REPRODUCTIVE STATUS INFLUENCES ODOR PREFERENCES OF THE MEADOW VOLE, MICROTUS-PENNSYLVANICUS, IN WINTER DAY LENGTHS

Sporadic winter breeding is a common occurrence in populations of arvi coline rodents. To elaborate the olfactory basis of winter breeding, o dor preferences of meadow voles that did or did not develop their repr oductive systems in short day lengths were compared. Voles that did no t respond to short days with reproductive inhibition were reproductive ly mature and are termed nonresponders, while voles that did respond t o short days with reproductive inhibition were reproductively immature and are termed responders. Nonresponder females preferred odors of no nresponder males over those of nonresponder females and nonresponder f emale over responder female odors. Nonresponder males preferred nonres ponder over responder female odors. The mutual attraction between male - female and female - female nonresponders may facilitate winter bree ding and female-female dyad formation for communal rearing of young, r espectively. Responder females preferred odors of female responders ov er those of male responders and responder over nonresponder male odors . Olfactory preferences of nonresponder short-day voles were not equiv alent to those of reproductively competent long-day animals. Differenc es in odor communication between responder and nonresponder voles are attributable only in part to differences in gonadal hormone secretion.