Keepers have spent the past week looking at all the suggestions submitted by readers of The Sun-Herald and decided on the Indonesian names that best reflected their cultural and geographic heritage, as well as their individual natures.

The first-born, a male, has been named Kembali (pronounced Kumbali - emphasis on the ''u'') which means ''return'' - a reference to the fact that only 400 Sumatran tigers are left. The second-born cub, a female, is to be called Katika which means ''the great''. The last-born, a male, will be called Sakti (pronounced Sarti) which means ''invincible'' or ''powerful''.

''It was a hard decision for the keepers but they decided on relatively short names that don't sound too similar,'' zoo spokesman Mark Williams said. ''It is important when conditioning them they can each recognise their own names.''

The cubs, born in August, are growing more confident and their mother Jumilah often leaves them to play while she rests. They have not been troubled by the recent heat - in the wild they are used to temperatures of 40 degrees and 100 per cent relative humidity.

The names will be entered into a database to help continue an international breeding program.

The winners of the naming competition: Biju Joseph, of Kogarah (for Kembali); Kwan Ie Djun, of Burwood East, Victoria (Sakti); and Barbara Young of Deakin, ACT (Katika).

Follow Environment on Twitter