Polarisation vision: overcoming challenges of working with a property of light we barely see

Abstract

In recent years, the study of polarisation vision in animals has seen numerous breakthroughs, not just in terms of what is known about the function of this sensory ability, but also in the experimental methods by which polarisation can be controlled, presented and measured. Once thought to be limited to only a few animal species, polarisation sensitivity is now known to be widespread across many taxonomic groups, and advances in experimental techniques are, in part, responsible for these discoveries. Nevertheless, its study remains challenging, perhaps because of our own poor sensitivity to the polarisation of light, but equally as a result of the slow spread of new practices and methodological innovations within the field. In this review, we introduce the most important steps in designing and calibrating polarised stimuli, within the broader context of areas of current research and the applications of new techniques to key questions. Our aim is to provide a constructive guide to help researchers, particularly those with no background in the physics of polarisation, to design robust experiments that are free from confounding factors.

Heading choices of flyingDrosophilaunder changing angles of polarized light

“…Oriented flights of suspended monarch butterflies under a polarized stimulus have been demonstrated, yet its ethological significance remains somewhat controversial, due to conflicting reports [12][13][14] . Probably the most valuable recent progress comes from the fly Drosophila melanogaster: spontaneous responses of flying Drosophila to linearly polarized light using virtual flight arenas have been demonstrated, both under the natural sky, as well as using an artificial stimulus generated in the laboratory using commercially available polarization filters 15 , [16][17][18] . Most importantly, flies were shown to choose arbitrary angular headings with respect to the orientation of the e-vector of the polarized stimulus and showed the tendency to maintain this navigational decision over several minutes, even when the stimulus presentation was perturbed for several minutes 18 .…”

Transparency reduces predator detection in mimetic clearwing butterflies

“…© Céline Houssin Differences in colour perception between great tits and humans include the presence of a fourth single cone type receptor (instead of three cones in humans) that extend the great tits' sensitivity into the UV light spectrum (Hart, 2001) and oil droplets that refine colour discrimination in birds (Vorobyev, 2003). However, neither humans nor birds are able to detect linear polarization, which excludes the use of polarization cues to detect and discriminate between butterfly species (Foster et al, 2018;Greenwood, Smith, Church, & Partridge, 2003;Melgar, Lind, & Muheim, 2015;Montgomery & Heinemann, 1952). Moreover, humans have been found to be good predictors of insect prey survival in the wild (Penney, Hassall, Skevington, Abbott, & Sherratt, 2012).…”

Linear Polarization Characteristics Within the Rosh HaNikra Mid-Littoral Cave, Israel

“…A SMA 905 connector and a single-strand long optical fiber probe, as specified by Foster et al (2017), were used. The numerical aperture of the fiber optic-based probe is 0.22, which corresponds to an angular field of view of ∼25.4…”

“…It has been shown that photosynthetic organisms can adjust their own orientation and situation or their chloroplast orientation in order to optimize the light harvesting and photosynthetic efficiency of their cells (Foster and Smyth, 1980;Dubinsky, 1992;Wada et al, 1993;Takagi, 2003;Iluz and Dubinsky, 2015). Along with the intensity and spectral distribution of light, the polarization of light has also been found to affect cell and chloroplast orientation (Etzold, 1965;Zurzycki, 1967;Haupt, 1982;Hader, 1987;Kagawa and Wada, 1995). Studies have shown that chloroplasts, thylakoids, and phycobilisomes may have dichroitic polarized absorption properties, due to pigment orientation (Goedheer, 1955;Breton et al, 1973;Haworth et al, 1982;Frackowiak et al, 1985Frackowiak et al, , 1986Gagliano et al, 1985).…”