Initial findings on visual acuity thresholds in an African elephant (Loxodonta africana).
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.
Shyan-Norwalt
Melissa R
MR
Department of Psychology, Butler University, Indianapolis, Indiana, USA. mshyan@earthlink.net
Peterson
Jeff
J
Milankow King
Barbara
B
Staggs
Timothy E
TE
Dale
Robert H I
RH
D000818:Animals; D004606:Elephants / Q000502:physiology*; D005260:Female; D014792:Visual Acuity / Q000502:physiology*