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Initial findings on visual acuity thresholds in an African elephant ( Loxodonta africana )
Author(s) -
ShyanNorwalt Melissa R.,
Peterson Jeff,
Milankow King Barbara,
Staggs Timothy E.,
Dale Robert H.I.
Publication year - 2009
Publication title -
zoo biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.5
H-Index - 54
eISSN - 1098-2361
pISSN - 0733-3188
DOI - 10.1002/zoo.20259
Subject(s) - elephas , asian elephant , visual acuity , african elephant , biology , trunk , stimulus (psychology) , optometry , ophthalmology , psychology , zoology , ecology , medicine , cognitive psychology
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.