Are harbour seals (Phoca vitulina) able to perceive and use polarised light?
Författare
Summary, in English
Harbour seals are active at night and during the day and see well in both air and water. Polarised light, which is a well-known visual cue for orientation, navigation and foraging, is richly available in harbour seal habitats, both above and below the water surface. We hypothesised that an ability to detect and use polarised light could be valuable for seals, and thus tested if they are able to see this property of light. We performed two behavioural experiments, one involving object discrimination and the other involving object detection. These objects were presented to the seals as two-dimensional stimuli on a specially modified liquid crystal display that generated objects whose contrast was purely defined in terms of polarisation (i.e. objects lacked luminance contrast). In both experiments, the seals' performance did not deviate significantly from chance. In contrast, the seals showed a high baseline performance when presented with objects on a non-modified display (whose contrast was purely defined in terms of luminance). We conclude that harbour seals are unable to use polarised light in our experimental context. It remains for future work to elucidate if they are polarisation insensitive per se.
Avdelning/ar
Publiceringsår
2013
Språk
Engelska
Sidor
509-519
Publikation/Tidskrift/Serie
Journal of Comparative Physiology A
Volym
199
Issue
6
Dokumenttyp
Artikel i tidskrift
Förlag
Springer
Ämne
- Zoology
Nyckelord
- Harbour seal
- Phoca vitulina
- Polarisation
- Object detection
- Liquid
- crystal display monitor
Status
Published
Forskningsgrupp
- Lund Vision Group
ISBN/ISSN/Övrigt
- ISSN: 1432-1351