Light perception in 'blind' subterranean Zambian mole-rats.

In: Animal Behaviour, Jg. 72 (2006) ; Nr. 5, S. 1021-1024
ISSN: 0003-3472
Zeitschriftenaufsatz / Fach: Biologie
Because of their constantly dark habitat and microphthalmia, subterranean African mole-rats have hitherto
been considered as blind. Recent morphological findings, however, revealed a qualitatively rather
well-developed, although quantitatively reduced, visual system and questioned the prevailing idea of
blindness. We investigated the reactions of Zambian mole-rats of the bathyergid genus Fukomys (formerly
Cryptomys) to white light during nest building. Using a two-armed test chamber with a choice between
strong halogen light and darkness, we found that mole-rat pairs avoided the illuminated chamber and
nested significantly more often in the dark box. With the same protocol in an eight-armed maze, we confirmed
this heliophobic (or scotophilic) behaviour under natural daylight conditions. Zambian mole-rats
can thus perceive natural light intensities and use photic information, for example to decide where to nest.