Calibration of the sun compass by sunset polarized light patterns in a migratory bird

1992 ◽  
Vol 31 (3) ◽  
Author(s):  
JohnB. Phillips ◽  
FrankR. Moore
Keyword(s):  
Polarized Light ◽  
Migratory Bird ◽  
The Sun ◽  
Sun Compass

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 Ontogeny of the star compass in birds: pied flycatchers (Ficedula hypoleuca) can establish the star compass in spring

2021 ◽  
Vol 224 (3) ◽  
pp. jeb237875
Author(s):  
Anna Zolotareva ◽  
Gleb Utvenko ◽  
Nadezhda Romanova ◽  
Alexander Pakhomov ◽  
Nikita Chernetsov
Keyword(s):  
Magnetic Field ◽  
Small Sample Size ◽  
Polarized Light ◽  
Ficedula Hypoleuca ◽  
Small Sample ◽  
Autumn Migration ◽  
The Sun ◽  
Vertical Magnetic Field ◽  
Sun Compass ◽  
Star Compass

ABSTRACTThe star compass of birds, like the sun compass, is not innate. To possess either of them, birds have to observe the rotating sky and determine its centre of rotation (in the case of the star compass) or the sun's movement (for the sun compass). Young birds are believed to learn how to use the star compass before their first migration, even though the evidence of this is lacking. Here, we tested whether hand-raised Pied flycatchers (Ficedula hypoleuca) that had not established the star compass prior to their first autumn migration can gain it later in their ontogeny, in spring. We also attempted to examine whether the observation of diurnal celestial cues (the sun and polarized light) prior to autumn migration would affect the process of star compass learning in spring. When tested in the vertical magnetic field under the natural starry sky, the group of birds that observed the stars in spring as the first celestial cues were able to choose the migratory direction. In contrast, the birds that had never seen the stars were not able to use the nightly celestial cues in the vertical magnetic field. However, birds that had seen the daytime celestial cues till autumn and the stars at spring were disoriented, although this might be due to the small sample size. Our data suggest the possibility that the star compass may be learned in spring and emphasize the necessity for further research into the interaction of celestial compasses.

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

Advancing an Ecosystem Approach in the Gulf of Maine

2012 ◽  
Keyword(s):  
New England ◽  
Gulf Of Maine ◽  
Environmental Gradients ◽  
Polarized Light ◽  
Ecosystem Approach ◽  
Water Bloom ◽  
Sun Compass ◽  
Fine Sediments ◽  
Wide Range ◽  
Crangon Septemspinosa

<i>Abstract</i> .—Because of partial recirculation and steep bottom slopes, the Gulf of Maine (GoM) contains steep environmental gradients in both space and time. I focus, in particular, on optical properties associated with both resources and risks. The GoM estuary-shelf systems differ from those whose fine sediments are trapped behind barrier bars; in the GoM, nepheloid layers prevail over a wide range of depths, and onshore-offshore turbidity gradients at a given water depth are also steep. Turbidity reduces predation risk. Three crustacean species that are major fish forages respond to the strong environmental gradients in resources and risks by migrating seasonally both horizontally and vertically. Northern shrimp (also known as pink shrimp) <i>Pandalus borealis</i> , sevenspine bay shrimp <i>Crangon septemspinosa</i> , and the most common mysid shrimp in the GoM, <i>Neomysis americana</i> , share both stalked eyes that appear capable of detecting polarized light and statocysts. This pair of features likely confers sun-compass navigational ability, facilitating use of multiple habitats. All three species converge on a shallow-water bloom at depths <100 m of the western GoM shelf in December–March, well before the basin-wide, climatological spring bloom in April. In addition to reaching abundant food resources, I propose that they are also using optical protection, quantified as the integral of the beam attenuation coefficient from the surface to the depth that they occupy during daylight. Spring immigration into, and fall emigration from, estuaries appear to be common in GoM sevenspine bay shrimp and <i>N. americana</i> , out of phase with their populations south of New England and with turbidity differences a likely cause. Migration studies that include measurements of turbidity are needed, however, to test the strength of the effect of optical protection on habitat use by all three species. Simultaneous sampling of estuaries and the adjacent shelf, together with trace-element tracer studies, would be very useful to resolve timing and extent of mass migrations, which likely are sensitive to turbidity change resulting from climate change. These migrations present special challenges to ecosystem-based management by using so many different habitats.

scholarly journals Problems of Menotactic Orientation According to the Polarized Light of the Sky

1975 ◽  
Vol 30 (1-2) ◽  
pp. 88-90 ◽  
Author(s):  
Kuno Kirschfeld ◽  
M. Lindauer ◽  
H. Martin
Keyword(s):  
Infinite Number ◽  
Polarized Light ◽  
The Sun ◽  
Number Of Solutions ◽  
Special Cases ◽  
Linearly Polarized ◽  
Vector Direction

Abstract It is shown that the knowledge of the E-vector direction of the linearly polarized light at any point of the sky alone is insufficient for the determination of the position of the sun. If the E-vector direction of a second point is not known the knowledge of at least one other parameter is necessary. This parameter might be the height of the sun over the horizon. With the knowledge of the height the infinite number of solutions for the sun’s position becomes reduced to two, or in special cases to one. These cases are derived.

CHANGES IN MOSQUITO FLIGHT ASSOCIATED WITH NATURAL CHANGES IN POLARIZED LIGHT

1974 ◽  
Vol 106 (9) ◽  
pp. 941-948 ◽  
Author(s):  
W. G. Wellington
Keyword(s):  
Polarized Light ◽  
The Sun ◽  
Diurnal Activity ◽  
Oviposition Sites

AbstractDiurnal activity of Aedes and Culex spp. was observed near Banff, Alta., and Hope, B.C., when naturally polarized light was present, reduced, or absent in relatively open habitats. Resting mosquitoes attacked as soon as they were approached closely, whether or not polarized light was present. In contrast, mosquitoes made long, roving flights only when there was polarized light overhead. Roving flight stopped whenever zenith polarization was disrupted by passing clouds or by the unpolarized glare surrounding the sun. As overhead polarization is most intense near sunrise and sunset, it could be employed then by mosquitoes travelling to and from feeding or oviposition sites.

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.

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