This story has been updated to reflect the fact that the research was conducted exclusively on male mongooses, so there were no mama mongooses involved.
Parents often display incredible feats of altruism, but even they have their limits. All of that give-give-give required to raise pups does take a toll--sometimes to the point that they are averse to ever going that caretaker distance again. According to new research, banded mongoose papas that give 110 percent in rearing their pups the first time around are less likely to deliver that level of care to future litters.
Scientists studying banded mongooses that live in Uganda found that stress hormones are the culprits behind the shift in fatherly devotion. The more a father mongoose invests in caring for his pups, the higher his levels of stress, as measured by hormones called glucocorticoids that turn up in the mongooses' feces.
Mongoose participate in group care, so males will often take care of not only their own pups but those of others as well. When stress was high, however, the males were more likely to neglect others' pups and to invest less heavily in their own. Males that had previously become very stressed out when raising pups showed increase levels of stress on the second time around. Their bodies continued to produce stress hormones for some time even after they stopped caring for the new babies.
Just as with humans, an animal's past experience can affect how it behaves in the futures, the authors point out. In the case of the banded mongoose fathers, now they know one of the physiological mechanisms behind that carry-over effect.