ARE CHEMICAL CUES AS EFFECTIVE AS PUP CONTACT FOR INDUCING PATERNAL BEHAVIOR IN MEADOW VOLES

We tested what social cues mediate the transition from non-parental to parental behavior in male meadow voles, based on our previous finding s that postpartum interaction with mate and pups was the most effectiv e social experience for making males paternal. Males housed with their mates and pups for a day were more paternal and less aggressive to un related pups than males removed from their mates before parturition. M ales housed with their mates, but with the litter removed, interacted with pups but were initially as likely to be aggressive as males with no exposure to mates and pups. These results suggest that the mate fac ilitates interaction with pups, but exposure to pups accelerates the s ensitization process. Twenty-four hours of exposure to chemical cues f rom the mate and pups (mother and litter in cage with wire mesh floor suspended above male's cage) eliminated male aggression towards pups, but physical contact was necessary to enhance positive interactions wi th pups. Exposure to chemical cues from parturient mates reduced aggre ssion, whereas cues from non-mates were not effective. These results m ay explain our previous findings that females keep sires removed durin g pregnancy out of the nest for about a day after reintroduction (whil e males become sensitized via chemosignals), and continue repelling un familiar males (that would not be sensitized by chemical cues from non -mates).