Sheep and goat mothers, like human ones, form exclusive bonds with their babies. Thus, says Keith Kendrick, a neuroscientist at the Babraham Institute in Cambridge, England, the mothers can have "an extraordinary influence on their offspring." To determine the extent of that influence, Kendrick had goats serve as foster mothers to 21 newborn lambs and had sheep mother 18 baby goats. When the adopted babies grew up, he found that the male sheep and goats preferred to socialize and have sex with females of their foster mothers' species, even after living exclusively with their own kind for three years. Adopted females, however, were more flexible and could readapt to their own species.
Sheep and goats can recognize faces, says Kendrick, and he suggests that the males use their mothers' faces as models when selecting mates. As for the females, he speculates that since they tend to form a wider variety of social bonds during their lives--with mates, other females, and their own progeny--than males do, they may be more flexible in social relationships and not depend so much on early experiences. "We're all aware of the claim that men end up marrying women who look like their mothers," he says. Of his own mother, Kendrick says, "There is a close resemblance between her and my wife in terms of face shape, but not hair or eye color."