Tuesday, August 18, 2009
Call them ugly or cute, you must see our baby naked mole-rats. Looks aside, we are very excited to have developed husbandry protocols that helped get them through their crucial first week of life.
Eighteen months ago, the prospect of rearing mole-rat pups was a distant hope. Our colony was in serious trouble. We had lost half a dozen workers in as many months. Inexplicably, each animal’s necropsy (animal autopsy) showed unique causes of death –there was no single cause.
Making any major changes to these animals’ care is risky. As eusocial animals, mole-rats depend on scent cues to recognize members of their own colony. Any antibiotic treatment must be carefully developed to avoid killing their life-giving, symbiotic bacteria.
Two things caused me to consider trying antibiotics and husbandry changes. One was negative: the losses in the colony. Despite my fears about treatment, the risk of doing nothing was greater. The positive side was our new veterinary service, Avian and Exotic Animal Hospital . Dr’s Maas and Ferguson were committed to develop a protocol to bring the colony back into perfect health. They carefully examined the animals, testing their blood, stools, urine and nostrils for signs of infection. In due course, they developed treatment designed with mole-rats’ delicate digestive and behavioral needs in mind.
After two intense weeks of daily injections for each of our 23 colony members, bleaching their home and replacing all their contact surfaces, we saw glimmers of hope. Animals started gaining weight and the mysterious deaths ceased.
But the first pregnancy after these treatments ended badly. And over time, pups were born but the colony appeared unwilling or unable to rear them.
Interfering in the behavior of highly social animals often does more harm than good, but our colony had come to a reproductive standstill – adults were doing well, but the babies could not survive. Perhaps the colony, lacking experience with successfully rearing pups, needed some adjustments, at least to successfully bring up one litter.
Three days before her due date, the pregnant queen and two helpers were settled in chambers separated from the rest of the colony. To keep all the workers familiar with their queen, we switched one worker every morning and one each night with a new mole-rat from the colony.
When the queen gave birth, the helpers appeared calm but interested in the babies. By the next day we saw encouraging signs – a tiny white region in each pup’s middle indicated milk had made its way into their bellies.
On the tenth day (August 17), the pups were old enough to right themselves and move independently. Soon they will show interest in solid food. Next we can begin reintegrating the queen and her helpers into the colony.
The first year of a mole-rat’s life is one of challenge but with the most difficult ten days behind them, these pups are off to a good start!
Congratulations if you read this far! The first person to post a comment or question below wins a “behind the scenes” chance to help us care for the mole-rats, and if you wish, you may help choose color markings to identify the new babies.
-Sarah Moore, Life Sciences program manager