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A small falcon, the American kestrel (Falco sparverius), looking at a Snellen chart. A comparative study of human and falcon visual acuity shows that the kestrel can resolve the upper line from a distance of 100 yards. See page 263. [Barry Stein, Nashville, Tennessee]


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Science. ISSN 0036-8075 (print), 1095-9203 (online)