Spontaneous directional preference in a subterranean rodent, the blind mole-rat, Spalax ehrenbergi

When released in a circular arena, blind mole-rats, Spalax ehrenbergi (kary otype 2n=60), from Israel displayed a significant preference for nesting at 72 degrees and for building food caches at 37 degrees, whereas the positio ns of latrines were not significantly different from a random distribution. The food cache and nest positions were related to each other. There were s ignificant differences in scatter between both sexes in nest and in food ca che directions which may reflect sex-dependent differences in the structure of burrow systems as known from the field. The exhibited preference and mo tivation for nesting appeared not to be affected by the season of the year. We suggest that the spontaneous preference for a certain direction may pro vide an animal with a reference point in a monotonous dark environment depr ived of sensory cues. A possibility that the directional preference in the blind mole-mt may be related to magnetic compass orientation, as known in t he Zambian common mole-rat (Cryptomys anselli), also a subterranean rodent. is discussed.