Abstract
Scotopic vision in horses (Equus caballus) was investigated using behavioral measurements for the first time. Four horses were tested for the ability to make simple visual discriminations of geometric figures (circles and triangles) under various brightness levels within an enclosed building. Measurements of brightness ranging from 10.37 to 24.12 magnitudes per square arcsecond (mag/arcsec(2); in candelas per square meter-7.70 to 2.43E-05cd/m(2)) were taken using a Sky Quality Meter. These values approximated outdoor conditions ranging from twilight in open country to a dark moonless night in dense forest. The horses were able to solve the discrimination problems in all brightness settings up to 23.77mag/arcsec(2) (3.35E-05cd/m(2)). Moreover, they easily navigated their way around obstacles located within the testing area in extremely dim light (>23.50mag/arcsec(2); 4.30E-05cd/m(2)), which were in conditions too dark for the human experimenters to see. These findings support physiological data that reveal a rod-dominated visual system as well as observations of equine activity at night.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
