Bokaro, Nov. 12: Having miserably failed to breed lions, tigers and hippos in the absence of mates, the authorities of Jawaharlal Nehru Botanical Park in Bokaro have finally sought the help of Central Zoo Authorities (CZA).

Zoo officials said the Sanjay Gandhi Botanical Garden, Patna, the Kaziranga National Park, Assam, and the Bhilai zoo have already shown interest in an animal exchange proposal. But the seal of the CZA is required for the same.

While Kaziranga is ready to send a young tiger couple, the Patna zoo is keen on sending a pair of healthy hippos. Bhilai has agreed to send a couple of young lions.

In return, the Bokaro zoo would have to give them exotic birds, whose population has been growing steadily because there is a hatchery here.

The population of black bucks and leopards is also increasing, the officials said. The only leopard couple gave birth to five cubs last year, they added.

But the problem remains with lions, tigers and hippos. At present, the park has two male Royal Bengal Tigers — Ram and Vishnu. Both are sworn enemies. Two years ago, zoo officials had introduced them to a tigress, but both Ram and Vishnu decided not to mate with her.

Zoo vet Gautam Chakravorty said winter was the mating season for animals of the panther family such as lions and tigers. The park has two male hippos and two male lions, who are also longing for female partners.

So, the zoo authorities are planning the exchange as soon as possible.