As a river flows again, crocodiles and turtles get a second chance at life

Over the years, heavy sedimentation caused by dumping of debris and encroachment in the Vishwamitri river had decreased the river’s carrying capacity and created obstructions in its course, causing recurrent floods in Vadodara. After one of the worst such floods in August last year, the government, acting on the directions of the State Human Rights Commission (SHRC), finally announced the flood mitigation project that was first proposed in 2008.

While the dredging and desilting part of the programme were undertaken by the Vadodara Municipal Corporation and the Narmada Water Resources and Water Supply Department, the conservation exercise was handled by Devkar and his volunteers. Devkar is part of a committee of environmental experts appointed by the SHRC to supervise the Vishwamitri project.

The Vishwamitri river runs through the heart of Vadodara. (Source: VMC)

According to a report by the committee, the riparian zone of the Vishwamitri is a biodiversity hotspot, home to ants, bees, aphids, locusts, grasshoppers, lizards, calotes, toads, frogs, snakes, civets, porcupine, mongoose, jackal, fish, molluscs, turtle, crocodiles, and microscopic forms of life. But it’s the crocodiles who rule its dark waters, with an estimated 440 of the reptiles in a 25-km stretch of the river, according to the crocodile census conducted in February by the Gujarat Ecological Education and Research Foundation and the state forest department.

Since the pre-monsoon dredging and desilting exercise coincided with the breeding and nesting period of several of these species, the conservation programme had to be inbuilt into the larger project.

Moving the eggs to safety

So every morning, before the excavators moved in to desilt and dredge the river, Devkar’s team of volunteers would start combing the banks to look for eggs. Devkar says that while reptiles such as turtles and crocodiles dig holes in the soft soil on the riverbank to lay their eggs, the red-wattled lapwings lay “perfectly camouflaged eggs” that can only be spotted by trained eyes.

Eggs of the red-wattled lapwing being incubated at Vadodara’s Sayaji Baug Zoo. Volunteers had rescued 38 of these eggs from the banks of the Vishwamitri. (Source: Special Arrangement)

“One has to lie in wait since these birds are extremely deceptive. They fly in circles and in different directions to throw off anyone trying to approach their egg clutch. The trick is to observe the bird and, eventually, it will fly to its eggs. Even then, the eggs are hard to spot. You could be standing right next to one and fail to spot it,” he says.

The volunteers initially moved the eggs of all the three species to a safer spot on the riverbank for 24 hours. Then, between March 26 and June 7, in a “one-of-its-kind project”, 410 of these rescued eggs were handed over to Vadodara’s century-old Sayaji Baug Zoo for safe incubation and hatching.

In all, the volunteers rescued 88 crocodile eggs, 284 turtle eggs and 38 bird eggs. Of the crocodile eggs, zoo curator Dr Pratyush Patankar says, 34 were found damaged on arrival, as were 126 of the turtle eggs.

Devkar says the volunteers did their best, even photographing the eggs before moving them to improve their chances of hatching.

Crocodile eggs being incubated at the Sayaji Baug Zoo in Vadodara. Of the 88 crocodile eggs rescued from the banks of the Vishwamitri, 34 arrived at the zoo in a damaged condition. (Source: Special Arrangement)

He says, “The photographs were of utmost importance since there is a difference between the incubation of bird and reptile eggs — when birds sit on their eggs, they tilt and turn them over a couple of times in a single day. So if you don’t turn them, the embryo gets stuck to the egg shell and dies. However, in the case of reptile eggs, if you move them from the position in which they were laid, the embryo drowns in the albumen.”

Patankar says the eggs came labelled and identified by the section of the river from where they were moved.

Incubation and hatching

While the zoo has a good success rate for hatching bird eggs, thanks to the advanced incubators and brooding chambers in its aviary, incubating reptile eggs was a different ball game.

Curator Patankar says the infrastructure for reptile eggs was put together after meticulous research. “Incubating the eggs of the red-wattled lapwing was easy, but, for the reptiles, we had to certainly put in a lot of effort to replicate the riverbank environment.”

A team of veterinary officers Dr Yash Parmar and Dr Brijesh Lunagariya, assistants Minesh Parmar, Dharmesh Barad and Rohit Solanki, and zoo education officer Manav Mehta followed a painstaking schedule at the highly restricted hatchery enclosure. “During the entire period of incubation, the hatchery was completely cordoned off. We had to ensure no infection was carried into the incubators,” says Patankar.

Crocodile hatchlings being released back into the Vishwamitri. (Source: Special Arrangement)

The most critical aspect for the reptile eggs, he says, was to maintain the right temperature. “A temperature of 29.5 degrees Celsius ensures that the male-female ratio is nearly 50:50. Beyond that, in the case of crocodiles, it would mean more male hatchlings than females and vice versa in the case of turtles.”

At the zoo, a simulation nest box was created for the reptile eggs since they dig holes to bury their eggs. “We cured large plastic boxes with soil to mimic their natural environment. We also tried to stick to the same setting in which the eggs were found. We also covered them with a muslin cloth and regularly sprinkled water to maintain the right humidity levels.”

The hatchlings of the red-wattled lapwings, Patankar says, were kept in a brooding chamber for about 48 hours before being released at the same spot on the riverbank from where they were rescued.

“By the end of July, we managed to successfully incubate 16 crocodile eggs, 26 turtle eggs and 20 of 38 bird eggs, all of which were released. The successful hatching of the turtle and crocodile eggs in the zoo hatchery was nothing short of a feat,” he says.