Effects of consanguinity, exposure to pregnant females, and stimulation from young on male gerbils' responses to pups

In three experiments investigating variables affecting responses of male Mo ngolian gerbils to conspecific young, we compared the behavior directed tow ards pups of natural fathers, virgin foster fathers, and sexually experienc ed foster fathers (Experiment 1); males either previously exposed or not ex posed to pregnant females (Experiment 2); and males provided or not provide d with extra opportunities to huddle over pups (Experiment 3). We found no difference in responses to pups among natural fathers, virgin foster father s, and foster fathers that had fathered litters. On the other hand, both a week of exposure to a pregnant female and opportunity to huddle over pups f or an extra 15 min/day had significant effects on males' subsequent respons es to conspecific young. We speculate on the reasons why a male's response to pups might be affected by his exposure to a pregnant female and stimuli from pups, but not by the probability that the pups were his own offspring. (C) 2001 John Wiley & Sons, Inc.