The Safe Aircraft Competition, The Sun Compass, and more

1930 ◽  
Vol 142 (3) ◽  
pp. 232-234
Author(s):  
Alexander Klemin
Keyword(s):  
The Sun ◽  
Sun Compass

Orientation and dispersal of hatchling Blanding’s turtles (Emydoidea blandingii) from experimental nests

2009 ◽  
Vol 87 (9) ◽  
pp. 755-766 ◽  
Author(s):  
M. J. Pappas ◽  
J. D. Congdon ◽  
B. J. Brecke ◽  
J. D. Capps
Keyword(s):  
Forest Succession ◽  
Environmental Cues ◽  
The Sun ◽  
Dispersal Patterns ◽  
Sun Compass ◽  
Emydoidea Blandingii ◽  
Late Afternoon ◽  
Nest Sites ◽  
Pine Trees ◽  
Riparian Habitats

We determined initial dispersal directions of 1052 naïve and 278 experienced hatchling Blanding’s turtles (Emydoidea blandingii (Holbrook, 1838)) in experimental arenas in a variety of settings. Dispersal of naïve hatchlings was nonrandom in 7 of 10 sites. All nonrandom dispersal patterns suggested hatchlings primarily used vision to orient toward dark far horizons, particularly those associated with riparian habitats. We found no evidence that hatchlings use positive geotaxis, olfaction, humidity gradients, or scent trailing of other individuals during dispersal. Despite the lack of relationships between the changing position of the sun and relationships between nest sites and wetlands, patterns of dispersal were different for hatchlings released in the morning and late afternoon at two sites. Comparisons of the dispersal of naïve and translocated experienced hatchlings (those with previous exposure to environmental cues) suggest that hatchlings develop a sun compass within 2 days of emergence from nests. Based on all nonrandom dispersals of hatchlings at arenas, the estimated maximum perception distance of hatchlings was 325 m. In some situations, forest succession, agriculture activities, and introduction of pine trees may increase risks faced by hatchlings dispersing from nests by reducing their ability to find wetlands.

scholarly journals DINAMIKA PENENTUAN ARAH KIBLAT

2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Dwi Putra Jaya
Keyword(s):  
The Sun ◽  
Sun Compass ◽  
Early Stages ◽  
The Temple ◽  
The Way

Abstract: To know the direction of Qiblah is already a lot of tools. Can be through measurements, can also use a prayer rug that has a compass Qiblah direction that is widely used in mosques. However, in order to attain the virtue of charity, it is necessary to make sure that the direction approached in the direction precisely facing the Temple. The way of determining the direction of the Qiblah for mosques has evolved in accordance with the development of knowledge held by Islamic societies, in the early stages using a very simple way, then progressed by using tools to measure it, among them Trigonometry, the shadow of the sun, compass magnet, transparent compass, compass Qibla, protractor, Rubu ‘mujayyab, string or thread, stick istiwa’ and waterpas, lot, elbow.

Dominance of Celestial Cues over Landmarks Disproves Map-Like Orientation in Honey Bees

1990 ◽  
Vol 45 (6) ◽  
pp. 723-726 ◽  
Author(s):  
Randolf Menzel ◽  
Lars Chittka ◽  
Stefan Eichmüller ◽  
Karl Geiger ◽  
Dagmar Peitsch ◽  
...  
Keyword(s):  
Honey Bees ◽  
Recent Model ◽  
The Sun ◽  
Sun Compass ◽  
Landmark Orientation ◽  
Mental Map ◽  
Mental Operations

Abstract A recent model of landmark orientation by the bee assumes that the memory of the landmarks is arranged in a kind of a mental map. Our experiments disprove this assumption and show that the sun compass dominates the orientation without any indication of mental operations within a map-like representation of landmarks or of compass vectors and distances.

