SINGAPORE - On June 27, 44 years ago, the Singapore Zoo was officially opened by then Deputy Prime Minister and Minister for Defence Goh Keng Swee.

It has become one of the country's most notable attractions, and now attracts some 1.7 million visitors each year. It houses more than 2,800 animals from over 300 species of mammals, birds, and reptiles.

It has also become one of the world's best rainforest zoos.

Here are some significant events in the zoo's rich history.

1. Opening of arctic exhibit Frozen Tundra

On May 29, 2013, the zoo opened the Frozen Tundra, an exhibit modelled after the Arctic environment. Measuring 2,700 sq m, or the size of around 2½ basketball courts, it houses an ice cave, a large pool, and a waterfall.

Most notably, it serves as the home for the polar bear Inuka, the first polar bear born in the tropics and one of the zoo's most popular animals. In Frozen Tundra, Inuka has been able to enjoy life in Arctic conditions, and it has more space to move around.

While polar bears live for an average of 15 to 18 years in the wild and 25 in captivity, Inuka is now 26, or in its 70s in human years. It is currently in a special senior animal care programme.

The Frozen Tundra exhibit is also home to other animals, with racoon dogs and wolverines living in separate sections.

2. Death of iconic white tiger Omar

The zoo lost a familiar face on June 7, 2017, when 18-year-old white tiger Omar was euthanised due to health problems.

After developing melanoma, a type of skin cancer, the tiger's joints degenerated. Over the last three years, it was kept under close supervision and given supportive care by a group of keepers and veterinarians. But Omar's health kept worsening, prompting the decision to euthanise it.

Omar was born in Indonesia's Taman Safari, and was brought to the Singapore Zoo in April 2001, along with two female siblings.

3. Birth of the first Komodo dragon bred in Singapore

It took 34 years of attempts, and on November 15, 2009, the Singapore Zoo finally bred its first komodo dragon. It made the zoo the first in Asia to breed a komodo dragon outside of its native country Indonesia.

The reptile is the result of breeding between two imported komodo dragons; the male came from Portugal, while the female came from Japan.

Komodo dragons are the world's largest lizard species, have a lifespan of 20 to 30 years, and remain endangered.

4. Death of matriarch orang utan Ah Meng

The beloved orang utan Ah Meng died aged 48 - the rough equivalent of 95 human years - on February 8, 2008, leaving behind four children and six grandchildren.

Known as the face of the zoo, it both entertained visitors and promoted awareness of wildlife conservation, as its species - the Sumatran orang utan - is critically endangered.

In light of her role as a tourism ambassador and icon of the zoo, Ah Meng became the first animal that the zoo buried on its compound, with 4,000 people attending her funeral.

Its successor as the face of the zoo was named last year: its granddaughter, Ishta, who took on Ah Meng's name as well as the role.

5. Official opening of the Wildlife Healthcare and Research Centre

The $3.6 million centre, equipped to treat over 1,500 cases a year, has facilities such as a treatment room, a surgery room, a laboratory, an x-ray room, a pharmacy, animal wards, and a post-mortem room.

In the WHRC, aside from the treatment of animals, tissue samples from rare species are studied, so that they may be bred in the future.

Sources: The Straits Times, AsiaOne, Wildlife Reserves Singapore