They may not be answering mating calls out in the wild, but at Mandai, Singapore, it seems some endangered species are having a baby boom. More than 180 animals were born at the Singapore Zoo last year under the parks' captive breeding programme. Of these, 14% are endangered in the wild.

Doing spectacularly well last year were the primates, who saw three proboscis monkeys, two douc langurs, one Bornean orangutan, one lion-tailed macaque and four cottoned-top tamarins join their tribe last year, all of which are on the endangered list of the World Conservation Union. Other animals born last year include three Nubian Ibexes, also endangered, and a Malayan Tapir, two Jackass penguins, and a pygmy hippo, all animals considered vulnerable to endangerment.

The parks' executive director attributed the success of the breeding programme to sound husbandry practices, expertise, and the dedication of zoologists and vets.

Every aspect of the animals' lives is monitored carefully to ensure that the animals breed successfully — their temperatures are monitored every day, their diet is carefully designed to provide maximum nutrition, and minerals and vitamins are given as supplements.

Last year, the zoo also set up the Wildlife Healthcare and Research Centre, with a new ultrasound machine to better detect pregnancies and internal ailments.

Notable successes of the zoo's captive breeding programme include Inuka, the first polar bear to be bred in the tropics and a giant flying squirrel, believed to be the first to be born in a zoo in Asia, in 2004.