More Naked Mole-rat Pups May Be on the Way

There seems to be a favorite in the naked mole-rat colony. One of the adult females has attacked every other adult female in the colony — except the queen — ultimately killing them. The only two remaining females in the colony are the queen and this “favorite” female. Keepers are unsure why this particular female has been so aggressive toward the other mole-rats.

It is not uncommon for naked mole-rats to have bloody skirmishes or aggressive encounters, called “mole-rat wars.” They usually break out if an intruder is detected in the colony, if another female is challenging the queen or if a colony is in the process of establishing a new queen after the previous queen dies.

Most of the fights and attacks happened before the queen gave birth to her first litter of pups, but one final attack happened in February. Since then, the colony has been calm. If any of the pups born in December are female, they may not attract the aggression of the “favorite,” because they are the offspring of the queen. The other adult females who have died after attacks were not the queen's direct offspring.

The colony's four pups are healthy and thriving, quickly growing to adult size. They will have their first veterinary exam and receive their identification chips when they are about six months old — and there are likely more pups on the way! The queen is capable of becoming pregnant within two weeks of giving birth, so keepers are caring for the colony with the expectation that the queen is pregnant. There could be new pups born as early as mid-March.

It is likely that queen will have more pups in her next litter than in her first litter. Each time a queen gives birth, her spine becomes a tiny bit more elongated, which allows her to carry more pups. Naked mole-rats live in tunnels, so if a queen were to get wider while pregnant she would likely get stuck. Evolution came up with the elegant solution of allowing her spine to incrementally elongate, allowing her to carry more pups without becoming trapped in the tunnels that her own colony excavated.

Keep up with the Zoo’s naked mole-rat colony on the live webcam.