From devoted, to deadbeat, to cannibal: How animal fathers survive in the wild

Jun 20, 2011

Some animal fathers help rear their young; some animal fathers actually become pregnant and carry their own young; some animal fathers are deadbeat dads; and some animal fathers may even eat their own young.

Join Dr. Stephen Vessey as he chats about the various ways animals choose to rear their young. How different are they from human dads? He will be online Monday, June 20, at 1 p.m. ET. Have a question? Ask now.

As I sit at my desk here in northwest Ohio, a male robin (identified by his darker head) has just brought a mouthful of insects and a worm to his nest just outside my window.  He seems to be working just as hard as his mate.  He was up at 0500 this morning singing away, defending his nest and territory.  Yesterday he joined others in mobbing a Blue Jay, a potential nest predator.  Why is it that so many species of birds are monogamous, with the male sharing the cost of raising offspring, whereas 95% of all mammal species show some degree of polygamy and relatively little care by fathers?  These and other questions are ones that I am looking forward to discussing in this afternoon’s chat.   Steve

It has been shown that some primates seem to mourn their dead. Do male Gorillas seem to show emotional attachment to their young?

I don't recall reading about this in gorillas.   In rhesus monkeys the mother often carries her dead infant with her for days, or even weeks, even when it is just a piece of dried up fur.  

Males (fathers?) occasionally carry infants back to their mothers if the infants get separated from the group, but I've never seen them show interest in a dead infant.  

Which animal dad do you think is the most fatherly?

I got this one earlier, but it may not show up yet;  here's what I said.

Hmmmm, I guess that's a matter of taste.  You might say the father sea horse, that takes the eggs into his brood pouch and sort of gets pregnant, continuing to care for his young after they are free swimming.  Or the male giant water bug that lugs the developing eggs around glued by the female to his back.   But my vote would be humans, where fathers have such a great potential to provide for their offspring and influence their outcome across many generations.  

Are there any other mammals, other than Man, where the Father takes an active role in raising their offspring?

In marmosets, small South American monkeys, the female typically gives birth to twins, with a combined weight of more than 25% of hers.  However, the male in this socially monogamous relationship does all the heavy lifting, carrying them around and giving them back to mom only for nursing.  Many other examples of male care in mammals can be found in the Carnivores, where males help bring food to the mother and her offspring.  

Why do male cats sometimes kill their offspring? I was told they fear they won't be enough food and wish to reduce the competition for food, but is that really the reason?

I've read about tom cats killing kittens.  My first question would be, are we sure it is the biological father?  Cats tend to be polygynous, so determining paternity could be iffy.  Some litters of kittens may even have more than one father.  My guess is that it is perhaps like in lions, where a new male moves in and removes the progeny from a previous male, perhaps inducing the female to come into heat.  

Males of the Northern Jacana are typically polyandrous, which is unusual amongst animals where polygamy is much more common. Are there any theories as to what leads to role reversals such as in the Jacana? What would be the advantages, if any, for males versus females in such roles? - Dr. Bobb

Dear Dr. Bobb:  You have me stumped here.  These birds show a complete role reversal, with females competing with one another, weighing nearly 50% more than the male.  It may have something to do with heavy predation on nests, where a number of eggs scattered among several nests defended by males stand a better chance of surviving.  Please feel free to enlighten us on this matter.   Dr. Steve

Are there more aminals that leave the raising to mom than that help raise their young?

Yes indeed.  Actually in most animals there is no care at all.  In birds, usually both dad and mom take care of the young.  In mammals it's almost aways the mom.  

Of all the animals in the world, which makes the best Dad?

Hmmmm, I guess that's a matter of taste.  You might say the father sea horse, that takes the eggs into his brood pouch and sort of gets pregnant, continuing to care for his young after they are free swimming.  Or the male giant water bug that lugs the developing eggs around glued by the female to his back.   But my vote would be humans, where fathers have such a great potential to provide for their offspring and influence their outcome across many generations.  

What about fish? Is it really truly like what "Finding Nemo" led us to believe?

The Nemo story makes more sense for fish that it does for mammals.  I discuss this in one of my answers that hasn't been published yet.  Because fish fertilize their eggs externally, Marlin can be reasonably sure he is the father.  He probably guarded  the nest in which Nemo was born.  Of course there were a lot of other eggs in the nest and there's no evidence that paternal ties last that long.   NSF is currently funding research on fish that is looking at just how much the fathers can influence the behavior and survival of their offspring.  

Male parental care occurs in a wide variety of animals ranging from insects to mammals, but in all of these groups, it is limited to only certain species. Are there any common factors across the animal kingdom that lead to evolution of male parental care?

This question has been tackled by a number of biologists.  The argument that makes the most sense to me goes as follows:  Among taxonomic groups of fish, about 10% have care by males only, in amphibians it’s about 9%, and drops to close to zero in reptiles, birds, and mammals.  This pattern no doubt has to do with the method of fertilization of eggs, external, which is most common in fish and amphibians, and internal, which is most common in the other three groups.  In external fertilization eggs are shed by the female and the male then sheds his sperm over them.  In this way he is in closer association than the female with the now fertilized eggs and is thus more likely than the female to care for them.  Additionally, he is most likely to be the biological father and thus has high confidence of paternity.  Where fertilization is internal, the female remains in close association with the eggs, so if there is going to be care, she is the likely candidate.  This is especially true if she mates with several males, giving the male little confidence of paternity.  Of course, there are many other factors involved, but this may be how paternal care gets started. 

