Butterfly shows rare ability of seeing two shades of UV

摘要

FEMALE red postman butterflies see an extra colour in the ultraviolet part of the light spectrum that even the males of their species cannot. While many animal species can see one colour of UV, making out multiple shades in this part of the spectrum is rare. Susan Finkbeiner at California State University, Long Beach, and Adriana Briscoe at the University of California, Irvine, trained 80 Heliconius erato butterlies, an American species, and 120 butterflies from two other species to sip from a feeder placed on a light source that was tuned to a specific UV wavelength.