consider the polarization of ‘water-skies’ above Arctic open waters and the polarization characteristics of fogbows. Finally, we deal with the change of skylight polarization due to the transmission through Snell’s window of the flat water surface

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The Sun Compass

Cited by 63 publications

References 24 publications

Experienced migratory songbirds do not display goal-ward orientation after release following a cross-continental displacement: an automated telemetry study

Experienced migratory songbirds do not display goal-ward orientation after release following a cross-continental displacement: an automated telemetry study

Development of sun compensation by honeybees: how partially experienced bees estimate the sun's course.

Polarization of the Sky

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