The Initial Orientation of Homing Pigeons at the Magnetic Equator: Compass Mechanisms and the Effect of Applied Magnets

1991 ◽  
Vol 161 (1) ◽  
pp. 299-314
Author(s):  
RONALD RANVAUD ◽  
KLAUS SCHMIDT-KOENIG ◽  
JÖRG U. GANZHORN ◽  
JAKOB KIEPENHEUER ◽  
ODIVAL C. GASPAROTTO ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Migratory Birds ◽  
Sensory System ◽  
Magnetic Equator ◽  
The Sun ◽  
Sun Compass ◽  
Homing Pigeons ◽  
Directional Preference ◽  
Compass Mechanisms ◽  
Inclination Compass

Homing pigeons are thought to use the earth's magnetic field for direction finding. Though the sensory system and the characteristics of the magnetic field used are unknown, it can be hypothesized that pigeons have an inclination compass, as do some migratory birds. When released at the magnetic equator, this inclination compass ought to be suspended. In addition, releasing pigeons when the sun is at or very close to the zenith renders the sun compass inoperational. However, released under these conditions, homing pigeons are not disorientated. Though they vanish on average in a different direction from pigeons released when the sun compass is available, they still show a directional preference close to magnetic north. This directional preference could be disrupted in some years by the application of magnets to the pigeons' back. In other years this treatment as well as another magnetic treatment did not produce any difference between experimental pigeons and controls. These results confirm once more that, if magnetic effects exist, they are of a rather discrete nature.

scholarly journals Matched-filter coding of sky polarization results in an internal sun compass in the brain of the desert locust

2020 ◽  
Vol 117 (41) ◽  
pp. 25810-25817
Author(s):  
Frederick Zittrell ◽  
Keram Pfeiffer ◽  
Uwe Homberg
Keyword(s):  
Spatial Orientation ◽  
Matched Filter ◽  
Polarized Light ◽  
Central Complex ◽  
Insect Brain ◽  
The Sun ◽  
Polarization Pattern ◽  
Sun Compass ◽  
Small Spot ◽  
Polarization Compass

Many animals use celestial cues for spatial orientation. These include the sun and, in insects, the polarization pattern of the sky, which depends on the position of the sun. The central complex in the insect brain plays a key role in spatial orientation. In desert locusts, the angle of polarized light in the zenith above the animal and the direction of a simulated sun are represented in a compass-like fashion in the central complex, but how both compasses fit together for a unified representation of external space remained unclear. To address this question, we analyzed the sensitivity of intracellularly recorded central-complex neurons to the angle of polarized light presented from up to 33 positions in the animal’s dorsal visual field and injected Neurobiotin tracer for cell identification. Neurons were polarization sensitive in large parts of the virtual sky that in some cells extended to the horizon in all directions. Neurons, moreover, were tuned to spatial patterns of polarization angles that matched the sky polarization pattern of particular sun positions. The horizontal components of these calculated solar positions were topographically encoded in the protocerebral bridge of the central complex covering 360° of space. This whole-sky polarization compass does not support the earlier reported polarization compass based on stimulation from a small spot above the animal but coincides well with the previously demonstrated direct sun compass based on unpolarized light stimulation. Therefore, direct sunlight and whole-sky polarization complement each other for robust head direction coding in the locust central complex.

scholarly journals Is There Visual Lateralisation of the Sun Compass in Homing Pigeons?

Symmetry ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 740 ◽  
Author(s):  
Charlotte Griffiths ◽  
Richard Holland ◽  
Anna Gagliardo
Keyword(s):  
Visual System ◽  
Right Hemisphere ◽  
Natural Setting ◽  
The Sun ◽  
Sun Compass ◽  
Homing Pigeons ◽  
Significant Difference ◽  
Conflict Condition ◽  
The Right ◽  
Cue Conflict

Functional lateralisation in the avian visual system can be easily studied by testing monocularly occluded birds. The sun compass is a critical source of navigational information in birds, but studies of visual asymmetry have focussed on cues in a laboratory rather than a natural setting. We investigate functional lateralisation of sun compass use in the visual system of homing pigeons trained to locate food in an outdoor octagonal arena, with a coloured beacon in each sector and a view of the sun. The arena was rotated to introduce a cue conflict, and the experimental groups, a binocular treatment and two monocular treatments, were tested for their directional choice. We found no significant difference in test orientation between the treatments, with all groups showing evidence of both sun compass and beacon use, suggesting no complete functional lateralisation of sun compass use within the visual system. However, reduced directional consistency of binocular vs. monocular birds may reveal a conflict between the two hemispheres in a cue conflict condition. Birds using the right hemisphere were more likely to choose the intermediate sector between the training sector and the shifted training beacon, suggesting a possible asymmetry in favour of the left eye/right hemisphere (LE/RH) when integrating different cues.

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