There are endless examples of offspring reared by two parents, a group, no parents, or single parents. In some species both parents work together to feed and raise their young, but in other species, such as turtles, the offspring are left on their own to survive. The more common occurrence is that the offspring are raised by one parent, which is typically assumed to be the mother. For mammals this is a safe assumption considering the mothers give birth to their young and feed them with mammary glands. However, there are some examples of single dads in the wild. Almost everyone has heard of male seahorses who incubate the eggs for several weeks before hatching, but there are other examples as well.
Greater rheas are a flightless bird species from South America in which the male will build and protect a single nest. During mating season he will mate with up to twelve females who will all lay their eggs in his nest. Each females clutch consists of five-ten eggs, which means this dad may have to raise up to 80 hatchlings! He will then incubate the eggs for around two months surviving on very little food and raise the hatchlings until they are around six months old. They will very aggressively protect their young, even from female rheas.
Male Marmosets from South America will carry, feed, and groom their offspring and also act as midwives during birth. They groom the newborns right after birth. These primates live in groups of three to 12 individuals. Females typically give birth to twins, which is 25% of her body weight. Due to the high cost of birth for females it is predicted that males make up for this by raising the young.
Hopefully people start to give more consideration to the effort any parents in the animal world put into their young, both mothers and fathers!
Posted by Caitlin Descovich O’Hare (7)
http://scienceray.com/biology/some-of-the-best-animal-dads-in-the-animal-kingdom/
I never knew that males took care of the babies, I have never heard an example of this behavior. I know that male penguins will incubate the egg while the females are out gathering food to feed the new born chich, which is a role reversal for hiw many animals do things. The dad is not alll alone in this though, the females come back and take care of the baby. I wonder if in species that the males take care of the eggs if there is female competition for mates and if mating is a male choice system? This would be interesting to find out because males would want the females with the best genes since they are the ones caring for the offspring.
ReplyDeletePosted by Noelle Kellicker
Hi Caitlin,
ReplyDeleteI am just wondering how many hatchlings make it to the six months? Since the father is barely eating and is continuously protecting and fighting for his offspring, how does he survive?
Also when all those females lay their eggs in that one single nest, isn't there competition? I would suspect that other females would try to throw other females eggs out of the nest.
Posted by Whitney Huynh
So, there are animals with dead-beat moms. I, like the previous commentor, am also curious to the survival of the rhea hatchling. If the father is looking after roughly 80 eggs, there must be extreme competition among siblings for food and attention. There must be several deaths, it's just a matter of how many survive. Their developmental rate must also be a big factor, as the faster they become self-sufficient, the better their chances of survival. I will say that the mother primate does have a good excuse for being a dead-beat mom, you would be one too if a quarter of your body weight came from birthing children.
ReplyDeletePosted by Austin Gray
Well, fatherhood in nature is always an interesting topic. Personally, I am fond of seahorses. To me, the males seem like the pinnacle of fatherhood, considering they are the ones who give birth. It's rather a refreshing switch, seeing the males of a species contribute to the rearing of the young in anything other than a protective or procreative respect.
ReplyDeletePosted by Jacob Lane
I'm very curious if anyone knows how something like this would have evolved. You said that in marmosets it is because the female uses up 25% of her body weight so it makes sense for them to do that. I wonder how this evolved independently so many times and if there is an obvious reason for it or not? You may or may not know the answer but it seems like an area that definitely has potential to be explored more.
ReplyDeletePosted by Janelle Hayes
This article was pretty cool. I'm curious to know what the social hierarchy of these creatures is like. Do the responsibilities of child rearing fall onto the less dominant sex in these species or are there other underlying factors?
ReplyDeletePosted by Michael Thomas
It is definitely much more common to see females bringing up their young by themselves, so it is interesting to hear the opposite case. Also, I cannot believe the babies make up 25% of the females body mass. I wonder if death after birth is very common for the woman, and maybe why the polygamous behavior in the male evolved for this reason. If the females are dying off, it would make sense that the strong and capable male takes care of as many babies as he can, so the females genes can be passed off somehow.
ReplyDeletePosted by Abbie Saranteas
The first thing that came to my head was Finding Nemo when Marlin was taking care of Nemo all by himself. The male sea horses probably has some way to lower their own metabolism to be able to store food for a long time and use less energy for normal behaviors. Otherwise I can't imagine how the male sea horse is able to survive .
ReplyDeletePosted by Jobin
Its amazing the the male is able to survive for so long, and have the energy to take care of so many hatch lings with such a small amount of food. What is the female doing while the male is rearing the young?
ReplyDeletePosted by Emily Nobrega
Noelle, There are also several other examples, although most of them include the male simply incubating the egg and co-parenting with the mother as you mentioned with penguins. I am not sure if this role reversal also reverses completion to the females. I know that Greater Rhea males are sedentary during breeding and females come to them to mate, so this shows there is not much competition in this species as the female goes around and mates with numerous males.
ReplyDeleteWhitney, Although the clutch size may be up to 80 eggs it is more typical that it is around 25 eggs. Survival rates, as you have guessed, are fairly low. Around 45% of chicks will survive until autumn of those that hatch. I am not quite sure what the father does for food during this time, but there have been examples of other parents who will lose significant amount of body weight while caring for young.
Austin, Similar to my response to Whitney, the survival rate is not too good based on the number of eggs that are laid. Of those hatched only 45% survive. They are almost full size at around 6 months and I am sure they become better able to survive on their own before that time is up.
Jacob,It is rather nice to learn about the fathers of the animal kingdom since we usually hear about the sacrifices many mothers make for their young. Another interesting topic are those fathers who actually die in producing young. It would be interesting to know if they are aware of it in any way.
Janelle,I tried to research the causes of males in this reverse role although I could not find much out there. Of course seahorses have the anatomical feature of a pouch to care for young, but it would be interesting to see how this has evolved.
Michael,I know that male seahorses will become very aggressive over female attention although they still put less energy into reproduction, as it costs females more energy to produce eggs than it costs males to incubate them.
Abbie,I did not see anything particular about higher rate of death in Marmoset mothers than other mothers of the animal kingdom due to birth. Although I would not be surprised if it were true due to how much it costs to give birth.
Jobin,It is a sort of Finding Nemo situation, that movie is very popular in this blog! Actually for the male sea horse it has been found that it costs less energy for them to hold the babies than for the female to produce the eggs.
Emily,The females go around and mate with a large number of males during breeding season and so remain fairly mobile. In the spring the females often form flocks with other females.
Posted by Caitlin Descovich O'Hare
I believe this is a good change of scenery. Not taking anything away from mothers who raise offspring but it is rare to see males in the animal kingdom take care of young like this article showed. This reminded me of male penguins in Antarctica which incubate there eggs under their belly to keep them warm for months in the winter. All this goes on when females go to sea to capture fish for themselves and eventual young.
ReplyDeleteposted by: Andrew Ryan
It is certainly not well known outside the biology field that the male species can be the one to raise the young. I do wonder why there are so many more females that raise their young rather than the males. It must be very special circumstances to make male parental care more viable. This is a rather stark contrast to the birds of paradise that have absolutely no help raising their young. I wonder if there is more male parental help in regions that are colder or have less food/ resources. Is there a relationship between parental care and longitude?
ReplyDeletePosted by Caroline Adams