monkey trivia

I learned today from a tech who works with primates in a research lab that certain monkeys produce grey semen that dries into a solid mass minutes after it is ejaculated. He said that this is an adaptation that improves the odds of a male passing his seed along to a female, who may be mating with several different males on a given day, by blocking the path to the fallopian tubes for subsequent ejaculate ("closing the door," as it were). This tech said he knows this first hand because monkeys enjoy masturbating and he often finds little grey blobs on the floors of their cages.