Stanford biologists have recently discovered new reproductive patterns among harvester ant colonies, identifying for the first time parental lineages within wild ant populations and noting longer-than-expected longevity in reproduction among queen ants.

“Most animals produce offspring for awhile, and then they enter a life stage where they don’t,” said Deborah Gordon M.S. ’77, a professor of biology and leader of the project, to the Stanford News Service. “These queen ants are mating once, storing that sperm in a specific sac, keeping it alive and using it to fertilize eggs for another 25 years.”

Gordon has been studying the same colony of harvester ants for the past 28 years in an effort to better understand the species.

For this specific project, her group took DNA samples of each colony to determine which colonies were genetically related. In conjunction with observational analysis, Gordon was able to identify the original queen ant and the order in which her daughter queens established new colonies. The researchers also discovered that only 25 percent of these colonies were able to reproduce at all, indicative that many daughter queens are unsuccessful reproducers.

Their study was published on Jan. 31 in the Journal of Animal Ecology.