Light-dependent orientation responses in animals can be explained by a model of compass cue integration

Abstract

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The skylight gradient of luminance helps sandhoppers in sun and moon identification

“…Finally, our results do not exclude the perception and use by sandhoppers of other celestial factors, e.g. the sky colour gradient, as demonstrated in ants and bees (Rossel and Wehner, 1986;Wehner, 1997) (see also Jensen, 2010), or the use of the skylight…”

Magnetoreception in eusocial insects: an update

“…If the size particle is lower than the critical SD size, it becomes unstable owing to thermal fluctuations and is called superparamagnetic. The blocking or critical magnetite volume depends on the grain elongation, magnetic interactions among individual grains or chains and relaxation times (Muxworthy & Williams 2006, 2009. The different magnetic stabilities suggest that SD nanoparticles are involved with the magnetic compass and SPM nanoparticles in the magnetic map mechanism ( Johnsen & Lohmann 2005).…”

“…In honeybees, a similar range of wavelengths was observed to affect waggle dances (Leucht 1984). An alternative model was recently proposed to explain the light-dependent mechanism based on an integration process of a light-independent magnetic compass mechanism and a vision-based skylight colour gradient compass that misperceives compass cues in monochromatic light (Jensen 2009). The model suggests the existence of a single magnetic sense that can explain the light-dependent effects in birds, probably based on magnetic particles.…”

Spontaneous magnetic orientation in larval Drosophila shares properties with learned magnetic compass responses in adult flies and mice.

“…However, the possibility that light-dependent effects on compass orientation could result from an interaction between a non-light-dependent (e.g. magnetite-based) magnetic compass and non-magnetic, photoreceptor-based input cannot be excluded (Phillips et al, 2002;Winklhofer and Kirschvink, 2010;Jensen, 2010).…”

“…Jensen proposed that the properties of the light-dependent magnetic compass in birds and possibly other organisms can be explained by an interaction between a non-lightdependent magnetic compass (presumably magnetite based) and a vision-based celestial compass (e.g. a spectral gradient or polarized light compass) (Jensen, 2010). It is noteworthy that Jensen's model suggests that changes in the wavelength and intensity of light could alter the directional response of a hybrid magnetite-based magnetic and light-dependent polarized light (or spectral gradient) compass in a manner similar to that shown in amphibians (Phillips and Borland, 1992).…”