MANILA, Philippines -- The United Republic of Tanzania in Africa is willing to donate giraffes and elephants to the Manila Zoo in exchange for Philippine crocodiles.

The Philippines has more than enough crocodiles, said Manila Mayor Alfredo Lim who proposed the exchange to a 13-man delegation from Tanzania.

An animal-for-reptile exchange had earlier been proposed by Lim so the city could address its surplus of crocodiles and add to its animal collection. Lim said he was willing to exchange 20 of its more than 40 crocodiles for animals like elephants, zebras and giraffes.

Two tigers from Camp Farms in Palayan City, Nueva Ecija, and another crocodile from the Cayman Islands was recently donated to the Manila Zoo.

City veterinarians are also coordinating with zoo officials in Thailand and India about the possibility of getting some elephants.

Puerto Princesa Mayor Edward Hagedorn has also pledged to donate various kinds of animals to add to the zoo’s present stock.

The Manila Zoo began operations in 1959 with about 500 animals, according to the website of My Zoo volunteer group. These included 30 different kinds of mammal species, 63 reptilian species and 13 species of birds, said the group.

But many of the animals are now old and sickly.

Animal rights groups want the zoo dismantled and the animals set free, arguing that the imprisonment and display of innocent animals for the amusement of the human species was abominable.