Motherly love of a savage beast

Crocodiles are seen as ruthless killers lurking in the waters ready to attack humans. People also say that they are so ruthless that the mother crocodile even feeds on its young. Are crocs that savage?
Two weeks ago, ZooLander reported about the giant crocodile which was killed because it hunted a man that went near the marsh it lived in. Human-crocodile conflict has existed in many areas, with occasional attacks unfortunately tagging these aquatic reptiles as ruthless man-eaters.
‘Crocodile mothers are so blood thirsty, that they eat their young just as they emerge from the eggs’ is something most people believe. There are many who say they have witnessed croc mothers eating their young. Yet even the most menacing creatures in the animal kingdom usually care for their young. So what made crocodile mothers so ruthless?
There is a saying which goes ‘the eyes don’t lie’, but if you do not observe everything closely, even what your eyes see can be deceiving. It was herpetologists who first observed that crocodiles do not eat their young. Crocodiles being held in captivity helped inmaking this observation. What people see as croc moms trying to eat their young is in fact them carrying them in their mouths to a more secure place.

The young are vulnerable, that’s why they got mommy
Crocodiles usually build their nests on the bank of a river, or near a lake, an area where both land based and water based predators lurk. Though crocs are one of nature’s deadliest animals, their babies are still vulnerable to predation. This gentle act by crocodile mothers most definitely help save the lives of lots of their young for sure. And though they carry their babies in their mouths, they are ever so careful not to bite them. Like a cat moving its cubs to safety by lifting them from the skin of their necks carefully, croc mothers too take extra care not to close their deadly jaws while the babies are inside.
Scientists also believe there is chemical recognition between mother and juveniles, so she can recognize her own offspring and the young crocs also use several types of calls to communicate with the mother crocodile to solicit her protection. However, the young crocs are fair game for other adult crocodiles! The female will try to defend them, but quite a few crocodiles are eaten by larger crocs before they reach maturity. Scientists say this cannibalism actually serves a purpose - when populations are healthy, and there is no need for large numbers of juveniles to enter the population, their mortality is very high. However, if the population is low and needs to recover, the survival rate of the juveniles becomes much higher and many more survive to become adults. It’s a tough life being a crocodile!
This journey into the water, caught between jaws with a series of sharp teeth, would definitely be a memorable first tour in life, for croc babies. But this act is not the only behaviour that shows the gentle, caring side of a crocodile mother.

The importance of temperature
First of all, the crocodile mother ensures her babies get a comfortable bed until they are hatched. Croc mothers usually build a mound from vegetation and mud, and then dig a hole at the top, into which they lay their eggs before covering them over. A clutch of eggs can have as few as 8 eggs and as many as 80. Crocodile eggs take about 85 days, or almost 3 months, to incubate.
There is also amazing findings which say, that the sex of the embryos of the eggs, are decided by the temperature to which they are exposed in the nest. Scientists have found that crocodile embryos do not have sex chromosomes, and unlike humans their sex is not determined genetically, but by temperature. If the eggs are exposed to a temperature of around 31.60C (890F), these eggs will turn in to male crocs while the females are produced at slightly lower and higher temperatures. The decomposing vegetation in the nest mound provides warmth to the eggs, while the mother stays close by, guarding the nest site.
Guarding the nest is not a habit prevalent in other reptiles, which just lay eggs and moves away, leaving the babies to survive on their own. However, unlike other reptiles, crocodile parental care doesn’t stop there. The mother will guard the nest until the eggs are ready to hatch. Then when she hears the babies (called “hatchlings”) calling from within their eggs, she will open the nest and help them come out. Mother crocodiles will sometimes help the babies hatch by gently cracking the eggshells in their mouths.
The baby crocs form a ‘crèche’ - a small group that the mother will defend vigorously. Not a bad mother to have, you might say! Eventually, after several weeks or months, the juvenile crocodiles split up and disperse to try and find their own habitat, saying good bye to their beloved mother that had taken care of them, so very well.

Love even in captivity
There are facilities, similar to zoological gardens, that are specifically made for crocodiles. The most famous one is the Madras Crocodile Bank located in India. However Zoolander also found an interesting research conductede by the St. Augustine Alligator Farm in Florida, USA. They usually separate the eggs once the mother croc lays them in the mound nest, and hatch them in artificial incubators. But when they let a mother take care of its young instead as part of the study process, they reapedsome very interesting results.
They had selected a Siamese crocodile for this experiment in the year 2000. One week after the eggs were laid, the zoo based researchers gently opened the top of the nest and checked the condition of the eggs. After they allowed the eggs to hatch naturally, one morning 7 weeks later, they had noticed the mother croc lying on top of the nest. Her head was cocked sideways, seemingly listening.  After the lapse of an hour the hatchlings began coming out of the nest. As the zoo researchers watched, the female slowly used her front legs to pull dirt away from the top of the nest. When she uncovered a hatchling, she gently picked it up in her mouth and carried it to the water.  If she uncovered an egg that was not yet hatched, she gently broke the egg with her mouth, scooped up the baby and again carried it to the water. Sometimes the hatchlings were still attached to the egg by their yolk and both baby and egg would be carried to the water.  One little guy had quite a struggle - the egg he was attached to started to fill up with water and began to drag him under.  He was pulled partially under water before he managed to wiggle his way free.
All this goes to prove that zoos too can be used easily, to research the behaviour of animals. The Colombo zoo too, will soon provide many opportunities to study the behaviour of the animals in captivity, with the aim of relating these behaviours to animals in the wild.  Research, in fact, opens our eyes to the real situation, as in the case of crocodiles.
Many of us believed that crocodiles were just ruthless blood thirsty man-eaters, but they are as gentle as human moms, when it comes to parental care. True, they are dangerous animals in their territories, but let’s not make outcasts of them and have a grudge and kill them whenever a crocodile is sighted.

Published on LakbimaNews on 04.03.2012