SINGAPORE - More than 700 animals from across 131 species were born at the four parks under the Wildlife Reserves Singapore (WRS) in 2018.

Among the newborns were 35 species listed as threatened under the International Union for Conservation of Nature.

The standout success is the landmark breeding of the endangered Santa Cruz ground dove under human care at Jurong Bird Park, with 12 chicks born since late December, WRS has revealed.

Other notable newborns include a chimpanzee, a Celebes crested macaque, a pair of sloth bears and Malayan horned frogs.

Dr Cheng Wen-Haur, deputy chief executive officer and chief life sciences officer of WRS, said: "Our team of zookeepers and veterinarians have done us proud again with some outstanding achievements in conservation breeding.

"The world-first breeding of a Santa Cruz ground dove in human care is a significant step in establishing an assurance population of this species away from their natural home."

An assurance population refers to a colony of a species bred under human care, and ensures that the species does not go completely extinct even if it was to die out in the wild.

About 300 of the doves, which are native to Solomon Islands, are estimated to exist in the wild.

The first chick in the bird park hatched on Dec 31. More could be on the way as more eggs are incubated, in what is "a significant win" for the species, WRS said.

Jurong Bird Park also successfully bred three critically endangered straw-headed bulbuls last year, having hatched one in 2017.

According to the WRS, the park is the first zoological institution to breed the birds under human care in more than a decade.

The bulbul is threatened by extensive poaching for the songbird trade, and Singapore is the last stronghold of the species, with a local wild population of just over 200.

Meanwhile, Singapore Zoo had a prolific year in breeding amphibians, the WRS said.

In a first for the zoo, five tadpoles of the Malayan horned frog successfully reached froglet stage - the stage before it becomes an adult frog. To date, two of the five have survived and grown into juveniles, though the others died.

The species is "notoriously difficult to breed", as its tadpoles and froglets need precise environmental conditions to thrive, WRS added.

In terms of primates, the zoo welcomed a baby female chimpanzee, named Nini, in January last year. Nini is the 32nd chimpanzee to be born in the park.

The zoo also recorded its first birth of the Celebes crested macaque in seven years.

The critically endangered species, which is native to the Indonesian island of Sulawesi and its neighbouring islands, is threatened by habitat loss and hunting for bush meat.

At the Night Safari, zookeepers successfully brought up a pair of sloth bear cub twins, after hand-raising them to maximise their chances of survival.

The bears were born last September to an inexperienced mother and required constant care in the first few weeks of their lives.

Now five months old, the pair are preparing for their eventual public debut at the sloth bear exhibit.

At the River Safari, a giant anteater was born last year for the first time in four years.

Dr Cheng said the main goal of breeding wildlife in WRS parks is to achieve sustainable populations of species in human care.

"Depending on species and circumstances, these animals can be ambassadors for community engagement and education, and they may also serve as assurance colonies to safeguard against extinction in the wild," he said.

"The ultimate goal would be to return some of these zoo-born progenies (offspring) to their wild habitats some day when it is safe to do so."

WRS registered 540 baby animals in 2017 and more than 600 in 2016.