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Science Reporter, MARCH 2016 42
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MOTHERS are intensively involved in childcare. Dads, generally, do not
stick around to rear the young ones. But in nature, interestingly, we fi nd a reverse tradition in some species where daddies take up the cudgels to rear the young ones. Look around you and you will fi nd many amazing stories of devoted dads.
Let’s start with a lower group of organisms – sea horses, which exhibit a fascinating example of paternal care. Instead of the female, the male seahorses
carry the babies and give birth to the young ones. Male seahorses have a pouch where females deposit their eggs and then the males release sperms into the sea water and the eggs get fertilized. Males incubate them over a period of 5-6 weeks. In the meantime their body size increases. When the babies are fully grown male seahorses undergo muscular contraction for the birth of the baby.
The broad nosed pipefi sh also shows similar paternal features like the sea-horses. What’s more, in the pipefi sh the blood vessels in the pouch of the expectant father transfer food from the dad to the baby.
Paternal care, quite unusually, is also noticed in some species of the insect family. Giant water bugs are an example of doting dads. Male bugs carry eggs on their back until they hatch. They may carry as many as 150 eggs at a time for two-three weeks. They take care of the eggs by shading them, protecting them from predators and aerating them. Sometimes they fl oat in the intermediate of air and water to get maximum oxygen, which is required to hatch the eggs. They also dry them frequently so that eggs do not get mouldy. To protect their eggs from the predators, giant male water bugs deliver the most painful bites among all the insects.
The fi lthy looking frog which gives a repulsive feeling commands respect as it proves to be an adoring dad. Some frog fathers protect their tadpoles from predators such as insects by carrying them in their mouth. The tadpoles are sometimes embedded in the father’s skin
or on backs and legs to be saved from any harm as in the case of the midwife toad. The back of the male midwife toads have some wart-like structures which secrete smelly poisons to protect tadpoles from predators. Sometimes frog fathers develop specialized pouches to carry the young ones as in the case of the pouched frogs.
Among the birds, a very common example of an affectionate dad is the Emperor Penguin. The job of the father penguin starts after the mother lays the eggs. During this time, the mother’s nutrition level reduces severely. To survive the chilly winter the mother moves off to the ocean to feed. While the mother is gone, the father holds the eggs carefully within the “brood pouch” balancing it on the top portion of his feet. The father starves himself to take utmost care of his child. The chicks may be harmed due to sudden movement of the father penguin. So, he minimizes his other activities too. Another unique feature exhibited by penguin dads is that they can feed their babies by secreting a curd-like substance from their food-pipe if the mother fails to come back even after the hatching period.
Intensive paternal care is observed in the large fl ightless bird rhea. After laying eggs, the females go in search of another mate. Male rheas are left in charge of incubating the eggs which may vary from 10 to 60 eggs for a period of six weeks. If anything menacing, even a female rhea, approaches the little ones, he will not hesitate to chase them away. For the fi rst few months daddy rhea nurtures the
MUKULIKA MANDAL, BABITA SAHA AND SIRAJ DATTA
A male seahorse carrying its baby in the pouch
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Science Reporter, MARCH 201643
An intriguing example of paternal care is shown by a species of primate namely Pygmy marmoset. Male marmosets start caring for their child the day they are born by licking and grooming the new-born. The excessive strain undergone by the expectant mother makes the father more responsible. The father marmoset carries the baby on his back for the fi rst few weeks. He brings the babies to the mother when they are hungry. Cooperative care is seen in these animals. Several group members help rear a single infant or a group of babies.
Scientists starting from Charles Darwin tried to fi gure out reasons for this unusual deviation in parental care. Robert Trivers did extensive research in this fi eld. But a single reason failed to explain these behaviours. Fatherhood has been manifested independently in diverse groups of organisms. After Trivers, many scientists suggested many ideas. But parenthood in each organism has to be explained independently and there is no inter-relation.
But there is no doubt that there is an important role for fathers too – both among humans as well as in the animal world.
Mukulika Mandal is pursuing B.Tech (2nd year) in Biotechnology from Haldia Institute of Technology. Email: [email protected] Babita Saha is working as a senior secondary teacher (Biology) in Bhavans’ N S C Bose Vidyaniketan, Haldia. Email: [email protected] Datta is Associate Professor and Head, Department Biotechnology, Haldia Institute of Technology, ICARE Complex, H aldia, West Bengal-721657. Email: [email protected]
chicks independently and teaches them life skills.
Jacanas also prove to be active fathers. From nest building to protecting and incubating the eggs, father jacanas do their jobs effi ciently. The main job of the father Jacana starts after the female lays the eggs. He has to incubate the eggs which require a temperature of 32-38°C. African jacanas depend on solar energy for achieving the temperature. During hot days he leaves the eggs unattended under the sun but comes back in between to check if they are alright. He will shade the eggs if they have turned too hot or incubate them to bring up the temperature. On cooler days he stays in the nest incubating them to provide the required temperature. If the eggs are threatened, he will take them to another place under his wings. After the chicks are born father jacanas feed them, care for them and teach them the survival skills. Jacana fathers are exemplary homemakers. They even take care of eggs fertilized by other males.
Flamingo moms and dads are very vigilant parents and share their duties equally. Both the male and female fl amingo incubate the eggs by turns sitting on top of the nest mounds. During incubation they carefully turn the eggs with their bills. After the eggs hatch, the anxious parents look after the chicks. Father fl amingo keeps a protective eye over the young ones and makes provision for their food.
A good example of parenthood is exhibited by great horned owls. The father makes provision for food for himself and the expectant mother who is unable to fl y for food hunting due to her enlarged size. The female lays a few eggs during winter. After the eggs hatch, the father has to provide food to his new family members. The mother stays in the nest for the fi rst few weeks as the babies have diffi culty in maintaining their body temperature and need the warmth of the mother. During this time the father provides extensive protection to his family.
The animal world also depicts examples of the nuclear family. A wolf-pack with a father, mother and children is a characteristic example of a nuclear family. Wolves are excellent fathers. They are very attentive towards their kids. After a female wolf gives birth, she stays close to her little pups for several weeks. The male wolf plays the role of a protector, guarding the family from predators. He hunts for food to feed his new family. The father will give away entire pieces of meat to his babies even if the mother gives them regurgitated ones. As the young pups grow, the dad takes on the role of a strict, sometimes playful guide helping incorporate the pup into the pack.
MOTHERS are intensively involved in childcare. Dads, generally, do not stick around to rear the young ones. But in nature, interestingly, we fi nd a reverse tradition in some species where daddies take up the cudgels to rear the young ones. Look around you and you will fi nd many amazing stories of devoted dads.
FEATURE ARTICLE
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Male giant water bugs carry eggs on their back Flamingo parents look after the chicks
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