Singapore Zoo celebrates 40 years

People take photos of "Inuka" the polar bear in the frozen tundra enclosure at the Singapore Zoo, June 27, 2013.

Home to more than 2,800 animal specimens from over 300 species, 26 percent of which are threatened, the zoo has attained a strong reputation internationally for its conservation initiatives and breeding programs.

The zoo celebrates its 40th anniversary on Thursday, June 27, 2013.

S.R. Nathan, former President of Singapore, and Claire Chiang, chairman of the Wildlife Reserves Singapore, feed elephants during the zoo birthday bash celebration at the Singapore Zoo, June 27, 2013.

A baby orangutan is seen during the zoo birthday bash celebration at the Singapore Zoo, June 27, 2013.

People visit the white rhinoceros enclosure at the Singapore Zoo, June 27, 2013.

Meerkats are seen at the Singapore Zoo, June 27, 2013.

People visit the white rhinoceros enclosure at the Singapore Zoo, June 27, 2013.

Zebras are seen at the Singapore Zoo, June 27, 2013.

Former President of Singapore S.R. Nathan feeds the orangutans during the zoo birthday bash celebration at the Singapore Zoo, June 27, 2013.

Children from the Movement of the Intellectually Disabled of Singapore (MINDS) prepare backstage ahead of the zoo birthday bash celebration at the Singapore Zoo, June 27, 2013.

Female Nyalas are seen at the Singapore Zoo, June 27, 2013.

A young girl watches "Inuka" the polar bear in the frozen tundra enclosure at the Singapore Zoo, June 27, 2013.

A Hamadryas Baboon is seen at the Singapore Zoo, June 27, 2013.

People take photos of the giraffes at the Singapore Zoo, June 27, 2013.

A white tiger tries to catch its food during feeding time at Singapore Zoo, June 27, 2013.

People view a female Nyala at the Singapore Zoo, June 27, 2013.