Any young that eat their dad?? Thank you.

Not that I know of, but if anyone out there can come up with an example, other than humans,  please let us know.  

In the movie March of the Penguins the dad was shown as the protector and savoir of his eggs and young chicks. Is this real or Hollywood?

Mostly real.  The father incubates the egg during the long antarctic winter, but both the father and mother contribute heavily in the rearing of their lone offspring after hatching.

You mentioned cannibalistic behavior and seahorse dads in your intro. Are there any more strange or unusual dad behavior you could tell us about?

How about the discus fish, where mom and dad attach the eggs to some vegetation; after hatching the fry swim over to mom and dad and attach themselves to the skin and nourish themselves on skin secretions.   

Some years ago, I had a bull with my small herd of cattle. George was huge - weighed over a ton - and I kept him for years beyond usual bull longevity because he was easy for me to handle, until he learned that he could go pretty much anywhere he wanted to, gates and fence notwithstanding. But he had an interesting trait: in the spring, when the calves were born and after they got their wits about them, he would amble up to the males and carefully place his head against theirs, and push them back a few steps. Then, (and here's where it gets interesting) he would allow the calf to push HIM back a few steps. He was very gentle about the entire thing, and, of course, there was no way the calf could move him at all:he gave it to them. He'd do this a few times to each male calf in turn, and it reminded me for all the world of a father playing catch with his boys. I thought it was very sweet, but how on earth would something like a bovine come up with this idea?

That is an interesting observation.  We do not see much paternal care in bovines, given that males are kept busy trying to defend their females against other males, and given the likelihood that more than one male sired offspring in the herd.  However, you mention that George was an old bull, and likely the only adult male in the herd, so it is likely that these were his own offspring.  Thus, it would behoove him not to harm them.  If these are indeed his own offspring, we might also wonder if George could recognize them as his own, possibly via odor cues.  I observed similar behavior in rhesus monkeys, where the alpha, or dominant, male in the social group would tolerate youngsters, even letting them climb and play on him.  Although there are other adult males in these groups, the alpha male usually sires the most offspring.  As with your observation, these were most often young males.  Why that is the case would be a great topic for further study.

Is there any evolutionary advantage for male animals, such as lions or bears, to eat their young? Why would they do this? Is this because they don't have oxytocin?

Cannibalism by fathers is a bit of a mystery, and seems hard to understand from an evolutionary perspective.  Overall it is quite rare.   One factor explaining it in mammals could be a confidence of paternity issue.  If females mate with several males, how does the male "know" that he is the father?  As far as I know the killing of infants by male lions occurs by new, unrelated males that have just taken over the pride.  In this case they are eliminating unrelated offspring and inducing the females to come into heat sooner.  Other instances of killing of offspring by both sexes may have to do with eliminating weaker offspring, thus improving the survival chances of the remaining offspring.  

Regarding the hormone oxytocin, this and other hormones have been implicated in pair bonding and parental care in rodents and other mammals.  It is certainly reasonable to think that it is also involved in parental behavior in carnivores.  

Some dads eat their young?! Why would this happen?

Please  see my answer to a similar question.  

My time is up.  Thanks for the questions.  If I didn't get to yours, feel free to send them to me personally at svessey@bgsu.edu

By the way, re birds vs. mammals, father birds can do almost everything mothers can do except lay eggs, but father mammals don't lactate.  

What mamalian male species do participate in parental care? How much on an evolutionary advantage do these offspring get by having the fathers help out in the care?

 I addressed this to some extent in several of my earlier answers.  In rodents, a few species are monogamous, and the male provides care by keeping the young warm.  Lab studies show that young survive better with the father present.   In social carnivores, such as jackals and wolves, food is often scarce and both sexes bring food back to the mother and young.   In marmosets the mother is spared having to carry the relatively large young.  Presumably these all have an impact on offspring survival.  Although monogamy is rare in mammals, all of the monogamous species show substantial paternal care.  

In This Chat
Stephen Vessey
Stephen H. Vessey, Ph.D., is Professor Emeritus at Bowling Green State University, Ohio. He received his B.S. degree from Swarthmore College, with M.S. and Ph.D. degrees from The Pennsylvania State University. While at Bowling Green he taught animal behavior and mammalogy, also co-authoring textbooks in those areas. Since retirement in 2000 he has spent several tours of duty as a Director of the Animal Behavior Program at the National Science Foundation. His main interest is at the interface between animal social behavior and population dynamics. He has studied the social behavior and population biology of rodents (mice, rats, hutias) in Ohio woodlots, Cuba, the Virgin Islands, and coral atolls in the Pacific. He and his students also spent many years studying a colony of rhesus monkeys on islands off the coast of Puerto Rico. While not at the NSF he resides with his wife in Bowling Green.
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