Copulatory plugs

Devine, M. C. (1977). Copulatory plugs, restricted mating opportunities and reproductive competition among male garter snakes. Nature 167,345-346. 

Female fecundity index (also, called the conception or pregnancy index) Male mating index No. females inseminated x 100 No. animals paired No. confirmed pregnant x 100 No. with copulatory plug or sperm No. males with pregnant females x 100 No. males... 

Live litter size No. live offspring x 100 No. females with copulatory plug or sperm... 

Breeding and Early Rearing. Animals were mated daily, starting at the beginning of the dark phase, and were checked for the presence of copulatory plugs 7 h later. The day on... 

Crews 1977). In addition, a pheromone associated with the copulatory plug in the plains garter snake (Thamnophis radix) renders captive males sexually refractory for periods of 24-72 h after exposure (Ross Crews 1978). Thus, there appear to be pheromones in the copulatory plug that not only render mated females temporarily unattractive, but also cause sexually active males to become sexually quiescent, ceasing courtship behavior after exposure to this pheromone. Similar studies in the Swedish viper (Vipera berus) did not yield any behaviors similar to those exhibited by garter snakes (Nilson Andren 1982). 

Male garter snakes do not pursue already mated females. These females carry a gelatinous mating plug in their cloaca for about 2 days. Copulatory fluids around her cloaca contain a copulatory pheromone that inhihits males advances. Males detect this copulatory pheromone on a female s trail hy tongue flicking from a distance (O Donnell etat. 2004). 

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