Other zoos across the country have shown little or no interest to receive lions and tigers, as they cannot afford the cost of up keeping these animals. Apart from this Dhaka zoo does not have any exchange programme with zoos in the world, and the authority is at a loss with these spare animals.

The World Association of Zoos and Aquaria consider gender separation 'bad animal welfare', but Dhaka Zoo, having no choice would resort to gender separation instead of a permanent contraceptive method.

"We are helpless, and have no other alternative. The excess inmates consume nearly 60 percent of our annual budget, " said Dr NC Banik, the zoo's deputy curator.

Banik also said that zoos in developed countries use vasectomy or hormone treatment for the cat species but they were not capable of doing so.

Zoo authorities had decided on a sterilisation programme such as vasectomy of the fertile male cats in 2005, but dropped the idea due to lack of sufficient funds and expertise.

Although two pairs from each species is sufficient for visitors and researchers, the Zoo houses an excess of 22 lions, 16 tigers, 200 axis deer, 28 pythons, seven hippopotami, and some other species, all born in the Dhaka Zoo.

The most expensive among these extra inmates are the lion and tiger as they eat up a major portion of the zoo's annual budget.

Zoo officials say they spend Tk 99,19,280 a year to feed the excess number of inmates, which amounts to 59 percent of an annual budget of Tk 1 crore 70 lakhs to feed animals.

"We have not purchased new animal species in a long time because of this extra pressure on the annual budget. The zoo lacks animals like the kangaroo, giraffe, ape, dolphin and many types of birds," said the deputy curator.

On the other hand inmates like the baboon, rhea, chimpanzee, and waterbuck have remained single for long with no reproduction because of the lack of the opposite sex.

The zoo authority said exchange is very necessary to get rid of this deadlock.

The authorities propose to sell excess axis deer at a nominal price.

"The cost of an axis deer is now Tk 24,000, but we have requested the ministry to reduce the price to Tk 15,000," said Banik.

The Dhaka Zoo has not yet got membership in the World Association of Zoos and Aquariums (WAZA), the world's largest association of Zoos.

Officials believe that WAZA membership would help Dhaka zoo to find a solution to the existing problem.

"Being a member of South Asian Zoo Association for Regional Cooperation (SAZARC) we are hopeful that we will be granted membership in WAZA soon. WAZA had recently enlisted SAZARC into its Association", said Mostafizur Rahman, Dhaka Zoo's curator.