Ejaculate disruption in two species of voles (Microtus): on the PEI matching law.
We permitted male prairie and montane voles (Microtus ochrogaster and M. montanus) five thrusts, without ejaculation, with a female at variable times after a 1st male ejaculated. In both prairie and montane voles, there were fewer sperm, in relation to control conditions, in the female's tract 1 hr after ejaculation if the female received thrusts immediately or 15 min after the ejaculate. There was no such effect after a 50-min delay. There was no significant decrease in litter production in prairie voles caused by thrusts delivered either immediately or after a 15-min delay. Sperm transport in these species is susceptible to disruption for a longer period than in deer mice or rats. The proposal that the postejaculatory interval protects a male from disrupting its own sperm transport (the PEI matching law) appears not to hold for these species.
Dewsbury
D A
DA
Department of Psychology, University of Florida, Gainesville 32611-2065.
Bauer
S M
SM
Pierce
J D
JD
Shapiro
L E
LE
Taylor
S A
SA
D000818:Animals; D003411:Arvicolinae / Q000502:physiology*; D003307:Copulation / Q000502:physiology*; D004542:Ejaculation / Q000502:physiology*; D005260:Female; D008297:Male; D013076:Sperm Count; D013083:Sperm Transport / Q000502:physiology*