Initial findings on visual acuity thresholds in an African elephant (Loxodonta africana)
Publication Type: |
Journal Article |
Year of Publication: |
2010 |
Authors: |
Melissa R. Shyan-Norwalt, Jeff Peterson, Barbara Milankow King, Timothy E. Staggs, Robert H. I. Dale |
Publication/Journal: |
Zoo Biology |
Publisher: |
A Wiley Company, Inc., Wiley Subscription Services |
Keywords: |
african elephant, eye, vision, visual acuity |
ISBN: |
1098-2361 |
Abstract:
Abstract 10.1002/zoo.20259.abs There are only a few published examinations of elephant visual acuity. All involved Asian elephants (Elephas maximus) and found visual acuity to be between 8′ and 11′ of arc for a stimulus near the tip of the trunk, equivalent to a 0.50 cm gap, at a distance of about 2 m from the eyes. We predicted that African elephants (Loxodonta africana) would have similarly high visual acuity, necessary to facilitate eye-trunk coordination for feeding, drinking and social interactions. When tested on a discrimination task using Landolt-C stimuli, one African elephant cow demonstrated a visual acuity of 48′ of arc. This represents the ability to discriminate a gap as small as 2.75 cm in a stimulus 196 cm from the eye. This single-subject study provides a preliminary estimate of the visual acuity of African elephants. Zoo Biol 29:30–35, 2010. © 2009 Wiley-Liss, Inc.