Is there any mammal species in which the males breastfeed the young?

Dear Cecil:

Is there any mammalian species where the males breastfeed the young? The reason I ask is that the external mammary features of males of the homo sapiens might be a vestige from a time when men actively participated in childrearing. Needless to say, if men once had milk-producing capability this would have far-reaching socio-sexuo-political ramifications, to say nothing of the gossip value.

Cecil replies:

Sorry to put the kibosh on this idea, Gene, which exhibits the sort of deranged inspiration Cecil loves, but as far as anybody can tell, there is not now and never has been a mammalian species in which the males suckle their young. You bring up an interesting subject, though, and one that confirms one of my pet epistemological theories, namely, that for any conceivable question, no matter how bizarre, there is some twisted genius somewhere who has devoted his life to researching the answer. Just so with male lactation. The genius in this case is one Martin Daly, a psychology professor at McMaster University in Canada. In 1977 he wrote a monograph entitled “Why Don’t Male Mammals Lactate?” which I commend to all serious students of the subject.

Daly notes that there is nothing about male physiology that “appears to present an insurmountable barrier to the evolution of male lactation.” In fact, there are a couple cases on record in which elderly men treated with estrogen for prostate cancer were induced to lactate. The reason lactation hasn’t evolved naturally, Daly thinks, has to do mostly with the way male/female roles among mammals have developed. Males don’t make much “parental investment” in their offspring — that is, they don’t spend much time with them like mama mammals do. Instead, to put it bluntly, the males spend all their time trying to score. This evidently is the most efficient way to perpetuate the species, which should be comforting news for all you guys trying to romance bimbos in the local bistros.

Interestingly, there are some non-mammalian species in which the males do suckle their young, notably pigeons and doves, who feed their babies “crop milk,” which is vaguely similar to human breast milk. And who knows, what with the Mr. Mom scenario becoming more common, we ultramacho he-men may yet find ourselves in the restaurant business. I personally am not looking forward to this — hell, I’m still trying to warm up to the the idea of changing diapers — but since it’s probably 75 jillion years down the road at the earliest, I’ve got a while to get used to it.

Send questions to Cecil via cecil@straightdope.com.

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