Visual detection threshold in the echolocating Daubenton’s bat (Myotis daubentonii)

• All bats possess eyes that are of adaptive value. Echolocating bats have retinae dominated by rod photoreceptors and use dim light vision for navigation, and in rare cases for hunting. However, the visual detection threshold of insectivorous echolocating bats remains unknown. Here, we determined this threshold for the vespertilionid bat Myotis daubentonii. We show that for a green luminous target, M. daubentonii has a visual luminance threshold of 3.2(±0.9)×10−4 cd m−2, an intensity corresponding to the luminance of an open cloudless terrestrial habitat on a starlit night. Our results show that echolocating bats have good visual sensitivity, allowing them to see during their active periods. Together with previous results showing that M. daubentonii has poor visual acuity (∼0.6 cycles deg−1), this suggests that echolocating bats do not use vision to hunt but rather to orient themselves.

Ämnesord

NATURVETENSKAP  -- Biologi -- Zoologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Zoology (hsv//eng)

NATURVETENSKAP  -- Biologi -- Etologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Behavioural Sciences Biology (hsv//eng)

Nyckelord

Absolute sensitivity

Bat vision

Behaviour

Nocturnal vision

Psychophysics

Publikations- och innehållstyp

art (ämneskategori)

ref (ämneskategori)